Max lift question

[blk00z28]

Does anyone know the max amount of lift we can run on a stock deck height, .030 over block with a stock crank, eagle rods, and JE pistons? The heads are bowtie with 2.00/1.60 valves and set up to over .600 lift, head gaskets will be cometic's.

This is why I ask;

I was told that if you go from a standard GM 1.5 rocker to a 1.6, it adds .050" of lift. Now I dont know if these factors or amounts change going from standard rockers to rollers.. And before I go with the cam in question I'd like to know if I'm going to have piston to valve clearance and would need to flycut them. So depending on this it will determin my cam lift and if its to much right now or not because with the figures above my cam will have almost .600 lift. If thats to much I would like to know.

Thanks

 

[dgoodhue]

Re: Max lift question

Does anyone know the max amount of lift we can run on a stock deck height, .030 over block with a stock crank, eagle rods, and JE pistons? The heads are bowtie with 2.00/1.60 valves and set up to over .600 lift, head gaskets will be cometic's.

This is why I ask;

I was told that if you go from a standard GM 1.5 rocker to a 1.6, it adds .050" of lift. Now I dont know if these factors or amounts change going from standard rockers to rollers.. And before I go with the cam in question I'd like to know if I'm going to have piston to valve clearance and would need to flycut them. So depending on this it will determin my cam lift and if its to much right now or not because with the figures above my cam will have almost .600 lift. If thats to much I would like to know.

Thanks

I can't answer the valve clearance issue. Rockers are ratio's so it 1.5:1 and 1.6:1 Our cam lifts are often given in raw lift number and with 1.5:1 ratio.

To calculate the with with 1.6 on advertised .550 with 1.5 rockers

.540/1.5 = .360 is the actual lift of the cam lobe.

With 1.6 Rockers is .360 * 1.6 = 0.576

On a smaller cam such as the stock cam .359 with 1.5 rockers

.359/1.5 = .23933
With 1.6 Rockers .23933 * 1.6 = .383

 

[Aeroking]

Re: Max lift question

http://www.wallaceracing.com/rockercalc.php

punch in 1.5 for the first box, 1.6 for the last, and your cam lift in the second box

 

[blk00z28]

Re: Max lift question

http://www.wallaceracing.com/rockercalc.php

punch in 1.5 for the first box, 1.6 for the last, and your cam lift in the second box

Thats a whole lot easier for me. lol. Some of us arnt engineers Dave..

Now that I can figure out the lift difference between rockers, the first question still is out there...

 

[Windedv6]

Re: Max lift question

Does anyone know the max amount of lift we can run on a stock deck height, .030 over block with a stock crank, eagle rods, and JE pistons? The heads are bowtie with 2.00/1.60 valves and set up to over .600 lift, head gaskets will be cometic's.

This is why I ask;

I was told that if you go from a standard GM 1.5 rocker to a 1.6, it adds .050" of lift. Now I dont know if these factors or amounts change going from standard rockers to rollers.. And before I go with the cam in question I'd like to know if I'm going to have piston to valve clearance and would need to flycut them. So depending on this it will determin my cam lift and if its to much right now or not because with the figures above my cam will have almost .600 lift. If thats to much I would like to know.

Thanks

Dependin on your pistons. Do you have the JE Extreme 23* pistons with the -22 cc inverted domes. If so you will probably be ok with .600 lift...depending on duration. A long duration keeps the valve open longer as the piston comes up. Do you have 18* or 20* heads?

John

 

[blk00z28]

Re: Max lift question

23 degree John. (you have a pm btw) and yeah I'll be running the JE's.

Thanks for the info guys. Looks like it'll work out just fine.