392 cragar manifold doesnt fit blower

going through motor parts for my blown 392 build. ive noticed that my blower ( that appears to be a 6-71 weiand) has a different bolt pattern than my intake. the intake is a old cragar, with the burst panel in the front. the intake fits the heads perfect, and also fits the perimeter of the blower fine. just the bolt pattern does not line up. whats the deal?

thanks,
jason

 

Not sure about your Weiand huffer - but I am fairly certain the Cragar you describe will fil a Moneyham, Stock GMC Case, and a Bowers (I say this because a have a couple Early Cragars and I've tried all those blowers on them. Sounds like maybe Weiand made a goofy pattern case????

 

I've seen some manifolds like that modified for bigger blowers, ie 8/71

 

Kerry makes an interesting point - could you post a picture or two - it might help out a bit if we could peek at it.

 

Since he said it had a burst plate that made me think the previous owner was serious. Nobody who is truely serious about making hp with a blown engine runs the lowly 671. Somewhere I've got a pic of a modified manifold. I'll look for it

 

ill post some pics tonight
thanks

 

lets see if i did this right.

 

and some more

 

maybe this time

 

How many bolt holes are in the manifold? 4 or 8?. The 2 bosses on the right side bottom of the case and the polish job makes me think that isn't all wieand. I never messed with anything smaller than a 6-71 but I think a 4-71 only had 4 bolts. But I do know that the bolt pattern on a 6,8,10-71 is the same Seeing that you only have one stud in the manifold makes me think it is a 4-71 manifold. Pull the supercharger off and lets see a pic of the bottom of it and the manifold. JC

 

That case is a "stock" GMC case - as evidence by the cast in hanger tabs - that are normally machined (sawed) off for use on a 'car' engine. That tells me that it may have not been "built" by Weiand even though it has some Weiand ends plates on it. I'm not saying anything is wrong with using a stock jummy case - lots of blowers are set up usign those - the puzzling part is what doesn't fit???

That case ought to fit that intake. How far off are we talking?? Are those ears adding to the issue???

 

4-71's do have 4 bolts, but they are one rib shorter than a 6-71.

 

Hey, I've got a front cover just like that I'm gonna use on the digger.

Any chance you took a picture of the top of the manifold without the blower setting on it? Whoever had it before was serious as is evidenced by the holes drilled for port injectors. Did you switch from the burst panel to the Cragar popoff valve?

 

After another look at the manifold, there is no way its a 4-71 manifold, its been machined for port nozzles. So its been ran on fuel or alcohol. The 8 bolt pattern on a GMC case like that was used on 6-71 up to 112 and some old 14-71. We need more pics.

 

Kerry, I've seen several of those Cragar manifolds - all I've seen so far are machined for port nozzles - from the factory.

 

That manifold never had a bust panel on it. Only the original pop off. To put a burst panel on it you would have to machine the hole out and weld a burst panel mount on it. JC

 

Jason - if you wanna measure between the bolts - I can check it against what I have laying around.

 

there are 4 bolt holes down each side of the manifold and the blower. the two studs coming through are the only ones that line up.

 

stupid suggestion:
turn the manifold around so the pop off is to the rear

 

The blower could be assembled with the case backwards.

 

The Pop Off plate - should face the front as shown. I have a couple here to look at.

 

I have actually seen one that wasn't drilled for port injectors but I didin't have the $$$ at the time. Good thing actually because I've got a deal pending on an early Weiand Typhoon series manifold. This is the really short one that actually sets the blower off to one side slightly. The deal is waiting on me to scare up the dough again. I have my $$$ tied up getting the back and top hoops for the digger. I plan on sending the bucks after the next paycheck.





Sorry to hijack!

 

I think we have a winner.

 

ok guys i figured out the mystery. i went out to measure between the holes and well the blower has been assembled backwards. the snout is on the wrong end. the bolt pattern is different from side to side. turn it around and it fits. looks funny though with the pulley in the back. there is silicone around the bearing plates so i guess someone has had it apart.

 

Do you have enough meat in the manifold to punch in the 6 other holes you need?

 

Yep Yoyodyne - hit the nail on the head!!! It's a backwards assembled case!!!

EDIT: I posted this AFTER I read the updates - oops!!

Hey Kerry - I wasn't suggesting ALL the manifolds are machined for port injectors - just so far all the Cragar's I've seen have been factory machined - now granted that's only maybe a dozen manifolds - have you seen Cragar's like the one here - not drilled. I wonder if the drilling was an option that Cragar offered????

 

I'd have someone knowledgeable go through that blower. The tabs still being on the case and the backwards assembly suggest that the last guy to work on it wasn't an expert, to say the least.

BTW, neat looking coupe.

 

Yeah, it was an early one, before they started repopping them. Check this out. Not sure if they are still honoring this price but it's a deal these days.

http://www.sassyengines.com/newdiscountedparts.html

 

thanks for the help guys. i knew we would figure it out. so is there anything wrong with using this stock type blower? im just building a street car.

 

Just goes to show, don't ever take anything for granted. Crazy shit huh.