The Stovebolt Site Forums The Shop Area Engine Shop Help !! manifold problems

Well, I finally fired the old girl up today after one heck of a fight. '54 engine in a '56 truck. Had to adapt the fan to get it closer, etc. New valve job on head and everything appeared to be square (head, manifold) but I have a terrible exhaust leak toward the front of the engine, so it looks like the manifold has to come back off. My question is on the sequence of the tightening of the manifold. My service manual says see fig 81, well 81 is the intake for a sbc..I have a 235 6-cylinder. When I put it together, I went from center to outside on an alternating pattern.Is this right?..If NOT...I need to know correct pattern and torque specs...TIA...I'm not real happy right now !

I would suspect that one of the alignment rings has cocked holding the manifold away.

Thanks for the advice Dave, just aggravated that I have to tear it apart again. It seems to be leaking on the front/bottom side

Another thought here, the head # is 3835913, the manifold # is 3835590 (I think, hard to read) were there different manifold configurations that may be causing me this problem ?

That is a 54/55 235 head (high pressure 235).

I think that is an earlier 235 intake code. There might be a date casting code on it.

I do not know how compatible that intake is on a later head. Does it bolt up? Do the alignment rings work on the intake and the head?

1950-62 235 manifolds bolt up exactly the same.

I suspect the alignment rings as I have experienced the same problem several times.

The problem comes in when an exhaust manifold has become warped up at each end over time(and most are). In many cases it is not possible to get the manifold started straight on the alignment rings with the two end studs in place.
I usually need to remove the end studs to install manifolds than I install bolts instead. A lot of times it is not possible to install anything in the end holes.
Do not try to pry down on the manifold once installed to get the end bolts in. That is a sure way to break the manifold.

Dave; The manifold seemed to go right in place when assembled with out any prying or force. Is it in my best interest to pull it all apart, check everything for square and go from there?. I do have another manifold here, maybe I should swap it out when I get the other one off..what do you suggest?

I would put a straight edge across the manifold once you have it off. The intake and exhaust may not be bolted together in line, or the exhaust ports may be eroded away enough so they are not flat.

You haven't said if your using alignment rings.if not it is difficult to get the gasket to seal but it can be done. I also had to get a intake and exhaust milled in order to get them true and seal.

Yes, the rings were installed, I'll get this thing off in a few days and report what I find....Thanks to everyones imput.

Got it FIXED ! Pretty sure pre68Dave had it right. I checked everything for square, which it was. Cleaned every bolt on wire wheel, also the alignment rings. Cleaned all gasket surfaces with wire-wheel on 4½" grinder and put it back together with new gasket...Fired her up and she's NOT leaking...
Thanks to all for your help.....

You might check the manifold warpage. I had to replace a manifold last year after removing it to put a fresh gasket on it. I took a piece string, pulled it tight, and aligned the string along the bottom of the inside of the ports. My manifold was so warped that I couldn't get it back on the engine with alignment rings in place.

Walt Williams
La Verkin, UT