Bellhousing Clarification

I have a 6.3 spec 8 1/8" bellhousing now, I used to use it with a dual disc clutch, I now have a triple disc clutch, can this bellhousing be used? Or do I have to go to a different spec. I looked on the SFI website and it indicates that 6.3 is ok in blown alcohol with a 2 disc max, fair enough but which spec do I go by for a blown alcohol triple disc clutch?

I was going to send my old one back for recert but it could be a waste if I need a new one.

Thanks
Corey

 

Legally? I couldn't tell you, up to sanctioning body I would guess.

6.2 is the spec you'd need to comply... The rating is based on the total weight, linear speed and horsepower of potentially exploding material and the can's ability to contain it properly. Typically the sanctioning body is the final rule, but if it's NHRA, they pretty much follow SFI specs.

 

Thats what I thought, I may have shot myself in the foot a bit. All the 6.2 spec housings don't have a starter pocket (that I have seen). I'm a door car and need a block starter.

Any idea if there are 6.2 spec housings with starter pockets? I'm going to make a few calls but I'll take any advice that can be had.

Thanks

 

SFI Specifications for Bellhousings are as follows:

6.1 Spec: For use on Naturally Aspirated vehicles ONLY; running SFI spec 1.1 and 1.2 two disk clutch assemblies, or SFI spec 1.1 and 1.2 three disk clutch assemblies Commonly, Pro Stock vehicles will run this bellhousing

6.3 Spec: For use on Naturally aspirated cars running SFI 1.2 two disk or more clutch assemblies, or Supercharged/Nitrous injected vehicles running SFI 1.1, 1.2, and 1.4 Spec clutch assemblies, with a two disk maximum. Commonly, Pro Mod vehicles will run this bellhousing

6.2 Spec: For use on any vehicles running SFI 1.3 and 1.4 spec clutch assemblies. Commonly, Top Fuel and Top Alcohol vehicles will run this bellhousing

 

Thanks I actually read that a bunch of times and came here for final clarification. As I mentioned its a 6.2 with starter pocket that I need and I can't seem to find one. It seems they can't make them like that and meet the 6.2 spec.

 

NHRA lets SFI 6.2 and 6.3 in Pro Mod. Most likely for the reason you have just stated. I don't believe starter pockets are allowed in 6.2 cans..

 

Ok, one more question then. There has to be Promods with triple discs clutches out there correct? (i think i know the answer but I would profer it from a professional)

 

You would be correct. They allow 3-disc with a max diameter of 11" and 4-disc with a max of 8".

 

Thanks for the info, it seems if you read the rules to the "letter" then a 6.3 would not be legal in promod but yet there are promods that self start and have triple disc clutches so the rules must be relaxed in that respect (like you said "its up to the sanctioning body")

Thanks again
Corey

 

Will a triple fit in an 8-1/8 can or do you need an 8-5/8 ?

 

My Crower pro sportsman triple just fits in my 8 1/8" and with a Lenco short TOB it works perfect.

 

8 1/8 is a little tight when you go to adjust the clutch. Make sure you use the short throwout bearing like mentioned above and that you have enough free play in your linkage situation. If you don't have enough free play the throwout bearing will prevent the fingers from fully engaging.

 

My thoughts are the same. If needed, I have a very nice 8-5/8 Ti can for sale. Thanks.