Converting from smallblock to big block
Melting Slicks
Joined: Jan 2006
Posts: 3,028
Likes: 2
From: North NJ
Originally Posted by pef427
Thanks for the compliment but I think it has a little room for improvement. I honestly believe it is strong enough. But, I saw how 427Hotrod did his and it looked stronger. He cut the center out and after fabricating his new center section for the tranny he welded plates on each end and then welded matching plates on the frame section and drilled/bolted them together.
I may have to let that be a winter project...wait, we don't really have a winter in Southeast Texas, so I get to keep driving!!!
-p
I may have to let that be a winter project...wait, we don't really have a winter in Southeast Texas, so I get to keep driving!!!
-p
Here is a past thread that TopGun hooked me up in my other trany x-member thread....http://forums.corvetteforum.com/show...1505590&page=2
Here's an 82 bolt in for sale...http://cgi.ebay.com/ebaymotors/Trans...spagenameZWD1V
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by Yellow73SB
Whew good thing im back before you posted this. One less alais im accused of being
Personally I think you're an okay guy, just from what I've seen, ans a lot of people backed you up when it all hit the fan a few weeks ago. But you have to admit, that the alias accusal is called for and expected.
I like the idea of the two piece cross member like shown above. It's a simple design, supportive, yet easy to remove when working on the trans.
HOOK-EM HORNS
Joined: Aug 2006
Posts: 3,517
Likes: 842
From: Port Aransas, Texas Tx
St. Jude Donor '08
When the time come's that I have to redo my clutch with the tremec 5 speed I am going to cut it out.
I have a cross member from a 78 auto. I will bolt it up like the automatic.
I have a cross member from a 78 auto. I will bolt it up like the automatic.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by TEXASRANGER
When the time come's that I have to redo my clutch with the tremec 5 speed I am going to cut it out.
I have a cross member from a 78 auto. I will bolt it up like the automatic.
I have a cross member from a 78 auto. I will bolt it up like the automatic.
I wonder what it woudl take to make a trick member out of heavy tubing, and a pin-in style of holding it. Two large pin-bolts on either side, so it rests on perches, held tight by pins slid through, and retaining nuts. That'd be VERY easy.
Melting Slicks
Joined: Dec 2005
Posts: 2,441
Likes: 0
Bowtie Overdrives already has a Vette crossmember made from tubing.
http://www.bowtieoverdrives.com/cata...AT&CATID=YA1A2
http://www.bowtieoverdrives.com/cata...AT&CATID=YA1A2
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
Originally Posted by SuprJames
You're an LS1 guy and you're putting a big block in the car??? 
Why don't you get a SB automatic and put a LSX mated to a T56 in it?
Why don't you get a SB automatic and put a LSX mated to a T56 in it?
Yeah - why not???
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by shafrs3
Bowtie Overdrives already has a Vette crossmember made from tubing.
http://www.bowtieoverdrives.com/cata...AT&CATID=YA1A2
http://www.bowtieoverdrives.com/cata...AT&CATID=YA1A2
Very true, and they are great looking. But a skilled welder could make one for a third of that price, and customize it too.
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Burning Brakes
Joined: Dec 2004
Posts: 1,020
Likes: 1
From: Nederland Texas
Originally Posted by 68 NJConv 454
Any pics of 427Hotrods x-member???
Here is a past thread that TopGun hooked me up in my other trany x-member thread....http://forums.corvetteforum.com/show...1505590&page=2
Here's an 82 bolt in for sale...http://cgi.ebay.com/ebaymotors/Trans...spagenameZWD1V
Here is a past thread that TopGun hooked me up in my other trany x-member thread....http://forums.corvetteforum.com/show...1505590&page=2
Here's an 82 bolt in for sale...http://cgi.ebay.com/ebaymotors/Trans...spagenameZWD1V
-P
Race Director
Joined: Jan 2000
Posts: 13,018
Likes: 2,262
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
I don't have any pictures of mine handy....but it's actually very close to Bullsharks in design. I used 5 bolts on each side...but hey, I always go overkill!!
I cut mine out a little closer to the frame..but either way works.
Probably one of the best mods I ever did to the car. Sure makes it easy to do stuff!
In the future I will build a lighter one that allows pipes to go under it instead of through it. Then I can put something bigger than the 3"ones I have now. Should be easy...I'll just use the same pieces welded to frame stubs.
JIM
I cut mine out a little closer to the frame..but either way works.
Probably one of the best mods I ever did to the car. Sure makes it easy to do stuff!
In the future I will build a lighter one that allows pipes to go under it instead of through it. Then I can put something bigger than the 3"ones I have now. Should be easy...I'll just use the same pieces welded to frame stubs.
