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Help me build a plan for rebuilding my engine...


KFunk
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After a scare the other day, I think my headgasket is OK for now, but the rings are well past worn anyways... I always get lots of smoke on acceleration, and compression is between 100 to 115 on all 4 cylinders. It still feels really strong, and I'm sure it'll still propel itself a while longer, but I'm gonna start slowly amassing parts to tear it down and rebuild it right by next winter. I think I can save a lot of money if I just slowly grab things as they appear on the FAQ classifieds or ebay. I've done some light rebuilds on small engines/motorcycles before, helped with a few car engine rebuilds, but never done a full rebuild on a car before myself.

Background: It's probably got 200K to 300K on the original bottom end. I replaced the oil pump and timing chain a couple years ago, but I presume bearings/pistons are original. I had the head off 5 years ago, replaced a couple bad rockers, planed it a lot (it was warped bad, needed 10 ton press to get rocker shafts out). I've got 40 DCOEs on it, which I love, but I know they're limited by the stock cam. I do love the torque, though. I've got a 3.91 LSD that I'll stick with, and a 4-speed, which I'd like to change someday but that's not a priority.

What I want: I'm gonna keep the original block. I want it to be a cheap, reliable workhorse that'll allow me to get some more power and torque from the DCOE 40s. I don't want a peaky power band that you have to rev to get to it. I love bottom end torque from the 2002, and really don't enjoy engines like the M42. I also need it fairly streetable and relaxed. I enjoy autocrosses and trackdays quite a bit, but street driving is my priority now. Of course though, I'm currently perfectly fine with DCOE 40s w/4-speed and 3.90, and full poly bushings, for everyday use and highway driving. Decent mileage would be good, though.

What I'm thinking: I should just get a freshly rebuilt head somewhere, or get a good rebuildable one and have a three angle valve job and stuff done. Should I stick with an E12? Or would another head be fine? Would 112 or E21 offer any pros or cons? I've got an electric fuel pump, and don't care about fuel pump mounting.

Cam- I'm thinking a 284 would be a good balance, is that right? I'd hopefully get a boost in power without having to rev too high or idle like crap. I still want to spin the tires whenever I want.

headgasket- Cometic or regular headgasket set? I dunno...

Pistons- Should probably get new ones, maybe 9.5:1? Any preferences?

Block- It needs honed at least, I bet. Last time I had the head off 5 years ago, the cylinder walls felt a bit rough. I figure when I do tear it down, I'll send only the block to Oak Machine in Logan, OH and and have them take care of the block. Should I go ahead and have it bored? I'll probably have to wait on ordering rings and bearings until I tear it down and look it over.

Bearings- Not much experience doing these myself. I should probably get learning how to use plastigage and such...

Other stuff- I might keep the oil pump and timing chain. They're fairly new and haven't given me any problems. I might go ahead and get a new tensioner, rails, and oil pump chain. I might ge theadbolts too. I replaced them last time, and arguably they should be good, but they've had a tendency of backing out just slightly on me... might be safe to get new ones.

Clutch- Through 5 years of serious abuse, it's never given me a problem, but it has an unknown history, and I'll be in there anyways... maybe I should go ahead and get a new one.

Any thoughts? I could be pretty dumb when it comes to most of this...

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I'm very happy with my 284 Schrick cam...nice midrange power boost, decent idle (once I get the dizzy playing nicely with the rest of the engine) and it should help the DCOEs--not as much as a 292, but you'll notice the difference without the lumpy idle.

I also installed 9.5 pistons--they do fine on mid-grade gas without having to retard the spark at all.

Your oil pump is probably OK--my 69 with 223k miles still has 50-60 psi warm at highway speeds on 20W-50 oil. And you know you can use an E21 oil pump by swapping the pickup with one from an '02 pump. I scored a brand new E21 oil pump for $75 on closeout and swapped pickups.

We have a very good machine shop here in Beavercreek (Performance Clinic)--they build a lot of race engines and have done the machine work on my engines to my satisfaction--they've also saved two damaged cylinder heads for me.

