Well, I just completed my H.O. eta motor. Mostly been a secret since I really didnt know how it would turn out, but my e30 has been down for almost 3 weeks. So, what did I do?
tanked head, valve job with new seals, resurfaced exhaust manifold surface (all work done by previous owner, with this and the install I have the recipt for 1200 bucks).
installed m20b25 valve springs, opened intake and exhaust ports above eta spec, but below 'i', polished valves, chambers, and exhaust ports. drilled oil journals for cam lubrication, installed 274/274 eurosport cam and .060" oversized rocker eccentrics. Installed new rocker shaft to replace gouged unit (done by machine shop). ported intake manifold to match head. already have 325i throttle body port matched.
So, how is it? Its quicker, and noticably faster. Low end did not suffer at all, picked up a bit more go, but it really pulls harder in the higher rpm range. I can run it all the way up to 5 grand and it pulls from 1500 right up. I have a feeling it will make even more power over 5 grand, so I will have to find a chip to suit. I'm estimating the motor to be around 150hp right now with stock chip. I think it needs a better intake and exhaust set-up, so these things are on the way. It lopes like my 327 v8.
finishing touches (down the road): single mass flywheel, 3.25 rear diff, 325i exhaust, probably get the 325i intake, air filter w/heatshield, maybe larger afm, and engine software.
build cost tally- just under 400 out of pocket.
tanked head, valve job with new seals, resurfaced exhaust manifold surface (all work done by previous owner, with this and the install I have the recipt for 1200 bucks).
installed m20b25 valve springs, opened intake and exhaust ports above eta spec, but below 'i', polished valves, chambers, and exhaust ports. drilled oil journals for cam lubrication, installed 274/274 eurosport cam and .060" oversized rocker eccentrics. Installed new rocker shaft to replace gouged unit (done by machine shop). ported intake manifold to match head. already have 325i throttle body port matched.
So, how is it? Its quicker, and noticably faster. Low end did not suffer at all, picked up a bit more go, but it really pulls harder in the higher rpm range. I can run it all the way up to 5 grand and it pulls from 1500 right up. I have a feeling it will make even more power over 5 grand, so I will have to find a chip to suit. I'm estimating the motor to be around 150hp right now with stock chip. I think it needs a better intake and exhaust set-up, so these things are on the way. It lopes like my 327 v8.
finishing touches (down the road): single mass flywheel, 3.25 rear diff, 325i exhaust, probably get the 325i intake, air filter w/heatshield, maybe larger afm, and engine software.
build cost tally- just under 400 out of pocket.
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