Saving a non zr1 guy's azz.

[rhipsher]

This guy comes in the shop and hands me a double roller timing chain gear and hands me a little sketch of what he needs done. He just needs a few diameters turned down. It's to a 428 FE big block thats going into a Cobra kit car. He says he'll bring it by when he's done building it. I jokingly said I'll race you. He says oh yeah? What do you have. I told him. He askes how fast will it get to 200mph? I said I can't get to 200 but I can get to 180+ pretty quick. As light as that Cobra is I know I'd get my butt kicked. So shoot ahead to today. The same guy calls me up and says he just stripped out one of the rocker arm studs. He said when he was tightening the rocker arm down the helicoil started pulling out. He was freaking out and yells "What do I do"?. I wanted to say well man your f*cked. Hehehe! But I just couldn't bare to do it. So I told him we can tig weld the hole back up with aluminum drill it retap and helicoil it. Problem solved. I think he screwed up and set his torque wrench to high or something. So he is bringing it by tommarrow. Those cobra kit cars are freaken awsome. Id love to have one some day.

[phrogs]

Why was there a helicoil in it to begin with? when I was a machinist I only used them to repair a thread not to be the actuall thread.

I saw this on my old aircraft the V22 there was a spot that had helicoils in it that worked there way out and cost alot of headaches.

but if it already had a helicoil why not just remove the damaged one and replace the helicoil? he must have really done a job on that head to damage the helicoils threads as well

[rhipsher]

He said it looked like a previous repair. Sometimes they don't always tell you the truth. Once we get it will be easier to see what happened. I asked him how deep the stud screws into the head? He said 1/2. 1/2 doesn't seem deep enough to me. But then again I've never seen a 428 head in the flesh so I don't know.

[jonszr1]

if its an edelbrock head they heilicoil the rocker studs . be carefull there was a 428 cobra kit car at fontana dec 5 it ran 10.30 @135 mph it on u tube under fontana drags its the 9 min video . sure was a pretty car, even had a very small windshield so the poor guy ate a ton of bugs

[flyin ryan]

Heli-Coils on Alum. heads are common. I'm gonna stay off the Cobra car band wagon . Nice of you to help this guy out...sounds like he needs it, maybe he'll put you on his payroll. Myself, I'd never put a big heavy F.E. lump in the engine bay. 550HP 347 cube would be decent power & handle a ton better. Just my opinion, but then again I'm not a fan, LOL....

[rhipsher]

Oh trust me Ryan he's not getting any favors. He is being charged $100 an hour for it. And thats for manual machine time. If he saw what the CNC shop rate was he would have a heart attack. Luckily for him this won't require that.

[bb62]

Originally Posted by rhipsher

He says oh yeah? What do you have. I told him. He askes how fast will it get to 200mph? I said I can't get to 200 but I can get to 180+ pretty quick. As light as that Cobra is I know I'd get my butt kicked.

I don't care what he has in that Cobra, he will not achieve 200 MPH and he will not have a higher top end than your ZR-1. Those cars have the aerodynamics of a brick. Shelby even had to have Pete Brock design the Daytona Coupe to get the top end he was looking at to compete with Ferrari back in the mid 60s.

[rhipsher]

Originally Posted by bb62

I don't care what he has in that Cobra, he will not achieve 200 MPH and he will not have a higher top end than your ZR-1. Those cars have the aerodynamics of a brick. Shelby even had to have Pete Brock design the Daytona Coupe to get the top end he was looking at to compete with Ferrari back in the mid 60s.

You may be right. I've taken mine up to 150mph with the top off and that was painful. The drivers side seatbelt was slapping all over the place and the wind just beats the crap out of you. 179mph with the top on wasn't near as violent. And Cobras have no top. Yes I know they make one but it looks goofy as hell.

[flyin ryan]

Originally Posted by bb62

I don't care what he has in that Cobra, he will not achieve 200 MPH and he will not have a higher top end than your ZR-1. Those cars have the aerodynamics of a brick. Shelby even had to have Pete Brock design the Daytona Coupe to get the top end he was looking at to compete with Ferrari back in the mid 60s.

I agree with that!