S50B30US NA rebuild for track car

[bimmerboy318]

Speaking of weight... My builder said that each piston /rod combo was 55 grams lighter than stock. So that's 330 grams less weight in the piston rod combo and they took 330gram off the crank to balance. That's a total of 660 grams or 1.45lbs less rotating mass!

As usual, Scotch was right. I assumed that they removed 330grams off the crank to balance. The balancing article I read was for a V8. Pistons & rods were balanced to each other and the crank balanced by itself. Very little was removed from the crank itself. So only 0.725lbs weight savings.

[BlackHawkRacing]

This was a fun read. Sub'd.

[bimmerboy318]

Finally picked up my motor. My builder only charged me $300 in assembly labor. My engine builder... he's actually an HPDE acquaintance. Was talking with some guys at the track asking where my e36 was (brought my Miata). One story lead to another so I figured I'd let him build the motor. Said he "moonlights" at an engine shop. Ok cool, whatever!

When I dropped off the motor, I never went in the shop, just outside the garage door. But when I picked it up, the first thing I see is this V12 Ferrari motor that goes in a 60s GT 250 (don't those go for $1mil at the big auctions?). Turns out this shop was the go to place for vintage Ferrari racing before all the cars became collectible.

54605835-F2B3-459C-976B-709CBE005472 by D S, on Flickr

After a brief tour of the shop, turns out, this shop was the official engine supplier for Noble up to the M600. M600 had the V8 Volvo turbo charged motors. Complete with engine and chassis dyno. Motors are all built in the UK now.

So needless to say I was shocked. They primarily do Sprint cars now. One guy was buttoning up a 400hp K24 with dry sump for a Midget. Motor Kraft in Noblesville, IN is the name of the shop.

40AB18F8-6E94-4CA8-8C47-A1E9AD73D8BC by D S, on Flickr

59DADEE3-96A6-40FB-AE4F-F66932D143EA by D S, on Flickr

094182D4-CBFA-4D94-A814-215F2ADAF374 by D S, on Flickr

FF1BA18F-9123-4794-BE96-B3E1E626D7C9 by D S, on Flickr

822628C6-40DC-4AC0-AF0A-422466A23D5F by D S, on Flickr

FD5C9265-4CEA-4D37-A65D-EDF36D65DC80 by D S, on Flickr

3C7BE4BE-6DF7-4B12-9B42-4C42027DB4ED by D S, on Flickr

29F36CB7-477F-4879-A73C-999AFE628946 by D S, on Flickr

69973AAD-93BD-48D3-8CDD-2E1B657B13C0 by D S, on Flickr

4224DCD2-C646-47E1-922D-D81B495530D2 by D S, on Flickr

EFCAF39B-02AC-40D8-BCC5-E99694D0669D by D S, on Flickr

1DD97336-7B7B-4043-88A1-FA8BF4ECF08F by D S, on Flickr

[bimmerboy318]

Some notes I'll add here:

I was originally going to paint the outside flat black... but the original paint looks great. It's just the spots that never had any paint rusted a little. I think I'm just going to leave it unless someone gives me some compelling reason to paint it.

I see where some very mild seams in the head casting was removed... that'll be good for 1hp!

Head was decked .010" but when I measure with calipers I get 5.504-5.505". 140mm is 5.512". The old head was just skimmed and it measures 5.510". So I think the calipers are accurate enough to prove the head doesn't have a ton of material removed.

I couldn't find any evidence of any material removed from the big end of the rod after balancing. So maybe they were fine. The small end and wrist pin I can't see when assembled. I do see where they took a little material off the crank to balance.

[ScotcH]

Score on the engine builder! Looks like a nice job for sure. Shame to only run that with stock cams

I like the high heat aluminum paint. It makes the block clean looking, plus it's easy to stop oil leaks on the silver (vs black).

[aeronaut]

Looks like an awesome shop! Any shop with a floor that clean, that also does real work, gets a thumbs up!

And yea, cam that bitch!

[bimmerboy318]

Well, the only photo in there shop was the Ferrari motor. All the S50 motor pics were my garage. Just great, first how did my engine bay get so clean now how do I keep my garage floor so clean. If you must know, simple green and a mop. I grew up with sweep and mop every night when you’re done working... not when the project is done... every time you’re done working.

[GrifM3]

Well, the only photo in there shop was the Ferrari motor. All the S50 motor pics were my garage. Just great, first how did my engine bay get so clean now how do I keep my garage floor so clean. If you must know, simple green and a mop. I grew up with sweep and mop every night when you’re done working... not when the project is done... every time you’re done working.

