Cutting Crossmember???
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
I believe there's a consensus that it's just plain easier to work on with the member cut. It may upset purists for you to do so, and I wouldn't chop it if it's a rare orig either, but it doesn't alter that fact.
Thread Starter
Burning Brakes
Joined: Feb 2007
Posts: 779
Likes: 0
From: San Bruno California
Hey bullshark, which of one of those vette has that removable crossmember? Does the flange you welded on hit the fiberglass floor. And what is the distance from the exhaust hole to the cut of the CM? Vetteguy112233 did an interesting one, he made a box that covered all 4 side of the crossmember. You slide the box to one side of the CM and take the removable piece out. Tony
Melting Slicks
Joined: Nov 2003
Posts: 2,668
Likes: 119
From: St. Charles Mo
CI 5 & 8 Veteran
Hey bullshark, which of one of those vette has that removable crossmember? Does the flange you welded on hit the fiberglass floor. And what is the distance from the exhaust hole to the cut of the CM? Vetteguy112233 did an interesting one, he made a box that covered all 4 side of the crossmember. You slide the box to one side of the CM and take the removable piece out. Tony
With the clearance I had between the fiberglass floorboard and the crossmember, I had to maintain a 0.5" flange dimension as shown on the drawing. The structural integrity of the crossmember using this approach is not comprimised. I had a couple of structural engineers where I work verify that for me.
I cut the crossmember at the center of the passenger and driver floorboard, but where you choose to do it is not critical. One of the beauties of this approach is that the crossmember is self aligning. I had the flanges water jet cut based on the OD of the crossmember. I then welded a flange on each end of the center section. I slid the other two flanges on the outer crossmember sections, bolted it up and tack welded them in place. Removed the center section and finish welding the outer flanges. It fit like a glove. Bullshark
Race Director
Joined: Jan 2000
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
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2017 C2 of Year Finalist
Mine is very similar to Bullsharks.
JIM
JIM
Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
when i installed the motor and trans on my 70 rebuild (also converted from th400 to muncie), the weight of the motor-trans would torque the cross member and drop the tail housing about 1". i just welded the cross member in place in the proper position.
with all the problems of driveshaft alignment, and many posts advising to raise the tailshaft to obtain correct angles between the trans and pinion, i didn't want any chance of the member twisting.
jeff
bullshark-really nice work!
with all the problems of driveshaft alignment, and many posts advising to raise the tailshaft to obtain correct angles between the trans and pinion, i didn't want any chance of the member twisting.
jeff
bullshark-really nice work!
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Racer
Joined: Jun 2004
Posts: 452
Likes: 0
From: Southern Md
I like the cross member mods done here and need to do one for my Tremec but how can I open up the holes for easier exhaust removal without compromising structural integrity.Any more pictures of that?. Thanks.
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
I cut my cross member years ago for my Tremec trans. Best thing to do as I have had the trans and exhaust off every year since then for other reasons. Makes removal a snap. I had my exhaust made with a slip fit right in front of the X memeber. I use a 4 inch wide S.S. band clamp to cut down on any leaks. It works very well and there is a small minor amount of leakage but nothing you can hear or detect. I just loosen the band clamp and slide the back half of the exhaust out. Then remove the X memeber and the front short pipe and I'm good to go. Takes about 15 minutes to have it all on the ground.
Le Mans Master
Joined: Jan 2007
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From: Peekskill NY
Melting Slicks
Joined: Nov 2003
Posts: 2,668
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From: St. Charles Mo
CI 5 & 8 Veteran
Yeh that's what I told my soon to be wife when she said she wanted 10. 
For those of you who keep your cars original.....there is really no need to make it removable. For those of you who have already done mods, then there is no reason not to. Just my humble opinion.
Bullshark
For those of you who keep your cars original.....there is really no need to make it removable. For those of you who have already done mods, then there is no reason not to. Just my humble opinion.
Bullshark
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
When I had the exhaust built I had them make a slip fit right in front of the X member. There is a short pipe off the header maybe 18 to 20 inches and this slips inside the pipe coming through the X member. I just looked for a picture and don't have one. Let me put the car on the lift and shoot one for you so you can see what I'm talking about.
Melting Slicks
Joined: Nov 2003
Posts: 2,668
Likes: 119
From: St. Charles Mo
CI 5 & 8 Veteran
Bullshark
oops, closer examination I see he did cut the crossmember......nice work.
Last edited by Bullshark; Mar 21, 2008 at 12:41 PM.
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
Here you go. My cross member job is not as pretty as Bullsharks but it works.
Exhaust band clamp
Here you can see the ball and socket joint which allows the right and left side to come apart and the rear of the X memeber.
Here is a shot from the front
Exhaust band clamp
Here you can see the ball and socket joint which allows the right and left side to come apart and the rear of the X memeber.
Here is a shot from the front
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
