Some...Assembly Required by Richard Atwell (c) Copyright 2004-2011

or: How I Learned to Stop Worrying and Love the Budget Rebuild.

You wouldn't think that installing a rebuilt engine would be difficult but when you throw used parts into the mix (including parts used for the rebuild) anything can happen and probably will.

Although far easier than rebuilding your own engine, there are enough gotchas involved with a purchased rebuild that you should plan the replacement of the engine with an eye for details as if you were rebuilding it.

My friend's motor overheated on the highway in his 72 bus two weeks after the purchase from the original owner. The #3 exhaust valve stretched, the valve head dropped off and pounded a hole in the cylinder in about 5 seconds. This failure is pretty common failure for a VW engine and hard for a new owner to prevent without a) a maintenance history indicating the valves were going tight b) inspection of the engine after purchase.

The Day the Engine Died:

The bus must have been overheating for a long time with no CHT gauge installed to indicate any problems and the receipts that went back to the original dealer invoice did not indicate any problems. Two items of note are that the bus was equipped with a "factory" a/c unit and the timing was retarded for smog control which make the engine run hotter than necessary.

When the engine overheated, the bus slowed to a stop and there was smoke all over the engine compartment. At first it looked like an electrical fire but the starter refused to budge the engine and the bus wouldn't roll in gear when pushed: the engine had definitely seized.

Tearing it down, there was metal everywhere inside the crankcase and with the one head and one piston toast it was clear we had better start from scratch:

Building your own engine is always the best choice if you have the skill and tools and time (I have argued this opinion many times and my answer is simply that it's the only way to ensure the engine is built to your specifications). It's also fun and very satisfying to be able to drive around with a sense of pride in a bus with an engine that you built yourself.

For those who don't have time/tools/skill, they must rely on an engine rebuilder. In a utopian world you would locate the "old German guy" in town who has been rebuilding VW engines for 20 years with a proven track record. Unfortunately, not only is this expensive but the supply of old German guys is forever drying up. Putting the cost aside there is also the time factor as the case and various parts need to go to several machine shops so they are reconditioned properly. Even most local rebuilders do not have all of the in-house machinery.

At one time, VW dealers were able to order remanufactured engines from VW of Canada. Those engines cost about $2k + $1,300 core fee but are no longer being built. Also in that price range was renowned Type 4 engine builder Bob Donalds (aka Boston Bob and recently passed away). Boston Bob's list of satisfied customers was very long and he was in the same tier as the old German guys but unfortunately he passed away Oct 23, 2008.

The other option is a budget rebuilder for a Type 4 engine and there are a few popular choices (but not limited to):

• AVP Worldwide
• JCS Volks Machine
• Fast German Auto (dead link)
• GEX

According to feedback from Type2.com list members and Samba forum members you will get a good longblock from the first three but you should avoid GEX like the plague. If your GEX engine lasts 10k miles, you will be a statistical freak. Their engines are built with mismatched case halves and other atrocities. Think of GEX as the Maaco of the VW engine builder world: the PO used them solely in order to help sell you the bus with no consideration for longevity. GEX used to operate in California but it appears they moved to Arkansas to avoid paying out lawsuits. Feel lucky thinking you can beat the odds and save a few bucks? GEX Lawsuit information.

For some reason a few mail order companies sell GEX engines for about $2000. I can only speculate that it's an indication of the insurance they have to charge you to cover failures. Why do reputable companies sell GEX engines? Any engine that keeps a bus running means more part sales I guess.

Based in California, AVP has a good reputation for rebuilding Type 4 engines. We chose to purchase an AVP engine through Bus Depot and although the BD catalog only shows a few engines part numbers you can purchase anything listed on the AVP website. For example, we needed a '72 1700cc with no smog ports on the heads (AVP #611) and that's what was ordered.

The engines are drop-shipped from AVP and unless you live in PA, there's no sales tax to pay if you order through Bus Depot. BD charges you a core fee and round trip shipping in addition to the engine. The core fee is a deposit that is returned when you ship back your old longblock. If there is any damage they may prorate your core or simply not give you any. They are mainly interested in the condition of the case and crank and rods. The pistons and cylinders are thrown away and although they rebuild the heads they do not factor them into the core fee.

Shipping is charged up front and if the round trip shipping that AVP pays comes to less, Bus Depot refunds you the difference. For example we paid $1065 for the engine + $200 core + $275 ship = $1540. Our final bill was $1540 - ($275 - $185 ship) - core = $1450 because they rejected our core as reusable. The engine is delivered to your garage and you ship the old long block back on the same crate within 90 days. You can use anything to secure the engine to the crate except for duct tape (sounds crazy but AVP says it happens).

