You guys are arguing about a cams ramp slope which determines the acceleration at a given speed. Listed cam specs don't tell the story that well. It would be nice to have actually graphs.

MMB, the only way I can see a spring change gaining 60hp, is if it let the valve events change significantly. That isn't necessarily a good thing for durability if it's due to lofting or something like that.

200/600

This is a 9000 rpm engine, we also measure pushrod deflection to correctly set the coil bind spec....

600 over the nose ??!!!

Imagine what the pushrods are doing at 6000 RPM's with that spring. I don't know what is in it for pushrods but they had better be really, really beefy.

I have a $100,000 personal education regarding all motor race engines. Cam Spring specs were 360 on the seat and we changed to a 270 seat. Spring Pressure eats HP, spring diameter can limit rpm etc. etc. Wrong coil bind causes spring surge and I can almost promise you if you set coil bind to the spring manufacture spec it is wrong.


You guys are getting way to technical over such a small cam change on a LOW RPM engine. He has Cam Motion cams call Kip and see what he thinks, I bet it's just fine. There is only so much they can do with a lobe down low, there not going to grind him a POS without making work the best it can. I agree it's the wrong cam and his engine is Lazy but I also feel he doest need to spend $3,000 yanking stuff out to make such a small change to the cam.

Who invented his spring spec? Bob likes heavy springs will it work with lighter springs?
If you are comfortable using heavy 1980 spring technology then by all means use it. I know what I am doing.


http://i1123.photobucket.com/albums/...6/DSC04864.jpg

His cams are from bob, and im assuming bob gave him those spring specs for that cam.

You had bob spec and design your cams in your engines didnt you?

Bob's cams come from Cam Motion. Yes Bob had my cams cut, he told me what he wanted to do and I told him what I wanted to happen. My cams have less duration and less lift then he wanted to put in it. I also used springs that were tons lighter than he wanted. and spec'ed my own PAC Racing Valve train parts.

Bob surprised me by switching to LS firing order to smooth out harmonics. It was a well engineered package from both our ideas!!


Anything Else?

Anything else? ya post an engine build thread because your boat build thread was awesome and I want more lol

are you guys going to do a dyno session with Tim? after all the time and money he put in id love to see those motors reach their potential