What you're doing--picking up parts as you find good deals--was exactly what I did--except I started about 1994 and rebuilt my engine in 2006! You just have to be patient...Now I'm accumulating parts for the eventual rebuild on my '69...

cheers

mike

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I have brand new e12 Ireland 90mm 9.5-1 pistons and Ireland 284 re-grind. This was going to be used in a megasquirt setup.

I haven't had issues with e12 heads but if money permits I suggest looking for a later casting head. 80's on up. 9.5-1 cr is a good start using pump gas and a tii dizzy. Anything above that will require ignition upgrades. I'd also consider building up the head using SS valves, HD rocker arms, higher rate valve springs (depending on the cam you plan on running) and port matching the head is also a good idea. Depending on what you want to do the head will end up costing you a bit.

If you have good oil pump than that'll save you some money. But get new chain and gear.

If you have other questions just let me know.

Dracoruno@gmail.com

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Thanks for the help guys. I don't know I'm gonna resist not rushing into it, but I'll have to try.

What's up with these pistons? http://cgi.ebay.com/ebaymotors/MaxSil-Piston-Kit-BMW-E10-2002tii-1968-1976-M10-_W0QQcmdZViewItemQQfitsZMakeQ3aBMWQQhashZitem564116a352QQitemZ370459190098QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

They're real pretty, but I don't like trusting ebay, and I don't see a comp. ratio anywhere...

are these more reasonable? http://store.nexternal.com/shared/StoreFront/default.asp?CS=ireland&StoreType=BtoC&Count1=655620753&Count2=572761178

I should probably wait until I pick out a head before selecting pistons though...

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I just did a complete rebuild a few months ago. I used IE 9.5 pistons(work fine on 93 with no issues)284 cam. Car has tons of pwoer

BEST money spent was getting my distrubutor completely rebuilt by Advance Distributors. they converted it from vacuum to all mechanical and also installed a Crane 700 optical ignition in it. I can not express enough how much this dist has helped my car from constant even, smooth idle to super smooth revs throughout the power band

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skip the 284..go with a 292 with those dcoe 40's. you will not be sorry. plenty of tq and NO lumpy idle.

here is my 9.5:1, 292 shrick, ported head, xr700, mech dizzy and DCOE45's with 38MM main venturi's! smooth idle. engine was not even full warmed up.

i don't recommend 38mm venturi's for street though. stick with 32 if you want tq. 34 for more around town fun.

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skip the 284..go with a 292 with those dcoe 40's. you will not be sorry. plenty of tq and NO lumpy idle.

here is my 9.5:1, 292 shrick, ported head, xr700, mech dizzy and DCOE45's with 38MM main venturi's! smooth idle. engine was not even full warmed up.

i don't recommend 38mm venturi's for street though. stick with 32 if you want tq. 34 for more around town fun.

-we wish JB a merry christmas, we wish JB a merry christmas...

Kevin, I will be following your progress.. maybe do a blog on your trek to a budget rebuild?

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skip the 284..go with a 292 with those dcoe 40's. you will not be sorry. plenty of tq and NO lumpy idle.

here is my 9.5:1, 292 shrick, ported head, xr700, mech dizzy and DCOE45's with 38MM main venturi's! smooth idle. engine was not even full warmed up.

That is very tempting. Any ideas where I can find dyno charts that might compare the three types of cams? I'll try to search some on it later....

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don't be afraid of a 292. it is internet myth that it is "peaky" or "lumpy". it is not that different from a 284...just that little bit better all around. to me it just ain't worth putting anything less in a street M10 if you already have DCOE's. you can tune the engine power band easily by using different main venturi's in the DCOE's. smaller for economy and lower rpm hp, bigger for way more fun and higher peak hp. that is the beauty of the DCOE's....they are so flexible and easy to tune to what you want to do.

you also have that 3.91 going for you. you may have found this already, but here is mine with a 3.91. this was run with the dcoe45's. smaller chokes would have been better for auto-x.

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