Getting from longblock to install-ready condition is an involved process. There are a lot of pieces not included that you will need from your old engine as well as new gaskets and hardware. This is a step by step guide to that assembly process so you are ready to install.

New Longblock:

From what I can see, AVP Type 4 bus engines get:

• Some oil galleries tapped and plugged so they don't blow later.
• German gasket set, German Viton flywheel seal and new Kraco pulley seal
• New pistons and cylinders
• Heads rebuilt with new exhaust valves, reground intake valves
• New pilot bearing
• Flywheel shims

The specific details of their rebuilds are mentioned on their website. They recommend calling to find out exactly how they will be rebuilding your engine.

AVP sometimes use the head gaskets that VW has recommended not be assembled with the engine.

Even though the bulletin only specifies 2L engines, all Type 4 engines can suffer head gasket failure. You will get the gasket if you have rebuilt VW heads. If the rebuilt heads are from AMC then they will leave out the gasket.

Optionally you can ask them for a flywheel which they will send you for $20 after they have step cut it. (The $20 is deducted from your core fee upon return). When you request the flywheel they will set the endplay for you otherwise you have to perform that step yourself. What shims they are supposed to send you if you don't order a flywheel isn't clear. Strangely enough they do not install the flywheel for you if you order one so the blame for flywheel seal leaks are on the customer.

All engines are hot tested on a rig using a special flywheel for 45 mins after the oil temperature is brought up to 170F. They perform a compression test, check oil pressure and look the engine over for leaks before shipping it to you. The distributor drive pinion is installed for you and locked down so it doesn't move during transport.

You supply the engine tin and induction system of your choice and engines come broken in although like any engine you should take it easy for the first 1000 miles and be careful not to let it idle in high heat.

Warranty:

AVP is very specific about warranty issues. They recommend that you have the engine installed by a qualified VW technician as well as taking the bus to a mechanic for maintenance. Finding a good mechanic is almost as hard as finding a local engine rebuilder these days. AVP now require 45 days to return the warranty card instead of the 5 day limitation to active the warranty.

Warranty is 12 months from date or purchase or 12k miles (whichever comes first). It is non-transferable from the original purchaser. Items rarely covered in their warranty:

1. Burned or seized pistons
2. Loose cylinder heads
3. Excessively worn piston rings
4. Engine failure due to dirty or low oil
5. Burnt or bent valves

Problem #2 would seem to be their fault (they don't recommend re-torquing the heads after break-in) but the rest seem reasonable reasons for rejection.

If a problem develops they require you to call the AVP warranty manager at the provided number before any repair work other than diagnosis is started. They will provide instructions on how to proceed. You must not disassemble the engine prior to the warranty claim. The warranty is limited to parts and labor and does not include towing charges, oil or time lost while the vehicle is out of use. Engines must be returned in original state of purchase (undressed state!) and shipped at the owner's expense.

If you have to make a warranty claim you may have to pay a mechanic to diagnose the problem. In the event that the engine requires a warranty repair you will have to drain the fluids and ship the engine back to AVP at your expense. If you don't live within driving distance to AVP, these shipping charges ($100+) can really add up.

At some point you may you decide it's simply more cost effective to replace parts instead of having AVP repair them. It will void your warranty but as it is already so limited (12k miles) and so expensive for you to execute, your decision will depend on the cost of the repair. Plus, the time it takes to send the engine back to the rebuilder leaves your bus un-drivable for a long time (weeks) compared to having a simple repair done locally.

Parts:

AVP provides the under cylinder tin installed so you should send that old tin back with your core. Keep everything else! You will need some new gaskets and fasteners in addition to the tin from the old engine to complete your install. Whatever is left over from the gasket set used to assemble your engine is sent to you by AVP along with the engine to help with your install.

Here's the list of additional parts you'll need to order:

All models:

72-74 only:

75-79 FI only:

Optional

- these item should be replaced to minimize future repairs:

Transmission

While the engine is out you may want to service these hard to reach items if they haven't been replaced recently because paying for a clutch R&R will be $400-600 at the mechanic:

AVP's Gasket Set leftovers

Included in your shipment so use in favor of your old ones:

These are leftovers from a 1700 gasket set. The 1800-2000cc gasket set is slightly different. See my Gasket Set article.

