rebuild of 68z/28 engine questions..

[169indy]

7500 not likely, where do you plan to do that at. If planning on Racing/Street/Drag or Track then you got a LOT of work to do. But Really how often do you plan on running it in "that reality". If it is a true Car show weekend cruzer' I would think the springs warrant checking but without cycling of compressive forces and heat and cooling the negative affects of static (Relaxed) compressed would be negligible and if they were New at that time would the available stock be considered better than todays outsourced stock.

I know of locally Nine 68/69 Z owners and NONE of them are routinely spinning their 100k show car near this. They Drive differently then they Bench Race.

7,500 Yes Maybe a VERY Very Few, Please post your Videos of your Tach on your MO/DZ motors doing this on your country roads near your house.

I am not being Negative just wondering about your usage, I would think there are a bunch of Engine related things to consider If you want to routinely spin up there.

[black69]

Originally Posted by 169indy

7500 not likely, where do you plan to do that at. If planning on Racing/Street/Drag or Track then you got a LOT of work to do. But Really how often do you plan on running it in "that reality". If it is a true Car show weekend cruzer' I would think the springs warrant checking but without cycling of compressive forces and heat and cooling the negative affects of static (Relaxed) compressed would be negligible and if they were New at that time would the available stock be considered better than todays outsourced stock.

I know of locally Nine 68/69 Z owners and NONE of them are routinely spinning their 100k show car near this. They Drive differently then they Bench Race.

7,500 Yes Maybe a VERY Very Few, Please post your Videos of your Tach on your MO/DZ motors doing this on your country roads near your house.

I am not being Negative just wondering about your usage, I would think there are a bunch of Engine related things to consider If you want to routinely spin up there.

Thanks for the input. What the first owners did with this car, I do not plan to do. BUT thought once in a rare while for me, I would like to see it get to 7500 if it was designed to do that. I am lucky to put 100 miles on my cars in 5 yrs. I got the second owner telling me that his engine builder in Joliet IL had a 8K rpm warranty on it, they would replace the engine if it blew, hearing titanium straps on the mains (no idea what that means), and ultra thin compression rings to allow high RPM. I think according to my friend putting the engine together, they must have added 4 bolt main caps vs 2 which is stock? My neighbor had to have the piston compression grooves machined to allow larger 1/16 rings (which are still thin), they were that thin in the car based on the habits of owner 2, who said he copied the piston type that was in it from owner 1 (thin rings). So I am influenced by that. I never ran a small block with the rpm potential this engine has, so I plan to keep it fun and not rail road it. But would also feel safe it was built to do what it was designed to do also regardless if I ever get it up to 7500.

This car was a Nickey chevrolet ordered car that was provided at a low price to the first owner under certain conditions. He road raced raced for Nickey in another 68 z/28 and the deal was he was to bring this car to non drag events to show goodies from Nickey on the car they practically gave to him. This was a street car. What they did to the engine I really dont know, but all I have is stories on how it rev'd to the max limit often, so this is why I thought 7500 was ok for these 302s. They obviously changed the pistons from stock ring width, second owner said that was all to get max rpm.

Definitely learning redline on these is more dangerous than I thought. Appreciate the education.

[juliosz]

I had a similar situation with my 67 Z. The original owner went through the engine sometime in the late 70s and it had never been fired. I was tempted to prime the oil pump and start it but cooler heads prevailed and I had a friend go through it. Good thing I did because I found the original main and rod bearings were re-used. Another issue was the rings were stuck in the ring lands due to old assembly lube drying out. There were some other issues as well so it was money well spent going through it.

BTW, me and my buddy thought the valve springs would be shot from sitting partially compressed all those years but each of them tested good!

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