My 383 came to me with a flowsheet of the valvesprings specs. Like this:

---------------Close Pressure------Open Pressure-------Height
INTAKE1 :
EXHAUST1 :
INTAKE2 :
EXHAUST2 :
....
....
....
INTAKE8 :
EXHAUST8 :

Every valvespring has a different close/open pressure and different heigth. Thats because they measure the valve springs while they are on the heads right? Okay I see. But the lowest close pressure is 180lbs something, and the highest close pressure is 190lbs something. Engine builder told me that they will keep the pressure around 160lbs.

1)Is it not too much pressure for my hydrolic roller setup? (240/246dur. 570lift 113lsa cam)

2)If it is too much pressure, what would happen? Loss of horsepower?

 

One way you can look at this is they took the time to measure and verify everything, I would prefer to see all the same height though but you didn't say what the variance was, if slight I wouldn't be upset. I do not know how much pressure springs will lose but ask them maybe they know the spring will lose the 20-30lbs high they are set now, seems like a lot for a spring to lose but I have not tested any springs so I don't know for sure.

I think you have some valid questions, just at the same time remeber they cared enough to apparently actually measure all this which is a good sign.

 

Yes you are right they will lose some lbs, but even that I think it is too much when I think beehives' pressure is 130lbs before installing!

 

Oh and I saw my pushroads length is 7.400" ! What does this suppose to mean?? I never heard this length for a LT1, its stock length for LS1.

 

What lifters you have?

Bret

 

Morel

I really didn't understand why they used 7.400" pushroads. AFR 210cc heads come with 210lbs solid roller lifters. Maybe by using longer pushroads they install higher and reduce the close pressure? Bret?

 

No they probably were the right length. I had a 396 with Morels and longer valves need 7.300" PR's.

The Morels will handle that pressure just fine.

Bret

 

I take a picture. The highest pressure is 198lbs !! almost 200 for a hydrolic roller ??!

 

Are the Morel lifters the hydraulic lifters that are shimmed for a very small amount of hydraulic action? If so, then they act just like solid lifters and you can use solid lifter spring pressures.

I'm using Comp 977 springs for 145 lb seat pressure. I've heard Geoff mention that they've gone as high as 160 lb seat pressure on "true" hydraulic rollers, but never 190+.

Mike