Lastly, is your flywheel surface good or does it need to be step cut? How about the fingers on the pressure plate: are they worn down? Do you need a new spring for the clutch lever or need to re-grease the throwout fork? See my Transmission Refresh article for details.

Always start with new spark plugs, cap, rotor, condenser, wires, etc so no gremlins jump from your old engine to the new one.

For exact hose lengths and part numbers see my Vacuum Hose and Fuel Hose articles. Some of the details in my Dual Carb Vacuum Hoses article are a work in progress still because they do not cover all models yet.

Reminders:

Before assembly, AVP reminds you that they have set the valves and the endplay for you (the latter if you purchase a flywheel) so you only need to fire it up when assembly is complete (you still need to double check their work). They provide these caveats in their documentation:

Assembly:

• You must not rotate the engine until after the distributor is in place or this may cause the driver gear to dislodge itself.
• Make sure intake is free of leaks and adjusted properly. A lean mixture due to leaks or misadjusted or dirty carburetor can cause seized pistons or damaged valves and heads.
• Be sure the intake manifold is cleaned out thoroughly. Debris left in the manifold from a previous engine failure will find its way into your new engine and damage pistons, valves and heads.

Cooling:

• The shrouding must be installed as air-tight as possible with no pieces missing. Any loss of cooling air will result in an overheated engine.
• The engine compartment seal should be replaced if necessary. If not, this will allow preheated air into the cooling system.
• Be sure to add the proper amount and grade of oil for your climate. Too little oil wold cause a lack of lubrication.
• Make sure the fan is clear of paper, leaves, rags and other debris that would cause a loss of airflow through the cooling or reliability of the engine.
• Make sure oil cooler is replaced with a rebuilt unit.
• Check catalytic converter for blockage.

Tuning:

• Set ignition timing and points properly for year and engine type. Check total advance not just initial advance (static).
• Adjust the float level and choke properly. A rich gasoline mixture will cause excessive ring and bearing wear.
• Non-stock accessories on the engine can void your warranty if in the determination of AVP, it affected the performance or reliability of the engine.

In other words restore the engine to a factory condition. Some issues to consider when your engine isn't 100% stock:

1. If you have a non-stock carburetor you may have warranty issues because AVP reserves the right to determine if it was the cause of overheating and/or damage.
2. If you have an a/c compressor and a huge gap in the tin you may be in violation of the AVP warranty. Seals all gaps in the tinware!

Step by Step Assembly:

So how do you get from longblock on the left to the ready to install engine on the right?

See more photos at AVP Install Gallery 1
and the rest at AVP Install Gallery 2

Because the engine is aircooled its operating tolerances are limited. Before you run the engine you MUST ensure the following:

1. The valves are adjusted correctly
2. The timing is correct and the distributor is advancing correctly
3. The thermostat system is working correctly
4. The engine compartment is sealed
5. The exhaust system is sealed at the head

If you don't, you will overheat the engine, ruin it and blow your warranty immediately. Because the rebuilders are only selling a longblock, the risk the engine will overheat is upon the purchaser. They can only guarantee that the engine won't seize on its own. If they repeatedly did this they would be out of business.

I highly recommend purchasing an Engine Stand. Working the floor the entire time it will take you to perform your careful assembly is uncomfortable and slows you down. Further, assembling the exhaust system with the engine at that level is absolutely no fun.

Before you install:

1. Sealing the exhaust

2. You should plan to retorque the heads after you've run the engine with the exhaust system attached to obtain the best seal.

3. Before installing the engine in the bus you should check the compression by cranking the engine over on the floor. If you don't have a starting apparatus you can use your transmission and starter. Using jumper cables, connect the battery positive to starter terminal 30 and the negative to a good ground on the transmission (like the clutch cable Bowden tube mounting bolts). Connect a remote switch between starter terminal 50 and the battery positive. Be sure to remove all of the spark plugs to allow the engine turn over easily.

4. Prime the oil galleries using an oiler with the same weight of oil used in the engine. Squirt the oil through the oil pressure switch hole until it overflows. If your oil pressure tester has a long hose, crank the engine over until the oil comes out of the hose end and then attach the gauge to it.

5. Confirm that the thermostat flaps easily swing open on their own and that the bar isn't bent. Make sure the thermostat moves the flaps as the engine warms otherwise the engine may overheat.

Gotchas:

With something as complicated as an engine built for this low price there are bound to be problems. If there weren't folks like Boston Bob would be out of business.

Installation, operating and maintenance errors can compound these issues which makes it difficult for companies like AVP to offer a decent warranty. They are basically a mail-order longblock company but some people forget that.

