new turbo build,part 1

[topcat 11]

As most of you know,I was the proud owner of a E28 M535iT.

And yes it was a fun vehicle to drive.With the little mods to the suspension it handled well and behaved

well in most situations.Engine was boosted to 15 psi and ran a comfortable 380HP with buckets of torque.

The car was rough in places,which didnt really worry me as I can do most repaires myself.

The main problem was when I had to get it certified (local garage would not put another WOF on it)

We put the thing on the hoist to give it the much needed pre-check.

I knew it had rust in the body,what i didnt know was,the chassis rails were in such bad condition.rust holes were forming just behind the cross member.the more we looked the more interesting evidence was noted that this body had been in as serious acccident at sometime in it life.

Could have spent the $$ to change a rail and fix the body,but from previous experiance,if it has rust,youve got problems for life.

Never mind.

So onto the next project.

Mate had a e34 525i body that had been in his possesion for a while.very basic vehicle,cloth interior,4 speed auto. does have AC schnitzer 17" wheels and body kit

While the e34 is heavier,they are a better engineered chassis,with less flex etc.

Also more upgradable parts available such as brakes,driveline parts and suspension etc

This vehicle is now stipped both inside and out.waiting for its need leather interior and engine

This time checked over for damage etc and seems to be a tidy jap import.

Now dont get me wrong,I'm not a fan of imports,but the price verses condition-it was a steal.

The easiest solution was to pull the lump out of the e28 and slip it into the e34.

This would have proved far more cost effective.But with a large shed full of old e23,e24 engines parts etc,

I decided that a fully rebuild with the best combination to make a 3660cc engine.

I had a 635csi awhile back,rusted beyond repair that was bought for $150.

Block is the early m90 block or the 'true' 3.5L engine,93.4mm bores

the engine looked okay,from the outside.It didnt look too good after i drained bout 20L of goo out of it.

head off-full of white frosting.Oh no what have I started

Filled the bores with CRC and left it to soak for a few days.

A week or so later with aid of a hammer and a block of wood,drove out the pistons.

3 came out easy- the others,had started to graft them selfs on to the bores.

Bores are scored/marked and pistons arnt the prettiest.interesting though-bores still had the hone markes from factory.With advise,it was decided to enlarge the pots and fit new pistons.not what I had banked.

Its been a few weeks now and the block has been tested for cracks etc.It came back 100%,so thats a relieve.

and the crank that I'll be using has also come back.cranks out of a e32 block 86mm throw. an e9 525 would be better, 88mm throw but where are they hiding out??think that this is the S38 combination of block and crank(?)

Had the crank shaved as pictured;lost 3.5KG in weight.Original weights round the 30KG.

Also crack tested;fell out of the passanger side of the van as I opened the door on to the concrete.

Pain.....then I heard of how Bugatti 'tested' their cranks-drop them from the 3rd story window,if it didnt shatter/bend/crack,fit into block and go racing.

Pistons have been ordered,will be 95mm forged alloy,flat tops as the compression has been calculated to be 9.3/1

useing the e34/e32 head.not ideal turbo numbers,but am planning not to run more then 10-12 psi of boost and not below 98 octane.Also with the higher compression,will have less lag etc,and with alittle head work should give good number when finished

http://www.not2fast.com/turbo/glossary/tur...torDutyCycle=75

some where i want to end up with number wise

Edited June 15, 2008 by topcat

[mr E34 11]

Good story, got a pix of the head with big valves? How did you fit 3 odd mm larger inlet valves, much alloy removed etc? Also, do you know why BMW switched to the 3430cc engine? Any advantage compared to older bore/stroke.

[topcat 11]

Good story, got a pix of the head with big valves? How did you fit 3 odd mm larger inlet valves, much alloy removed etc? Also, do you know why BMW switched to the 3430cc engine? Any advantage compared to older bore/stroke.

more info in part 2 soonish.a few tricks to that head job,not prepared to share info until i have hard data on flow advantages etc.yes lot of alloy removed.

older styled 3.5L setup had a 84mm crank, reved better,but had less torque

Edited June 15, 2008 by topcat

[tire 10]

I want a big hanger like yours!

Edited June 15, 2008 by tastic