Comp ZS II Lobes.

[paulzig]

Watch those 1243's - they tend to loose a bit of pressure pretty quick, give em an extra 10 on the seat or watch em & shim when they sag.
Not great springs, but the installed height, pressure & rate is great in a stock valve length holden.

Spot on Tony. PSI have a new spring similar to the 1243 that should fix this problem

Comp reckon their new 26099-16 would do, and they also have people run it with their 955-16 and 943-16(looks like a PAC-1243 probably same spring) Guy wasnt sure, I went on the chat line thing as I got no email response...

Said he was going to make further enquiries and email me back.. I wont hold my breath though...

Its not a TK lobe or anything, no warnings in the blurb so I dont know... I might just do it and see.

[blykins]

If you’re not wanting to use what you have and you’re looking for options, I’ll be more than happy to give you a recommendation.

[CamKing]

Watch those 1243's - they tend to loose a bit of pressure pretty quick, give em an extra 10 on the seat or watch em & shim when they sag.
Not great springs, but the installed height, pressure & rate is great in a stock valve length holden.

Spot on Tony. PSI have a new spring similar to the 1243 that should fix this problem

What's the PSI part# ?

[turdwilly]

Watch those 1243's - they tend to loose a bit of pressure pretty quick, give em an extra 10 on the seat or watch em & shim when they sag.
Not great springs, but the installed height, pressure & rate is great in a stock valve length holden.

Spot on Tony. PSI have a new spring similar to the 1243 that should fix this problem

Are you referring to one of these?

https://www.usaperform.com/psi-valve-sp ... 1-950.html

https://www.usaperform.com/psi-valve-sp ... 2-000.html

[Neal Arnold]

26099 good spring. Used them years ago. Unfortunately got into some bad batches. Quit using them.

Psi ct1277, dr 427 rml, ct1571,1572 1580 are some that would work nice for what you have.

When we quit using the 26099 we used the second best spring that we spintron tested with. Isky 9998-rad. Use a lot of them with good results. it's a heavy piece though at 175g !

[paulzig]

26099 good spring. Used them years ago. Unfortunately got into some bad batches. Quit using them.

Psi ct1277, dr 427 rml, ct1571,1572 1580 are some that would work nice for what you have.

When we quit using the 26099 we used the second best spring that we spintron tested with. Isky 9998-rad. Use a lot of them with good results. it's a heavy piece though at 175g !

Its a 1.625 OD spring as well, but installed height is 2.05 with a 245LBS seat pressure.. I cant see the 1225 or 1243 being that much worse, I can keep RPM down and see how I go with the 1243..

[Neal Arnold]

I don't care what advertised height they have. Coil bind them all add .050 to them. Add your net lift at the valve to that . And put them on!

And people wonder why this forum has problems!

You come on here asking a question. You get some good response's to point you in the right direction.

But after all said and done you had no intention to change what you were going to do!

120 gram valve is way too heavy for one. Add a heavy steel retainer to it. And your valve train will be very noisy and unstable.

Also I have no other information to make a solid decision for your combo?
Take weight off the other pieces or buy lighter valves!

[paulzig]

But after all said and done you had no intention to change what you were going to do!

I have intention of checking both the 1225 and the 1243, and would have happily shelved them had they been completely unusable for this particular setup.

I can at this stage still change the lobe selection too, but I have since found people who have used the ZS lobe with similar valvetrain/spring setup with success. If I already own something suitable in the 1225 or 1243 after measuring for fit it is hard to justify spending more on buying a different spring like a Psi or Isky etc.

But, if that is what I have to do then I will...

[MELWAY]

Watch those 1243's - they tend to loose a bit of pressure pretty quick, give em an extra 10 on the seat or watch em & shim when they sag.
Not great springs, but the installed height, pressure & rate is great in a stock valve length holden.

Spot on Tony. PSI have a new spring similar to the 1243 that should fix this problem

What's the PSI part# ?

CT 1277

There are also more modern lobes to choose than the ZS

[paulzig]

There are also more modern lobes to choose than the ZS

Not much selection for 250@50 and under once you go over 250 by a bit it opens up.

My original plan was something in the mid 240s and lower lift, which I might have to re-visit.