Here's my experience and advice to help you get it right before you run it:

1. CHECK THE GASKET SET CONTENTS. One oil cooler seal was accidentally out of the gasket set. Some of the gaskets in the set are very hard to locate separately such as the oil filler gasket (meaning you may have to purchase another gasket set although AVP will send you an extra upon request).

   

2. The 210mm flywheel they sent me had two dowels on the back (they are for the TDC marker on 73-79 models). When they welded over the oil gallery plug behind the fuel pump, they used too much weld and I couldn't rotate the flywheel more than 330 degrees. I had to grind down the weld (which I mistakenly called JB weld) before the flywheel could rotate and clear the dowels. CHECK THE FLYWHEEL ROTATES. To add insult to injury, the case did not include the TDC Marker so I had to cover up that hole myself using a blank (a quarter works) and some JB weld. This problem probably only occurred because it was a case that had a mechanical fuel pump. They probably tap and plug this oil gallery plug on FI cases that cause no flywheel issues.

   

3. Leak-down - When I inspected the longblock on the engine stand, exhaust valve #4 was leaking down 50% while the other valves were within 4%. I performed the test several times to confirm and I had to send the engine back to AVP (They requested I install it and run it or send it back). They sent the engine back and said nothing was wrong with the engine and another leak-down test on that same cylinder now showed only 4% leakage. They must have run the engine on their hot tester because my new oil filter was full of oil.

   However, now #3 intake leaks down more than before when it was leaking down 4% before. I can only conclude that the way AVP builds their heads you have to pound the valves into the seats during the break-in or this head is bad. Either way they are instructing us to install and run the engine so that's what we are going to do.

   They also told me that they do not lap their valves because professional head builders do not do this. Well, head builders do lap valves for a perfect seal if you pay them so AVP is basically saying you don't get lapped valves at these prices. Or looked at another way, their valve job won't benefit from lapping. PERFORM A LEAKDOWN ON EVERY CYLINDER. You'll want to hit the valve stem with a dead blow hammer to seat the valve before you record any final readings on cylinders with large leak-down numbers. Here were the final set of numbers before installation:

   Cyl	Leak-down
   #1	8% rings
   #2	2% rings
   #3	12% intake
   #4	2% rings

   

4. I removed the problem head to see why it was leaking down so badly before I returned it. I filled up the exhaust port with mineral spirits and it instantly leaked into the combustion chamber verifying the leak-down results. When I re-torqued the head the original leak-down dropped to 30% so RETORQUE THE HEADS before you completely assembly the engine. Be sure to use penetrating oil on the nuts every time you remove the heads so you don't undo the studs.

   

   The arrow points to the location where we had the major leak. I recommend that you tear down the head and inspect the valves and seats for concentricity and the valve guides for clearance before running the engine (more below) because the leak-down tests aren't conclusive on a never run engine. You need a tube of prussian blue to perform this test otherwise you can use mineral spirits like I did without disassembling the head. If you remove the head you will violate the warranty terms but in my opinion it's the only way to determine whether or not the head will seal correctly.

   Also notice the reused intake valves with some material welded to the face.

5. The valve train was missing the washers to separate the shaft spring from the rocker arms. They installed the washers when they returned the engine after I pointed out that they were missing. I believe the washers keep the oil under the rocker arms and keep the spring compressed to the correct length. There are two styles of spring: this type that require the washers and a later style introduced in early 1974 with ground end faces that do not require the washers. Later valve trains eliminate the spring completely. SCRUTINIZE THE VALVE TRAIN.

   

6. Each time the engine came back from AVP the valve adjustment was horribly done. AVP provided worn out valve adjusting screws and they told me they re-used the old screws because they are the correct harness and the new ones may not be. These screws were so badly mushroomed they made adjustment impossible.

   AVP says they adjust the valves for you but I found their initial adjustment to be way out:

   Cyl	In	Ex
   #1	.008	.006
   #2	.010	.011
   #3	.011	.008
   #4	.007	.008

   When the engine came back the second time with their replacement screws I requested (aftermarket unfortunately) the adjustment was just as messed up:

   Cyl	In	Ex
   #1	.005	.004
   #2	.004	.008
   #3	.004	.008
   #4	.008	.011

   I had to replace the valve adjusting screws with genuine screws from the VW dealer. Inspect the valve adjusting screws and READJUST THE VALVE CLAEARANCE. This is what the original screws that they sent looked like:

   

7. AVP initially said the engine compression tested to 140psi but that number is too high for a never run engine. When I tested it myself, the cold readings were: #1 100, #2 110, #3 100, #4 105. This same tester reads 135psi on my own warm engine so I know it's accurate. PERFORM A COMPRESSION TEST. I wish they would simply send the engine test card to you. Whatever was written on their test card was not relayed to me and instead they quoted me the spec and caused a lot of confusion.

