Quote:
Originally Posted by johnjzjz
hey pampered Z ------ you need to be very careful to check every cylinder for your piston to valve clearance
when we have a motor with issues and we need to get more we do a simple trick with a degree wheel and the valve timing - @ between 5* / 15* is the spot that the valves on over lap are at their closest -- if you use checker springs and rotate the motor you can actually measure the total distance between the valve and the piston in its cycle and adjust the cam deg if you want more bottom advance it and use the exhaust valve as your guide to how much you can with knowing .100 is the ruel -- don't know if you follow if not i can go into more detail its not for a novis to try but you sound as if you have done this sort of work and this trick is a value to those in the know about getting the most of what you have to work with -- jz
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Thank you for the offer, that is exactly how I was taught to do it. I didn't want to go into full detail with Alex until I actually have an idea of things he may not think of. I've posted on a LT1 board to have the engine builders tell me if it might be an issue. the 306 cam on a stock LT1 block, even with milled heads have plenty of clearance, but the LT4 piston and zero deck I haven't played with. I hate to have Alex put the engine together and have it go bad! A zero desk LT4 block should be a -4 flat top, so if I do the calculations right with 54cc heads and the felpro should be real ner 11,8:1 that's high for pump gas. With the drop in desk and those gaskets the intake will probably also need to be milled to match the ports back up.
This is why I'm thinking it might be cheaper to take one of his blocks and build it with something like a scat forged 355 kit would be better in the long run and be more reliable and maybe less money then the LT4.
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93Z M6 Black: The 385 Lives! Supercharged, 3-core front mount intercooler, GTP heads, 3:73's, Street twin clutch, Jethot Longtubes, Mufflex 4" catback/spintech, S+W cage, Spohn Suspenion, Yada Yada Yada
1) Build it
2) Race it
3) Break it
4) Repeat!!!
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