Bundle of Snakes Advice

I hear you Jac. A good compromise would be a 1.75 bundle to the collectors if Kim is going to thrash it on the track. For the street and shows the stock 1.5 set is probably fine. I don't have any clearance issues like AJ has using the RCR stainless 1.5 set,306, and g50 trans. I'ts possible the engines are installed too high, or not tilted front to back? Dunno. I will post a pick tomorrow. If I remember right my engine is level....... S
 
Great point concerning the angle of the engine. Is the engine/trans supposed to be perfectly level in the chassis, or can it tilt a degree or two down towards the rear for better header clearance? And would that affect the shafts going to the rear tires?
 
You need to remember 'original' GT40 used small dia flywheel & bellhousing, anything larger compromises that benefit of clearance in horse shoe, also 'original' were mounted off original block mounts, each side of bell housing, two on top of transaxle, therefore 6 places, any change for porsche or other T/Axles is a compromise also, we see many porsche T/Axles mounted off rear housing, they would be better with fabricated mount in axle region that attach to top link of horse shoe along with utilising brackets from lower b/housing to horseshoe on tub. Engine should be mounted as you mention slightly tail down/nose up, not necessarily for header clearance but to ensure coolant in block and heads will tend to self bleed. When you use Audi T/Axles etc with input above axle c/l you destroy that nose high feature and may need bleed lines from rear of intake to help it out.
 
OP, I went and took pictures today at my shop. The engine IS angled up rear to front. There is at least 4” of clearance between the pipes and rear bonnet fiberglass. I will post pics when I get home and take a measurement of how far the back of the block is from the horse-shoe. S
 
Back of block is roughly 4" from front of crossmember. (top of photo is level with chassis) S
 

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Kim Haun

Supporter
Just now was able to catch up with this discussion. I verified with Fran that my engine/transaxle is placed correctly front to back. My engine does sit at an angle up back to front. I'm moving forward with a complete new fabrication of the headers. To give me the best shot at proper fitment, I'm opting for the 1 5/8" primary pipes going to 2 1/2" collectors. I'm figuring I'll lose a bit of HP at the top end but gain a bit of torque with the smaller diameter pipes. I believe Carroll Shelby said "Horse power sells cars but torque wins races." I think that quote and the lack of the smell of roasting fiberglass will help me sleep better at night.

On a positive note, the seller and I finally communicated and he has graciously compensated me towards the building of the new header set.

Thank you to all the forum members for their shared expertise and advice. I'll post the progress on my header build...

Kim
 
Sounds like the right course of action. Good luck with it. If I can ask, do you know how much a new set of headers is going to cost?
 

Bill Kearley

Supporter
Another look at the headers after installing the spider, removing # 7 pipe, close clam, line up gap spider to clam ah ah wide at the top and tight at the bottom. I can raise rear of the clam with 1/2 inch shims and lower trans mount about 3/8 inch. this will leave enough room for a heat shield. The fan idea is a good one, I think I'll need it.
 

Kim Haun

Supporter
Sounds like the right course of action. Good luck with it. If I can ask, do you know how much a new set of headers is going to cost?


Now that I'm a bit into the build I can give you a better idea on costs. With racing mufflers and interchangeable straight pipes for the track, my material costs are right at $1400. I found a great mandrel bend and exhaust parts supplier here in LA called JMD and they gave me a good 20% off what other suppliers were charging. All parts are stainless. 1 5/8" primary to 3" exhaust. It will cost around $400 to have JMD TIG purge weld everything when I'm done tacking everything together. I may have as much as 60hrs of design and fabrication time when I'm done with my end.

Kim
 
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