8. The spark plugs threaded into the engine fairly easily although not perfectly but after the engine was shipped to me the second time I had trouble with 3 out of 4 spark plug holes. CHASE THE SPARK PLUG THREADS. One hole is still difficult to thread the spark plug into which is unfortunate. In my opinion these threads should have been repaired because they are only going to get worse. Only chase the threads with the head removed (I don't trust those new tools that don't require head removal because they claim to catch all of the filings).

   

9. AVP set the endplay to 0.12mm. It really should have been set to 0.09mm as the wear limit is now very close. RECHECK THE ENDPLAY and have a new flywheel seal because you will ruin the old one removing it to replace the shims if you need to. You don't get a chance to mic them either in this state. AVP says they expect you to recheck the endplay so I don't understand why they don't let you install the seal yourself.

   

10. AVP did not take enough care to make sure the distributor will seat with the correct index of 12 degrees. CHECK THE DRIVE PINION. I searched the Type2.com archives and sure enough they get this wrong all the time. I even talked with them on the phone about this and they couldn't not explain why they install it wrong. I do: the gears are helically cut and they don't double check their work or don't care if it's only 1 tooth off. The first photo shows the excessive distributor rotation to achieve 5 ATDC timing. The second photo shows how the pinion is one tooth (30 degrees) in excess of the correct position.

    

11. These are the solid lifters AVP installed. They are not new but have been reground as evidenced by the radial marks. The dark circle in the middle means these lifters are worn out.

    

So those are the problems I encountered with this rebuild. You may have some of these, maybe others. The important thing to remember is that the earlier you find the problem the more you can do about it. Except for the heads, not of these problems were major but I would recommend you correct them all the same.

Break in:

AVP includes instructions in the crate. You should follow the directions and during break-in use a 20w50 oil in warm climate but a thinner oil like 10w40 in colder climates. Do not use synthetic based oil until the engine has reached 1,000 miles. It's generally considered "too slippery" and you want the new engine parts to break in. You will find that the engine gets stronger as it reaches the first 3000 miles and expect to see metal in the oil trapped in the oil filter from the bearings.

AVP's break-in instructions are so:

• 300 miles - change oil and adjust valves
• 800 miles - readjust hydraulics valves at 1 turn (they claim the Bentley method of 2 turns is incorrect).
• 1300 miles - change oil (and re-adjust valves)

AVP states in their documentation to perform the second/third oil change at 500/1000 miles but after talking with them on the phone they really mean additional mileage from the first oil change (300/800/1300) not the total mileage (300/500/1000).

AVP recommends a valve adjustment with the oil change every 3000 miles thereafter. That adds up to a lot of labor if you have a mechanic take care of your bus as he has to adjust the valves every oil change. I think what they mean is you should check your valves every 300 miles. Now would be a good time to learn how to check your own valves in 15 minutes or less.

The gasoline they insist upon is 92 octane per VW's recommendation. On the surface this appears to be the common RON/ROZ mistake but I gather it's insurance against overheating the engine due to pre-ignition.

Travel Log:

Odometer 49133 original miles.

• Mile 0 - 50psi cranking oil pressure. Engine sounds good. Oil leaking onto heater boxes probably from rotating the engine on the stand.

• Mile 100 - Engine is 100% in tune, peppy and driving nicely. Oil still leaking.

• Mile 312 - Replaced oil, filter and cleaned strainer. Oil no longer leaking. Put some Hylomar on the valve cover gaskets for insurance (part of the #1/2 head is gashed under the gasket). AVP must have painted or treated the case. I say this because a) it's a slightly different color from factory and b) the upper oil strainer gasket and the valve cover gaskets were badly stuck to the case.

  The Brazil oil strainer tore during cleaning so we had to replace that with a new one. The oil in the filter had an expected sparkle to it from the break in. AVP silicones the sump plate with the red o-ring which makes complete drainage to remove bearing material difficult.