I wish my garage floor was that clean. Oh . . . and needs cams.

[aeronaut]

Well, the only photo in there shop was the Ferrari motor. All the S50 motor pics were my garage. Just great, first how did my engine bay get so clean now how do I keep my garage floor so clean. If you must know, simple green and a mop. I grew up with sweep and mop every night when you’re done working... not when the project is done... every time you’re done working.

I sense a trend.

[bimmerboy318]

This is as far as I got today. I also checked piston to valve clearance via someguy2800’s video. The intake cam can sweep 30deg before it hits. That’s suppose to equate to 1.75mm of clearance. The exhaust cam I can sweep 53deg before it hits. But I don’t think it ever hit the piston in the respective bore like the intake. I think it cleared it completely and a different cylinder made contact. According to someguy2800, the exhaust cam is usually not an issue. This also tells me that I blew my motor because I reused 160k valve springs and a slight over rev cause is to float. A true money shift usually bends all the exhaust valves.

Also saw the valve job... pretty nice. Never seen the seat have a different matte colored stripe before, maybe from lapping? Apparently they still lap the seat after a valve job. I also see the back cut on the valve... hopefully flows better.

35C24DAD-F849-4560-886B-B60836F74F68 by D S, on Flickr

A582FF57-9D27-4B74-937F-07C9665B2A1A by D S, on Flickr

69AD769C-F0B2-4F9B-B8EB-C520C3DD8E78 by D S, on Flickr

[bimmerboy318]

So to comment on all of the “needs cams” comments. Primarily it’s because I don’t want to spend the money and can upgrade later.

But after checking piston to valve clearance, Schrick 264/256 and 276/270 have lifts of 11.2mm on the intake. That’s 1.0mm more than the stock 10.2mm intake lift. The rule of thumb is 1mm clearance. So either cam actually only gives 0.75mm with the more aggressive cam holding that lift longer and needing to be degreed to check.

For me, it’s not worth the 1mm reduction in clearance unless the pistons had deeper reliefs. These JEs have the same relief depth as stock.

Likely the milder Schricks work on the bare minimum of clearance. The more aggressive Schricks would either need a Vanos shim (as posted by Vac and Achilles on their purchase page) or start with a 2-4deg retard. If I ever do decide to upgrade, a call to Mino with my engine blueprint specs and I’m sure he could sell me what I need along with the Vanos shim.

All this playing with cams is what I don’t want to do. Yes, motor deserves cams! Maybe one day...

[GrifM3]

IIRC the Sunbelts Stg IIs do not increase the lift, just the duration. And I believe there is a limiting spacer on the intake cam. I modeled my build after fsmtnbiker's. Go here and read the progression of his engine mods with the respective dyno sheets, starting at post #528. https://www.bimmerforums.com/forum/s...Library/page22

Post #538 is very similar to my build, but has an Epic off the shelf tune.

[ScotcH]

IIRC the Sunbelts Stg IIs do not increase the lift, just the duration. And I believe there is a limiting spacer on the intake cam. I modeled my build after fsmtnbiker's. Go here and read the progression of his engine mods with the respective dyno sheets, starting at post #528. https://www.bimmerforums.com/forum/s...Library/page22

Post #538 is very similar to my build, but has an Epic off the shelf tune.

They absolutely increase lift. 11.2mm in the intake

[aeronaut]

So to comment on all of the “needs cams” comments. Primarily it’s because I don’t want to spend the money and can upgrade later.

But after checking piston to valve clearance, Schrick 264/256 and 276/270 have lifts of 11.2mm on the intake. That’s 1.0mm more than the stock 10.2mm intake lift. The rule of thumb is 1mm clearance. So either cam actually only gives 0.75mm with the more aggressive cam holding that lift longer and needing to be degreed to check.

For me, it’s not worth the 1mm reduction in clearance unless the pistons had deeper reliefs. These JEs have the same relief depth as stock.

Likely the milder Schricks work on the bare minimum of clearance. The more aggressive Schricks would either need a Vanos shim (as posted by Vac and Achilles on their purchase page) or start with a 2-4deg retard. If I ever do decide to upgrade, a call to Mino with my engine blueprint specs and I’m sure he could sell me what I need along with the Vanos shim.

All this playing with cams is what I don’t want to do. Yes, motor deserves cams! Maybe one day...

But, min valve/piston clearance doesn't happen at max cam lift, correct? So, I don't think you'll decrease piston/valve clearance by 1mm if cams have 1mm higher lift. Duration matters too. My research on the 276/270 cams were that you had to check clearances, but "usually" they would check fine.

