New S52 Help

[ebg1223]

Recently acquired a fully caged 1995 M3 race-car. First BMW race car, very excited but need a little help.

About the car:
1995 BMW M3, unknown miles.
Raced for 7-8 years, but has been parked for at least the last 5. Driver money-shifted, motor was blown, and wasn't repaired.
Car is fully caged, racing LSD, racing clutch, new shifter, upgraded cooling system, baffled oil pan, and lots of other track-ready add-ons.
Car is OBD1 but previously had S52 with M50 manifold.
Only mods to the previous engine were sunbelt cams and corresponding ECU chip.

Plan:
We are looking to restore the car to be used as a reliable track car, not necessarily a race car. Our goal is something fun and reliable, but doesn't necessarily have to win races.

Question:
We are sourcing a new S52 for the car. Have identified 3 candidates and are having trouble deciding between them:

1. 1996 M3 Coupe Manual transmission. Engine has been tested and pulled from vehicle. 122k miles. 12 month warranty
2. 1998 M3 Sedan Automatic transmission. Engine has been tested and pulled from vehicle. 140k miles. 12 month warranty
3. 1998 M3 Manual transmission. Engine in vehicle, but junkyard refuses to run compression test. They claim it is still in the car and car runs well. only 108k miles. 90 day warranty.

Any advice? Which would you buy? They are all about the same price, including shipping to the shop.

Side question: would you install sunbelt cams given the goal of keeping car reliable. Is it worth it or are they problematic when used only on race track?

Thank you in advance.

[dcvee]

I'd take the 98 manual AND tell the shop you want the tranny too since they won't give a compression test. 200 bucks more.

I wouldn't install cams...yet. Get the car sorted. Have some fun. Then mod. Yes, even with cams these cars are more than reliable. This forum is a great source of information on what to do. Like the old saying goes; to finish first, you must first finish!

Don

[aeronaut]

Any of those engines could be great or a POS. With the engine out of the car, I'd be tempted to do the same thing to each one no matter what 'tests' the seller has done. I doubt any warranty past a few days is going to actually be defendable and useful. So, if you don't need a trans, I'd get the cheapest one. If you plan to keep the car, I'd replace/repair head gasket and VANOS while it's out of the car. And I'd have a hard decision on installing Sun Belt's now or later.

[bluptgm3]

I believe Sunbelt has closed, so no more support. The VaNos needs to have limited 'travel' with Sunbelt cams (and may require heavier springs.)


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[ebg1223]

Thanks for all your replies! Had an idea, ended up contacting the junkyards asking for VIN numbers on the engines. Ran each through carfax as if buying the vehicle used. Turns out both 98s had very poor service histories and many owners. The 96 had 1 owner since new and was totaled by insurance in a collision due to frame damage. Serviced on time at dealer and very reputable shop.

Don/dcvee: thanks for advice! I am going to hold off on cams for now. Learn the car.

aeronaut: Not sure I am going to keep the car. It has been sitting for a long time, so there are still lots of unknowns that we won't be able to figure out until it is running. Might also go S54 eventually, or if it turns into a big mess, part it out.

bluptgm3: thanks for tip on sunbelt. I think going to leave it stock for now, see what it is like.

[MauiM3Mania]

If you're unable to inspect the engines, it's a gamble. All things being equal, I'd go the auto, since it's likely not been money shifted.

[GG Emerican]

Thoughts on an LS swap? Or are you wanting to keep it stock?

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[eye145]

I was going to recommend the auto as they have no chance of money shift or over rev that would weaken the valves if they made contact. Also the auto trans would probably lived its life at a lower rpm than the other manual engines.
As far as the Sunbelt cams it depends if you are using the sport or race cams. The higher duration cams (280* and up) you have to know how to properly time them or use the vanos shim to limit travel. This applies to any of the larger cams wether its Schrick, VAC, Sunbelt or whom ever.
I would get the s52, refresh the entire cooling system, add oil pan baffle, replace what ever gaskets you can with in the budget working from the outside in. ie: valve cover gasket, oil pan gasket , oil filter housing gasket and lastly the head gasket. Throw some fresh plugs in it and go have fun....