  Adjusted valves and re-synced carbs. Some valves ok, some tight so most were reset to spec. Lots of tappa-tappa-tappa at startup but once warm sounds like a nice Type 4 engine with the stock exhaust (some fweem!). These were the clearances after 300 miles:

  Cyl	In	Ex
  #1	.005	.002
  #2	.005	.006
  #3	.001	.001
  #4	.002	.005

  I don't understand why #1/3 exhaust valve is going tight when AVP ok'd the head. We are not detecting abnormal exhaust noises but it would appear that my leak-down test was conclusive after all. The AFR is good, vacuum is good, etc. and the head temps have been between 290-330F. The only explanation I can think of is that the valve job was crummy as the leak-downs had indicated or perhaps the exhaust manifolds did not seated correctly. I'm going to watch the valves and see what happens (Note: In hindsight I should have done another leak-down test at this point).

• Mile 735 - Engine started to run rough so it was returned to me for repair. I pulled plug wires one by one to find that pulling #3 made no difference. I performed a leak-down on cylinder #3 and could not build enough pressure in the cylinder. When I took off the valve cover #3 exhaust valve was tight again. Backing off the rockers arm to standard clearance made no difference to the leak-down test: 90% leakage.

  The engine will have to be removed and stripped down for further diagnosis of the failure.

  One of the heat tabs, by spark plug #4 has "popped" and the one by #2 fell off completely and was lying in the lower deflector tin so there's little point in returning the engine. These tabs are industry practice and are designed to pop at a specified temperature. If you exceed that temperature for an instant going up hill in hot weather, you've just lost your warranty. The engine rebuilders keep the "pop" temperature a secret.

  AVP's warranty requires you to send the engine back to them strapped to a pallet with fluids drained. Quite a hassle. They do not pay for shipping the engine to them and will only pay the return shipping if the problem is their fault. This is the nature with mail order not AVP's fault.

  At this point, we are going to forgo the any attempt to claim on the warranty and put the cost of shipping towards rebuilding the heads using another head rebuilder. I had a gut feeling about those heads but I was lured into the comfort zone of the warranty. In hindsight I should have disassembled their heads when the engine was delivered a second time to check the valve seats and returned the engine before firing it up for refund if I was dissatisfied. Here are the leak-down results:

  Cyl	Leak-down
  #1	7% exhaust
  #2	70% exhaust
  #3	90% exhaust
  #4	7% rings

  Basically we were going to lose compression on both heads very soon. Performing a forensic on the head with prussian blue and a dial indicator revealed:

  • #3 exhaust seat was not concentric with the valve (way out as the leak-down had predicted).
  • several other valves had seating problems although not as serious as #3 exhaust
  • #3 exhaust valve had stretched. Luckily we lost compression before the head of the valve potentially fell off.
  • Every exhaust and intake valve had too much stem to guide clearance
  • Only a 1-angle valve job was performed and some seats were cut right to the edge

  One head had copper spacers under the valve springs, one head did not: I'm not sure if the spring tension was balanced between heads or if the springs were still good.

  

  The pictures tell all: a low budget valve job. Up until I examined the heads in detail, I had doubts about the assembly although I performed a leak-down and tried to plug the exhaust to force air past the manifold seal. Since we didn't have any indications of leakage besides the heads, we were just doomed from the start by the valve job. Clearly this head was built as fast as possible and the seats cut very quickly with a grinding stone.

  We had heads repaired by Adrian Audirac of Headflow Masters. Adrian charges $175 per head for a valve job and he only uses new springs, new valves and new guides. Leak-down results with the new heads:

  Cyl	Leak-down
  #1	4% rings
  #2	4% rings
  #3	5% intake
  #4	10% exhaust

  I disassembled Adrian's heads to inspect them, clean the seating surfaces and lap them with fine lapping compound. I only found some minor valve rock on #2 exhaust valve and all of the rest were well within spec. I also checked the seats with prussian blue to examine the valve seats. Adrian did an excellent job of installing new seats, valves, valve guides, springs. Consider AVP sells heads for $189 this, Adrian is a bargain.

  Adrian also replaced the exhaust studs with 8x9x56 oversized studs because two of them pulled when I removed the heater exchangers. Adrian didn't get the alignment of the studs exactly right but I was able to get the heat exchangers to seal properly.

  Adrian told me the heads he received had:

  • valve seats that were not the correct hardness
  • reused intake valves that were out of spec
  • contact faces that were resurfaced too much

  The expression in his voice when the described the quality of the heads was one of disbelief. He said, and I quote, "basically a pile of junk put together", unquote. His opinion certainly concurred with my own examination. AVP cuts the valve seats so deep the seat pockets were damaged and oversized valves had to be installed. Obviously the heat was responsible for some of the damage but not all.

  If you just need new heads, get them from Adrian. Rimco is another head rebuilder I would trust.

