2 eta engine questions

[EtaSport]

1: Is the 9.0:1 compression ratio too high for a low boost turbo? Something in the range of 5 psi with no more than 7.5. I want to use stock internals and basically make this thing look and work like it came factory installed.

2: How is everyone finishing their valve covers? I have tried twice now and i still havent gotten it right. I sprayed the whole thing, let the paint dry, cure, and then proceeded to sand the ridges down with a sanding block. Looks like the best way to do it is mask all around so the sandpaper doesnt interfere with the paint and breather opening (i had this problem). But how do you get in the really tight spots? for instance the three small ridges on the other side of the ICV plate.

I appreciate any help. Thanks,
jon

[808BMW]

Re: 2 eta engine questions

1: Is the 9.0:1 compression ratio too high for a low boost turbo? Something in the range of 5 psi with no more than 7.5. I want to use stock internals and basically make this thing look and work like it came factory installed.

2: How is everyone finishing their valve covers? I have tried twice now and i still havent gotten it right. I sprayed the whole thing, let the paint dry, cure, and then proceeded to sand the ridges down with a sanding block. Looks like the best way to do it is mask all around so the sandpaper doesnt interfere with the paint and breather opening (i had this problem). But how do you get in the really tight spots? for instance the three small ridges on the other side of the ICV plate.

I appreciate any help. Thanks,
jon

I'm not too good with turbos, but if the gas is good in your area, and you have a good intercooler, I would think you could get away with it.

Why are you getting anything other than the ridges? Most people only polish the ridges themself, not the area in between.

[EtaSport]

Yea, I am only doing the ridges, but for some reason my sandpaper keeps scratching my paint, I masked off the paint around the edges so I wouldnt scratch it, but yet i still had trouble getting all of the ridges sanded down. I will have to snap a picture of it tomorrow or when I get a chance to show you what i mean.

On the turbo question. I know it would probably be best to put a thicker head gasket on, but we just replaced the top end of the motor and it would be a major pain in the butt to do it all over again. Perhaps I may wait for a year or two and do it right, I dont particularly care about having a super fast car. If i wanted that I wouldnt be driving an eta. Its just a project my friend and I would like to take on someday.
Thanks

[Jarvis]

I'm no expert either, but I thought the generally accepted figure was the M20s (at least 8.8:1 m20b25 'i's) could handle 12psi of boost on stock internals. If that's true, then only 7.5psi with the 9.0:1 eta should be safe.

[PeterCip]

I have 8.65 :1 compression with 9 pounds of boost. no problems.
You will be fine with 6 punds running into 9:1 compression. Buy maximum boost by corky bell. it will answer all your questions.
-pete

[EtaSport]

sounds good guys. Thanks for your info. I know that if im going to go to all the trouble of a turbo i might as well go big, but i am also going to use this thing everyday, with the intention of lots of miles. So i will probably use a T3 on a 524td manifold. Like i had mentioned.. my car isnt the fastest thing on the planet, and thats cool with me.
Thanks again

jon