Comp springs WTF????

[jpwalt1987]

The Comp 26926 have an inside diameter of .654.
The PAC 1203s have an inside diameter of .624
for a difference of .030

It would be a close call.

 

[bison]

There are viton seals out there that have the
thin steel body that might fit. Otherwise just don't run seals on the exhaust.

 

[jpwalt1987]

I pulled the #3 cylinder valve springs off this morning to measure. The seals measure .575 at the widest point. The locators I have measure .660 for the spring I.d. I would defiantly need new locators to fit the ID of the spring.

It looks like with the PAC 1203s (.624 id) there would be:

.624-.575=.049/2= .0245 around the seal.

That's pretty tight. Does anyone know how much clearance is needed there?

Looking at the viton seals from Comp for a .530 guide diameter, .575 is the narrowest available

http://m.summitracing.com/parts/cca-518-16

 

[BEATAV8]

Yes unless you leave the seals off

Expect a little bit of smoke like that or maybe not so much?
Running a cast guide with a K-liner on the exhaust now. Teflon seal.

thanks!

 

[bison]

Expect a little bit of smoke like that or maybe not so much?
Running a cast guide with a K-liner on the exhaust now. Teflon seal.

thanks!

Stock used nothing and no smoke.'if your guides have more clearance you may see a puff at startup but that's it.

 

[BEATAV8]

Thanks Bison, I think I'm going to go ahead and try this set up with the 885 lifters and PAC1203 springs. Just need to get with my machinist / builder and get it all sorted out and determine if I can do it on the car or if the heads need to come off.

I'm running that 215/220 cam (.517/.530 lift) with 125# seat and 345# over the nose. Car is making a slapping/banging noise and setting off the knock sensor at WOT high RPM, and it just absolutely refuses to clean up. I got something wrong and it appears the spring pressure may be it.

 

[jpwalt1987]

Thanks Bison, I think I'm going to go ahead and try this set up with the 885 lifters and PAC1203 springs. Just need to get with my machinist / builder and get it all sorted out and determine if I can do it on the car or if the heads need to come off.

I'm running that 215/220 cam (.517/.530 lift) with 125# seat and 345# over the nose. Car is making a slapping/banging noise and setting off the knock sensor at WOT high RPM, and it just absolutely refuses to clean up. I got something wrong and it appears the spring pressure may be it.

This is pretty much the same thing I have going on. Just need to know if .0245 is enough clearance between the seal and the spring.

With a .500 guide the viton seals OD measure .546.

.624-.546=.078/2=.039

There is .0145 more room with the .500 guide vs. the .530 guide.

 

[BEATAV8]

This is pretty much the same thing I have going on. Just need to know if .0245 is enough clearance between the seal and the spring.

With a .500 guide the viton seals OD measure .546.

.624-.546=.078/2=.039

There is .0145 more room with the .500 guide vs. the .530 guide.

I would be OK with running w/o a seal on the exhaust, but will definitely look into what else is out there like the thin viton seal Bison mentioned.

 

[bison]

Thanks Bison, I think I'm going to go ahead and try this set up with the 885 lifters and PAC1203 springs. Just need to get with my machinist / builder and get it all sorted out and determine if I can do it on the car or if the heads need to come off.

I'm running that 215/220 cam (.517/.530 lift) with 125# seat and 345# over the nose. Car is making a slapping/banging noise and setting off the knock sensor at WOT high RPM, and it just absolutely refuses to clean up. I got something wrong and it appears the spring pressure may be it.

The 1203's are overkill for that. I run 26120 conical when it's less than ..550 lift. Last year I ran an old set of 941's that were about 145 on the seat with .330 lobe/1.65 rocket and it was fine up to 5900.

 

[jpwalt1987]

I would be OK with running w/o a seal on the exhaust, but will definitely look into what else is out there like the thin viton seal Bison mentioned.

Looking at the dimensions and doing some math I come up with a seal that is .0224 thick for the .530 guide. That's pretty thin. I wonder if there is something thinner. I don't want to pull the heads on mine nor do i want to use the Comp springs again.

 

[BEATAV8]

The 1203's are overkill for that. I run 26120 conical when it's less than ..550 lift. Last year I ran an old set of 941's that were about 145 on the seat with .330 lobe/1.65 rocket and it was fine up to 5900.

Looks like the 26120 would be about 30lbs heavier than what I have now. If that will do the job, awesome!

Can the extra 30lbs of load make all the difference? I have been keeping it under 6000RPM for the most part.

Also, I have 853 lifters in it now. Will they be OK to keep when using a spring like the 26120?

thanks!

 

[bison]

Looks like the 26120 would be about 30lbs heavier than what I have now. If that will do the job, awesome!

Can the extra 30lbs of load make all the difference? I have been keeping it under 6000RPM for the most part.

Also, I have 853 lifters in it now. Will they be OK to keep when using a spring like the 26120?

thanks!

I've had zero problems running more lift than you with those. I don't run 853 lifters. I doubt it would matter with those springs though. The only hyd lifter i use is 885 unless the engine had something else prior but I've never ran a fast ramp high lift with 853's

 

[BEATAV8]

After talking with Rick at Precision Engine, it looks like the PAC 1201 might be a good choice for me.

With my 1.735 installed height, the PAC 1201 would put me at 147lb on the seat. 22lb more than what I have now.
At max lift (.530) I would be at 408lb over the nose, 63lb more than what I have now.

The 1201's are rated for .550 max lift, and I would be .090 from coil bind.
Plus these springs would be a drop-in with all my current hardware.

 

[bison]

After talking with Rick at Precision Engine, it looks like the PAC 1201 might be a good choice for me.

With my 1.735 installed height, the PAC 1201 would put me at 147lb on the seat. 22lb more than what I have now.
At max lift (.530) I would be at 408lb over the nose, 63lb more than what I have now.

The 1201's are rated for .550 max lift, and I would be .090 from coil bind.
Plus these springs would be a drop-in with all my current hardware.

You could shim them at least .030 more and not have coil bind issues. The lift is theoretical on a hyd.

 

[we4Mateo]

Stock used nothing and no smoke.'if your guides have more clearance you may see a puff at startup but that's it.

Interesting. What kind of power is needed to when a seal may be necessary on the exhaust side?

 

[BEATAV8]

Interesting. What kind of power is needed to when a seal may be necessary on the exhaust side?

I don't think power would matter much. Just valve guide clearance, and to much lesser extent the style of crankcase ventillation.

 

[BEATAV8]

You could shim them at least .030 more and not have coil bind issues. The lift is theoretical on a hyd.

Thanks Daddio.

 

[jpwalt1987]

Is .0245 enough side clearance between the ID of the sprig and the OD if the seal?????

 

[fleebag]

i run the old school 914's on gn1's so far so good with 500lift but just swapped to 511.
they are shimmed but have not measured.

 

[bison]

Is .0245 enough side clearance between the ID of the sprig and the OD if the seal?????

If the springs were stable it is. Mine were very close but no problem.