  Adrian used grinding stones instead of an angled cutter so we decided to lap the valves ourselves although he offered to do it for extra. After lapping, the leak-down increased a little on each valve. The leak-down tests give you an idea of the head's sealing ability but you can't take the numbers too seriously: only a visual inspection truly counts. Major leakage will howl and you are listening for that. Minor leaks will just hiss slightly.

  We used Loctite 39598 (aka Clover brand lapping compound in the duplex can; 120/280 grit coarse/fine). Lapping compound is a silicone carbide grit suspended in grease. You MUST remove all of this grease otherwise a spec of grit may find itself between a bearing and a moving part and become impacted.

  

  DO NOT SKIMP ON THE VALVE ADUSTMENTS OR CLEARANCE INSEPCTIONS! Do not be lulled into a sense of comfort because the engine seems to be running correctly. Inspections are your main defense against preventing catastrophic failure. Whomever you buy heads from be sure to disassemble and inspect them before you run the engine even if they are from the rebuilder with the best reputation: everyone makes mistakes.

  The engine is finally back in the bus and ready for a second tune-up.

• Mile 815 - Checking valve clearances and compression.

  Since the camshaft was already broken in I ran the heads for 50 miles before I checked on the heads.

  Cyl	In	Ex
  #1	.005	.004
  #2	.005	.005
  #3	.007	.006
  #4	.006	.006

  The 3/4 head is perfect but the 1/2 head lost some clearance. I will move the CHT probe from #2 cylinder to #1. I wish there was an affordable gauge that could scan multiple cylinders but there isn't so I'll had to build one.

  Cyl	Compression
  #1	125
  #2	123
  #3	125
  #4	124

  Average results for the rebuilt engine so far.

Core Inspection:

I highly recommend that you tear down your core before you send it in. If you are hesitant to do it because you think you might damage it, the risks of not doing it are greater. If your core suffered catastrophic failure (seized, hole in piston, etc) the damage may not be 100% visible from the outside. In our case a lifter bore must have been damaged from the inside by the valve head that went through the piston. Because machined surfaces are so precise even minor damage may ruin the core. If this is so, you will be paying a lot of money to ship the core to the engine builder who will simply not use it and then offer to charge you more shipping to return it to you. I would advise splitting the case and if you are not sure what to look for, take the case halves to the local VW repair shop and have them take a look.

Shipping:

The engine weighs about 185 lbs strapped to a pallet. The engine arrives in a cardboard box (not a crate) and wrapped with plastic to keep it protected from the rain. Removing the straps is difficult and they may have damaged the cylinder fins in transport so inspect that before you sign the driver's release form. I recommend securing the core you will return with rope. It can be difficult unless you use a good rope that bites into itself so you can tie secure knots.

Some trucks have lift gates and some do not. This is a hydraulic lift at the back and the shipping companies charge extra for them (maybe $25). I've seen drivers remove the pallet all by themselves without a lift gate and it's nerve wracking to watch them do it so lend them a hand or at least spot them.

Opinion:

To AVP's credit they did turn around the engine return within a week over the xmas holiday. I wasted a lot of time inspecting their engine, hitting roadblocks, lifting, packing and unpacking but this is the nature of mail order when problems arise. It's disheartening for the customer eager to drive their bus with all these delays. Certainly if you rely on your bus as a daily driver you will be sidelined too much and I recommend you go with a full-time mechanic that can work on the engine while you work.

I'm hoping that we just had a bad run of luck and that this experience is not indicative of the budget rebuilders in general. If so, this is a shame but I can understand why at the price we are paying. The shipping costs, delays and goof-ups we endured were all preventable before the first engine shipped. I only lived 136 miles from the vendor so imagine the delays living across country from them.

In our case I suspect it would have taken 3 engine deliveries to get it right and this has to be the exception, rather than the rule. Please keep in mind the purpose of this article is not to bash a particular vendor. At these prices I'm simply trying to raise awareness about these rebuilt products so your rebuild lasts as long as possible and installs easily for you.

Very small businesses rarely answer their phone or returns your calls right away and sometimes take days to turn around email replies with no dedicated phone/email support person. This may not seem important but when you are broken down expect a week to go by before you can even agree to take it a mechanic under their warranty scheme as you negotiate. Some of these business are Spanish speaking and have trouble with English so bear that in mind.