JIM
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by 427Hotrod
In the future I will build a lighter one that allows pipes to go under it instead of through it. Then I can put something bigger than the 3"ones I have now. Should be easy...I'll just use the same pieces welded to frame stubs.
JIM
JIM
If you go bigger than 3", won't you lose all backpressure? I would think 3" is too big as it is. How much air acually goes thorugh? Do you have a special circumstance?
Burning Brakes
Joined: Dec 2004
Posts: 1,020
Likes: 1
From: Nederland Texas
Originally Posted by Durango_boy
If you go bigger than 3", won't you lose all backpressure? I would think 3" is too big as it is. How much air acually goes thorugh? Do you have a special circumstance?
Check his signature to see his special circumstance.
-P
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by pef427
Durango,
Check his signature to see his special circumstance.
-P
Check his signature to see his special circumstance.
-P
Hmm. I sorta see...but 3"+ still seems big. I know I'm mistaken here, so no big deal...I just don't understand.
Race Director
Joined: Jan 2000
Posts: 13,018
Likes: 2,262
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Big myth on engines *needing* backpressure. No engine NEEDS backpressure. It's never good. Turbo motors have a lot of backpressure.....but if they can lower it and still spin turbos as needed, they will do it every time.
It is possible to lose some scavenging...which is essentially negative pressure... with too big of a pipe...but that is primarily to do with header sizing. Once you get past the collector..all bets are off. Will a 2.5" pipe kill a 500 hp motor with decent mufflers? No..it will do OK.....but a 3" won't hurt it either. You *might* make a hair more TQ at lower rpm with smaller pipes...but it would take a real small motor and it wouldn't be tuned/jetted right if it did.
I will go to 3.5" or 4" oval pipe with some creative pipe management for my next configuration. I'm getting too lazy to uncap headers these days!
Bigger IS better on exhaust pipe sizing when running a full exhaust. In fact contrary to belief, a high HP deal can be quieter with the right large case mufflers without all the racket little pipes can make sometimes.
JIM
It is possible to lose some scavenging...which is essentially negative pressure... with too big of a pipe...but that is primarily to do with header sizing. Once you get past the collector..all bets are off. Will a 2.5" pipe kill a 500 hp motor with decent mufflers? No..it will do OK.....but a 3" won't hurt it either. You *might* make a hair more TQ at lower rpm with smaller pipes...but it would take a real small motor and it wouldn't be tuned/jetted right if it did.
I will go to 3.5" or 4" oval pipe with some creative pipe management for my next configuration. I'm getting too lazy to uncap headers these days!
Bigger IS better on exhaust pipe sizing when running a full exhaust. In fact contrary to belief, a high HP deal can be quieter with the right large case mufflers without all the racket little pipes can make sometimes.
JIM
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Jim my biggest problem is finding a quiet 3 inch muffler? A 3 inch just tends to be noiser then a 2 1/2 inch.
I hate noise but do run a 3 inch exhaust under the crossmember. My 3 inch pipe is tucked right up next to the floor and straight off the header collector giving a wide birth to the trany.
I hate noise but do run a 3 inch exhaust under the crossmember. My 3 inch pipe is tucked right up next to the floor and straight off the header collector giving a wide birth to the trany.
Melting Slicks
Joined: Jan 2006
Posts: 3,028
Likes: 2
From: North NJ
Originally Posted by shafrs3
Bowtie Overdrives already has a Vette crossmember made from tubing.
http://www.bowtieoverdrives.com/cata...AT&CATID=YA1A2
http://www.bowtieoverdrives.com/cata...AT&CATID=YA1A2
Read the description..."This cross member fits all corvettes that have a removable cross member, doesn't fit 4-speed manual models)" 68-79
Nice design though, i'm sure if you had some pipe bending skills and a handy welder you could doctor one up similar.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by 68 NJConv 454
Even this would require some mods if you had a manual car.
Read the description..."This cross member fits all corvettes that have a removable cross member, doesn't fit 4-speed manual models)" 68-79
Nice design though, i'm sure if you had some pipe bending skills and a handy welder you could doctor one up similar.
Read the description..."This cross member fits all corvettes that have a removable cross member, doesn't fit 4-speed manual models)" 68-79
Nice design though, i'm sure if you had some pipe bending skills and a handy welder you could doctor one up similar.
Or do a Bubba cross member, and use a chain and two carabeeners. (Spelling?)
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Originally Posted by Durango_boy
Or do a Bubba cross member, and use a chain and two carabeeners. (Spelling?)
I'll admit that in my younger days I've chained motors down when I kept breaking motor mounts, but I'm not sure how I could chain the tranny in there.
