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Update on the Monster 2.8L Type 4 project. As we left off I was having issue with the AA performance cylinder heads. They were leaking at the cylinder to head area and the intake valves were all leaking after less than one hour of run time. I sent the heads back To AA at their request for inspection and repair. They had the heads for a month and told me they found nothing wrong with the heads and they supposedly measured them to check that the seating areas were the same depth on both chambers of each head. They also told me the cleaned and lapped the valves. My engine builder received the heads back this week and checked them. The heads are off by .003" from one side to the other. He removed the valves and they have ridges in the seating face which should not be there on valves that have been run less than a hour. We are guessing the steel the valves are made of is too soft. So I am finished with AA performance products . I would recommend anyone else to proceed with caution if thinking about buying from them. I reported what we found to AA and asked them for a full refund upon the return of the heads but have not had a response from them. I ordered a set of LE200 heads from the type 4 store today. The heads won't be available until May. They are built by Hoffman Automotive. They appear to be amazing heads and should be for what they cost. They should be the finishing touch to make this engine as amazing as it should be. I will let you all know how the engine runs and what power it makes on a chassis dyno sometime in late May I hope. Anyone want to buy a set of type 4 heads cheap? Maybe they can be used as cores for a complete rebuild?

Looks like I may luck out. AA has responded and they want the heads and intakes sent back in response to my request for a refund. Let's see if  I get credited back on my Credit card. Cross you fingers. I will be better off with the LE200 heads, they are supposed to be amazing. The specs sure seem to say so. I have bought a 6500 rev limiting rotor for the distributor so I don't have a repeat of the sticking throttle disaster LoL..

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Last edited by Jimmy V.

When you have an engine that has separate cylinders as our Type 1 and Type 4 engines have it makes it a must that the cylinder heads are perfectly parallel. The measurement I am speaking of is the depth of the head where the cylinder and the head seals. If the depth of one head chamber is different from the other it will cause the head to not lay perfectly flat across both cylinders and then they will leak compression and not seal. In this case one cylinder sealing area was .003" lower than the other. This is fixable by anyone with a good machine shop and some know how. If this was the only issue my engine builder would have touched the head off and made it parallel. The valves leaking and looking like they did was a more troubling issue. We think the valves were made of soft material or the valve guides are not perfectly in line with the valve seats causing the valves to hit the valve seat out of square. They should not have had the ridges worn into the valve edge. So being as we returned the heads for inspection and repair once and were told the heads measured to be perfect and were good to go and they came back still not right, I decided it was time to bail on these heads and buy the LE200 heads that appear to be nothing short of amazing. I should have known from past experience. Good heads make the engine and buy the best heads your budget will allow. That said, I was happily surprised that AA Performance has offered to refund my money upon the return of the heads and port matched intakes. I have to say this is at least a sign they want to make this right and do the right thing. At the end of the day the engine is going to end up better because of this ordeal.

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