One area where I will be critical of AVP is that while they are quite polite in their communications they make few apologies. I do not like the business tactic of initially blaming a mystery employee or sub-contractor for their mistakes even though they correct them when asked. If the flywheel is wrong, the distributor drive is wrong or a stud is the wrong length, their first response is to blame somebody else even though they are honest and will send you the corrected parts. No apology or excuse is necessary: just send the friggin' parts. It's aggravating enough to be stopped dead in your tracks by a simple problem they overlooked.

At these prices it's up to YOU to double check the rebuilder's work to ensure the engine will install for you the first time without any issues. The rebuilders will all tell you they've been in this business for 10-20 years but when you hit an installation obstacle even after you've ordered the engine for a certain model year they will backpedal and claim there are too many differences to keep track of.

Would I install one of these engines from any other rebuilder without performing all of the checks I did? No, of course not because they are all reconditioned products and require careful scrutiny. At these prices, understand that the rebuilders reassemble motors mostly from used/reconditioned parts and some new parts. If you bought new parts for a rebuild it would cost $1200-1300 so consider the quality of the parts they are using even thought they get discounts for purchasing parts in volume.

Occasionally a customer gets a bad motor because it's an extraordinarily bad collection of parts. As the customer you should insist that your own motor be used as a core, especially if the previous engine had never been rebuilt so engine gets better than average quality used parts. The core used might have formally been a GEX (consider that). This idea assumes you have good parts to begin with so inspect them before sending off your core to a rebuilder who will agree to this. This process may take a little longer but it's extra insurance put towards a better rebuild. In our case we would have like to have re-used our own lifters.

Would I order heads from AVP in future? I have to say no in my case. Maybe you will have better luck. They appear to build a sturdy smooth running short block (very smooth) but their heads are the biggest weakness and there have been many reports of failure and I suspect they are not building them in-house but instead buying them from the lowest bidder. This is a shame because the rest of the engine is fine. I strongly recommend that they refine their head rebuilding process, upgrade to a 3-angle valve job and raise their prices if necessary.

We sent our heads to Adrian for repair because the heads were obviously flawed from the beginning and AVP claimed there was nothing wrong with them. Although we were still within the warranty period I decided I couldn't depend on a reliable repair in these circumstances and I was not going to ship the entire engine back a second time because of poor workmanship. I recommend that you buy heads from Adrian Audirac of Headflow Masters because of his stellar reputation and reasonable prices. Expect a 2-3 week delay because he is so busy. Make sure Adrian gets the stud repair correct if you have it performed.

Getting it right the first time remains my expectation for a mail order longblock engine because of the shipping costs and you cannot not count on an engine warranty in your decision making: it is not as easy as driving to the stereo shop to return your broken DVD player.

As for the mail order process in general, based on the potential shipping costs, I feel it's a much better to buy an engine locally and pick it up yourself IF you have the option available to you. This is no problem if you have another bus or friend's bus to transport the longblock and even renting a truck is inexpensive compared to shipping costs. The local sales tax you will pay will be cheaper than shipping charges and far cheaper if you have to send the engine back for a warranty repair. If your core is bad and you didn't catch it, then you'll only be out some gas money instead of more shipping charges if you deal with a local rebuilder. If only the head is bad, the rebuilders won't let you send the head back by itself because of their warranty restrictions. This is a HUGE hassle with a mail order engine.

As these vehicles get older NOT having a local rebuilder is far more likely than having one nearby. On top of that, many VW shops don't care about the Type 4 engine and turn around some of the worst engines and head rebuilds. The only way to avoid this is to have a local reputable 914 rebuilder do it and pay Porsche prices but that's still no guarantee. Because of this dependency on mail order for the majority of bus owners finding a reputable engine builder is paramount and why I've provided this feedback to help you understand the issues involved and what you need to examine with your own longblock before you fire it up.

Check the Type2.com archives for the experiences other people had. The #1 problem I read about is that the distributor drive gear is often installed 180 degrees or 1 tooth out. Most companies can't stay in business if their failures out number their successes so there are obviously many satisfied customers.

Head rebuilders:

• Headflow Masters (HotVWs Ad)
• Rimco (aka Jack Riddle Machine Co.)

References:

• My Engine Removal article
• My Engine Stands article
• My Engine Inspection Tips article
• My Exhaust Sealing article

• Engine Break-in (Aircooled.net)
• AVP Shop Tour

History:

12/12/04 - Created
01/15/05 - Updated after install
02/12/05 - Updated after head failure
04/04/05 - Heads back from Adrian
09/07/11 - Fixed broken photos, added translate button, updated footer
07/15/19 - Google update: new adsense code, removed defunt translate button