Please Explain..........

dj10

dj10

New member
How do you have a E36 325 that is suppose to be legal for SCCA ITS when you have a .040 engine?
1. BMW only makes rings for a .020 bore.
2. NO ONE that I have found in North America makes rings of the same size that BMW makes. Specifically the oil ring which is 2mm thick. All the manufactures I spoke to make them 2.5 or 2.8mm.
I hope someone can explain this I would like to know who the manufacturer of the legal rings is.
dj
 
Originally posted by Andy Bettencourt:
This is a great question that could be asked of Bimmerworld, Rebello or Sunbelt. They should know.

Or maybe (shocker!) a BMW owner will provide some data.

AB
Click to expand...
Andy,
I am a E36 owner and I did supply what data I had. So from what info I have gathered, if you have a BMW E36 2.5L with a .040 overbored engine you have to be illegal. Or am I missing something?
smile.gif

dj
 
Can't believe the rules nerds haven't jumped all over this one. I won't quote the GCR because I can't from memory, but is memory serves me you can use aftermarket pistons up to .040" overbore if they are the same weight/configuration. In addition, if you specify a ring size to someone like Ross or JE, they will obtain for you that ring size. The GCR does not require OEM parts!!! Chuck
 
Originally posted by dj10:
How do you have a E36 325 that is suppose to be legal for SCCA ITS when you have a .040 engine?

I hope someone can explain this I would like to know who the manufacturer of the legal rings is.
dj
Click to expand...

Read the GCR, it's full of great information. And as for you last question, give Wiseco a call.
 
DJ, you're missing something: non-OEM pistons are legal, and you can get rings and pistons made in whatever configuration you want. All it takes is Benjamins. - GA

[This message has been edited by GregAmy (edited June 24, 2005).]
 
Originally posted by GregAmy:
DJ, you're missing something: non-OEM pistons are legal, and you can get rings and pistons made in whatever configuration you want. All it takes is Benjamins. - GA

[This message has been edited by GregAmy (edited June 24, 2005).]
Click to expand...

Don't the rules requires alternate pistons to be the same dimensionally? This would mean the ring packages would have to be the same in width, spacing, arrangement on the pistons, etc. So I guess what dj10 is getting at is that unless the replacement pistons use the OEM ring package dimensions (with the unusual oil ring size), they are illegal.

Hmmm.....

MC

------------------
Mark Coffin
#14 GP BSI Racing/Action Digital/Airborn Coatings/Krispy Kreme VW Scirocco

[This message has been edited by racer14itc (edited June 24, 2005).]
 
So I guess what dj10 is getting at is that unless the replacement pistons use the OEM ring package dimensions (with the unusual oil ring size), they are illegal.

Hmmm.....

MC

[/B][/QUOTE]
You are exactly correct!!! Matching pistons is not a problem, but matching the BMW factory rings is. And if the rings (all the rings) aren't identical to the BMW Factory rings then the entire .040 bore is illegal! Read the rules.
dj
 
Originally posted by Bruce Shafer:
Read the GCR, it's full of great information. And as for you last question, give Wiseco a call.
Click to expand...
Bruce,
I have called Wiseco and that is why my engine is not bored to 1mm over. The oil ring they (or thier ring manufactures) have are not the same thickness as BMW Factory rings. And no one in North America makes a 2mm oil ring. I know because I called all of them. Gheez I hate to be reduntant.
Damn I enjoy a good dialog.
smile.gif


dj
 
I don't think you did call Wiseco, because if you had, you would find out that they will make any piston and any ring as long as a specification or example is provided.

Did you find anything else wrong with the ad? How about that engine stay rod?
tongue.gif
 
I don't think you did call Wiseco

Anyone that knows me, will tell you I won't lie or cheat you. If I'm wrong I'll admit it. I checked with SCCA Tech and they said it was illegal. I'll call them again need be just to double check.
Piston rings are unrestricted means any manufacture can produce them as long as they are the same thickness.
dj
 
Originally posted by robits325is:
ITCS section j pages 6 & 7: "piston rings are unrestricted"
Click to expand...

Nice try, but your "unrestricted piston rings" better fit in the OEM-sized and spaced ring grooves in your pistons!! Otherwise it's cheating, plain and simple.

MC
 
Originally posted by racer14itc:
Nice try, but your "unrestricted piston rings" better fit in the OEM-sized and spaced ring grooves in your pistons!! Otherwise it's cheating, plain and simple.

MC
Click to expand...

It isn't a nice try its the rule.
 
Sort of Rob.

"Engines may be bored to a maximum of .040 inch over standard bore size. Factory oversize replacement pistons or their exact equivalent shall be used. Cast or forged equivalent pistons shall provide the same dome/dish/valvle relief configuration, ring thickness and spacing, pin height relationship, weight, and compression ratio as factory oversize pistons. Piston rings are unrestricted."

So your .040 pistons are exactly like factory overbore pistons...the ring size is dicatated by those pistons...the manufacturer and material may be unrestricted, but the size isn't...it's chosen for you.

AB

------------------
Andy Bettencourt
New England Region, R188967
www.flatout-motorsports.com
 
I also disagree Rob. While aftermarket pistons are legal, they must conform to all factory dimensions (except for the allowed overbore). Rings are also free, but that allowance does not also allow modifications to other parts to fit them.

If you're running aftermarket pistons, fine. If you're running rings that are thinner or thicker than stock, you're seriously illegal. - GA
 
Originally posted by robits325is:
I only quoted the rule as written in the GCR. It is certainly possible for someone to make a .040 piston that is legal.
Click to expand...

Turner has M50 .040 exact replacment pistons listed on his website.

http://www.turnermotorsport.com/html/detai...CT_ID=921644061

I would also venture a guess that .040 Mahle pistons are available somewhere. I was able obtain several sets of these for my M20 E30 motor. I was also told that these didn't exist. BMW has made a lot more M50's so the market is there.

Hopefully this will end this thread which had the premise that any .040 M50 motor has to be illegal because one person claims (dubiously) that they were not able to source the correct rings.




[This message has been edited by Bruce Shafer (edited June 26, 2005).]
 
Last post on this subject!
If any of you race a E36 325 with a .040 bore and you protest them, don't worry, they will be disqualified. The rings are illegal. If you don't believe me do your own research. If you have a .040 engine you have a large paper weight or an illegal motor.
Its time we police our own ranks and keep things fair to everyone.
 
You can call up any number of manufacturers and have custom pistons and rings made...almost had to do it yesterday when a ring broke on the S50B32 we are putting in my father's M3. So you need a 2mm ring? Call up a custom comapany and order them.

Just because Wiseco doesn't tell you they are available when you call their order line doesn't mean that they can't be made if you send them a nice fat check.

Originally posted by dj10:
Last post on this subject!
If any of you race a E36 325 with a .040 bore and you protest them, don't worry, they will be disqualified. The rings are illegal.
Click to expand...



[This message has been edited by Bryan Watts (edited June 28, 2005).]
 
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