PAC 1521 Springs?
FormerVendor
Joined: Dec 2001
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From: WWW.SPEEDINC.COM
both 1521 and 1221 are dual springs
the 1221 springs have been the PAC LS1 .650" dual spring for quite a few years, you can use Comp Cams 754-16 or REV makes a retainer that will fit them. Comp's new lightweight tool steel LS retainers could perhaps fit.
If the 1521 carries over same spring dimensions the comp cams 754-16 retainers are fine.
the 1221 springs have been the PAC LS1 .650" dual spring for quite a few years, you can use Comp Cams 754-16 or REV makes a retainer that will fit them. Comp's new lightweight tool steel LS retainers could perhaps fit.
If the 1521 carries over same spring dimensions the comp cams 754-16 retainers are fine.
I run the PAC 1521's with Comp 921 retainers. They are dual springs. Nitrited for longer life. I think these are probably the best drop-in's available plus they are good for .700 lift. Trending Topics
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So the Comp 921 retainers work but the Patriot's need some machining. What about the spring bases for either the Comp's or the Patriots.
Thanks for all the help guys-I'm wondering why more people don't use these?
Thanks for all the help guys-I'm wondering why more people don't use these?
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From: Waterloo, Ontario
Here are the specs from PAC:
160 lbs@ 1.800
435 lbs @ 1.150
408 lbs/in Spring Rate
1.080 Coil Bind
1.300 OD or Outer
0.895 ID of Outer
0.655 ID of Inner
Max lift - 0.700 inches with a tall install or tight coil bind clearance
These are perfect spring for FI build, I'll be switching over a couple of cars to these.
However there not cheap-about triple the price of the Patriot Extremes.
I know of only one guy that my have them.
160 lbs@ 1.800
435 lbs @ 1.150
408 lbs/in Spring Rate
1.080 Coil Bind
1.300 OD or Outer
0.895 ID of Outer
0.655 ID of Inner
Max lift - 0.700 inches with a tall install or tight coil bind clearance
These are perfect spring for FI build, I'll be switching over a couple of cars to these.
However there not cheap-about triple the price of the Patriot Extremes.
I know of only one guy that my have them.
Scoggin Dickey didn't send me locks when they sent me retainers with the PAC1521 springs.
We put the Patriot retainers and locks onto the PAC springs. It seems to work???
Like they fit really well?
So, the dumb question: Did you try it?
Last edited by Grendel; Jan 24, 2011 at 05:58 PM. Reason: Correction on retainers.
We did not send comp cams anything except the pushrod checker. We send the AFR retainer as it does fit and is less $$$ than alot of the others.
This is the first I have heard of the patriot parts fitting the PAC springs, but the main part is, do they fit to within Pacs recommendations? Or at that point, well enough to not move at all when both springs are engaged on the retainer. And the seat as well. The seat is not just there as a shim. It is supposed to locate the ID of the inner spring also.
This is the first I have heard of the patriot parts fitting the PAC springs, but the main part is, do they fit to within Pacs recommendations? Or at that point, well enough to not move at all when both springs are engaged on the retainer. And the seat as well. The seat is not just there as a shim. It is supposed to locate the ID of the inner spring also.
We did not send comp cams anything except the pushrod checker. We send the AFR retainer as it does fit and is less $$$ than alot of the others.
This is the first I have heard of the patriot parts fitting the PAC springs, but the main part is, do they fit to within Pacs recommendations? Or at that point, well enough to not move at all when both springs are engaged on the retainer. And the seat as well. The seat is not just there as a shim. It is supposed to locate the ID of the inner spring also.
This is the first I have heard of the patriot parts fitting the PAC springs, but the main part is, do they fit to within Pacs recommendations? Or at that point, well enough to not move at all when both springs are engaged on the retainer. And the seat as well. The seat is not just there as a shim. It is supposed to locate the ID of the inner spring also.
Correct, I didn't receive the seats or locks and ended up using Patriot seats, retainers and locks. I'll post a video, as the motor's together. There is no coil bind or spring movement. From the post above, you need to trim the Patriot retainers down to fit the PAC1521 springs... I had to do no such thing and they fit tightly. Not interference tight, but less than 1MM difference with calipers.
Also, it seems that it took stock push rods just fine.
I am second guessing myself here and can't get empirical evidence without disassembling my motor... and I don't want to void the machine shop warranty, considering they did all this assembly.