[GrifM3]

They absolutely increase lift. 11.2mm in the intake

Thanks ScotcH, I stand corrected. It's probably been 5 years since I've gotten into the details. Either way, I've been very happy with their performance.

[Talperian]

So to comment on all of the “needs cams” comments. Primarily it’s because I don’t want to spend the money and can upgrade later.

But after checking piston to valve clearance, Schrick 264/256 and 276/270 have lifts of 11.2mm on the intake. That’s 1.0mm more than the stock 10.2mm intake lift. The rule of thumb is 1mm clearance. So either cam actually only gives 0.75mm with the more aggressive cam holding that lift longer and needing to be degreed to check.

For me, it’s not worth the 1mm reduction in clearance unless the pistons had deeper reliefs. These JEs have the same relief depth as stock.

Likely the milder Schricks work on the bare minimum of clearance. The more aggressive Schricks would either need a Vanos shim (as posted by Vac and Achilles on their purchase page) or start with a 2-4deg retard. If I ever do decide to upgrade, a call to Mino with my engine blueprint specs and I’m sure he could sell me what I need along with the Vanos shim.

All this playing with cams is what I don’t want to do. Yes, motor deserves cams! Maybe one day...

Playing with cams is where power is made.

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[tiMASTER]

Clearance checking is kinda like herding cats. Since the pistons are moving up and down while simultaneously the valves are opening and closing- and then- add variable cam timing and a dash of float for good measure.

Single cams are fun; dual cams are frustrating; variable cams are science projects.

Cuz rolling it over on an engine stand, ice cold, is not exactly the same as launching an E36 into low earth orbit on that rise at 7000rpm. Stuff happens. So you cut deeper valve notches and hope for the best. Poor decisions usually show up pretty early.

And I agree the old, worn out springs did you no favors on the old motor.

[bimmerboy318]

Playing with cams is where power is made.

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So then we also need to factor in the cost of tuning. Cams $1500. And I would think $500-700 for dyno time assuming you only pop the valve cover off once adjust cams while strapped to dyno.

[aeronaut]

So then we also need to factor in the cost of tuning. Cams $1500. And I would think $500-700 for dyno time assuming you only pop the valve cover off once adjust cams while strapped to dyno.

Oh, you want cheap power?

22.jpg

[bimmerboy318]

I priced a V8 swap and it wasn’t pretty. I just want an HPDE that can hold up to repeat abuse. I think the E36 and stock-ish S50 fit the bill so long as my valve springs keep up and I don’t money shift it. I have a Miata NB as a a back-up and an F80 track only car that my wife primarily drives because it doesn’t have a 3rd pedal.

[Talperian]

So then we also need to factor in the cost of tuning. Cams $1500. And I would think $500-700 for dyno time assuming you only pop the valve cover off once adjust cams while strapped to dyno.

It's not cheap, that is for sure.

I forget sometimes that others pay full retail from big name vendors for the same parts they can source for cheaper elsewhere.

I also sometimes forget others are on stock ecu and/or can't tune there car themselves.

Carry on!

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[aeronaut]

We're just yankin with you. We all have our pain limits when it comes to mod cost. I think we've all learned the lesson to buy the best you can now rather than buying the cheapest twice. But in this case, delaying cams isn't a bad money decision. The forums love spending other peoples money.

[Talperian]

We're just yankin with you. We all have our pain limits when it comes to mod cost. I think we've all learned the lesson to buy the best you can now rather than buying the cheapest twice. But in this case, delaying cams isn't a bad money decision. The forums love spending other peoples money.

Oh I know. It all sounds so easy when it's other peoples builds/money right?

I am definitely not an advocate of cheap parts...do it once, do it right.



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[bimmerboy318]

No worries gents! I love talking mods and cars. Even if I had the money... it's getting it right after you spent all that money that worries me the most. And trust me... I worry enough that this is going to well come Spring.

[ScotcH]

No worries gents! I love talking mods and cars. Even if I had the money... it's getting it right after you spent all that money that worries me the most. And trust me... I worry enough that this is going to well come Spring.

Yeah, you just get over that fear of shit going wrong at some point. I'm not proud of this, but we went through 13 head gaskets in one season ... until we figures out the issue for good, lol We've also done a ring job at the track using a tin can as a ring compressor and scotchbrite on the cylinder wall (Montreal F1 ... wasn't going to miss that!), plus any number stupid fixes to get the car back out. Budget unfortunately is always the fun killer These days, the car is sorted out pretty much, but now the tire costs are killing us (once you go to Pirelli or Michelin slicks, it's just no longer fun on anything else dammit!)