blurnj13

A diy is a bit rough I think for this, since I think you really do need to have a good mechanic background. There were several places where one little mistake would have caused billman to take apart the rest of the engine. Then again if you have all the time in the world... I'm sure anything is possible. Billman did mine in 2 hours flat =p.

Squeezer

wow

mikegarrison

Yes, I completely replaced all my retainers and valve springs, but it was a PITA and I did drop one of the tiny little tapered "cotters" down into the engine! Fortunately, I was able to get it back using a magnet.

You need an air compressor. You need a leakdown tester. You need a valve spring compressor that actually fits. you need to have the skills and tools required to remove the camshafts and then replave them again.

It took me more like two months than two hours (usually working only for several hours on weekends).

There are some specialized tools that would have made the job a lot easier.

blurnj13

Funny you mention that, cause Billman had a custom valve spring compressor he made just for the task.

BlownAP

it would be great if billman could chime in and let us know what spring compressor would work for this job,

iv only done valve springs on a chevy head with the head off the engine

krazik

I'm not billman but this is what he has and what I have too. You have to grind the metal ears off one side to make it fit better.

http://buy1.snapon.com/catalog/item.asp?P6...ore&dir=catalog

krazik

I did all of mine in 4 hours (just replacing the springs and retainers, not including all the head dis/re assembly).

I did it over 2 days on a weekend

RED MX5

If Bill says it's OK, then I'm sure it is OK, but I too wonder about the extra mass and how it works with the higher red line and possibly more aggressive cam profile and stiffer springs. For now I'm content to inspect the OEM retainers when we change the oil, and unless we start seeing catastrophic failures in cars that haven't been over reved I'm sticking with that program. This latest find concerns me, because the cracks are so small; I'd feel better if we had some idea of how much longer they'd have gone before failing. If the small cracks grow slowly then periodic inspection is sufficient, but if a small crack can translate into a dropped valve without any other warning then periodic replacement might make sense.

Bill, have we actually seen cars dropping valves without ever having been over reved?

Kyushin

Bill definitely has a great reputation and i trust his word on using Ap2 retainers in an AP1, im just curious how the extra weight would effect the margins at redline, and would he recommend some stiffer springs to add alittle buffer?

mikegarrison

There's some learned skill involved, and I did the second half of them in about 1/10 the time I did the first half.

That particular tool was fine for the OEM springs, but it sucked for the dual springs I replaced them with. It would keep slipping off the inner spring coils.

Also, I did it by myself, and the big hassle was getting the cotters reinstalled. If I had had just a third hand available (or if the spring compressor would have worked better on the dual springs) it would have been much easier.