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-   -   Worth it to upgrade my rockers to 10mm bolts? (https://ls1tech.com/forums/generation-iii-internal-engine/1912671-worth-upgrade-my-rockers-10mm-bolts.html)

bthomas 01-01-2019 09:21 PM

Worth it to upgrade my rockers to 10mm bolts?
 
Doing more research for my build, and didnít find anything in a search of anyone doing this. I know Tony Mamo likes to do this mod on the Yella Terraís. Anyone done this to any other style rockers?

Che70velle 01-01-2019 09:26 PM

What’s the setup? Spring rate? Rpm? What rocker you running currently?

bthomas 01-01-2019 09:38 PM

Prc 237 heads, turned down ls3 intake valves (87g), solid exhaust valves (96g), tsp pac .660 springs shimmed .060 from bind (should be approx. 175lb seat 430lb open) ti retainers, tsp roller rockers, 3/8 pushrods, Johnson 2126lsr lifters


bthomas 01-02-2019 10:09 AM


Was reading some some old posts where Martin Smallwood belived the trend to make more power with less exhaust lift was more due to valvetrain flexing than the lower lift being better.

bthomas 02-05-2019 12:05 PM

Bumping this up with some updated engine info above.

KCS 02-05-2019 01:51 PM

The larger bolt is probably better, but depending on the usage, I don't know if it would be worth it. I would think there's more deflection in the aluminum rocker body than the steel bolt.

bthomas 02-05-2019 03:29 PM


Originally Posted by KCS (Post 20042667)
The larger bolt is probably better, but depending on the usage, I don't know if it would be worth it. I would think there's more deflection in the aluminum rocker body than the steel bolt.

my rockers are steel, but point taken

KCS 02-05-2019 03:39 PM


Originally Posted by bthomas (Post 20042731)

my rockers are steel, but point taken

What rockers? Are you thinking of converting your current rockers to use a M10 bolt?

bthomas 02-05-2019 03:51 PM


Originally Posted by KCS (Post 20042737)

What rockers? Are you thinking of converting your current rockers to use a M10 bolt?

yes, and these https://www.texas-speed.com/p-7364-t...oller-tip.aspx

JakeFusion 02-05-2019 04:20 PM

Do you see deflection now in terms of valve control problems above 6500? Why do you think you need the M10 bolt?

I think you need like a PAC1207X type spring to control them. The regular platinum/400lbs open stuff won't be enough.

bthomas 02-05-2019 04:31 PM


Originally Posted by JakeFusion (Post 20042765)
Do you see deflection now in terms of valve control problems above 6500? Why do you think you need the M10 bolt?

I think you need like a PAC1207X type spring to control them. The regular platinum/400lbs open stuff won't be enough.


heads are off car currently, would be an easy upgrade. Just trying to fix any short comings I can.

A little discomforting to see you think I need more spring. I was thinking with the lighter ls3 valve that wouldnít be needed.

JakeFusion 02-05-2019 08:25 PM

You need more spring. LS3 valve helps a lot, but the MOI is still going to be what you need more control, especially as it comes closed.

In fact, I don't care that they weigh only 8 grams more over the valve. The Yella Terras are lighter than that over the valve. And they need like 170 closed and 425+ open (all they are rated to handle). It's all because the MOI is considerably higher.

Maybe you can shim up your springs and get the close pressure up to 160+ and still hopefully 400-440 open. Should be fine as long as you don't have crazy lobes.

bthomas 02-11-2019 11:11 AM

Ended up at 175 seat with the springs shimmed up

JakeFusion 02-11-2019 03:37 PM

Should work awesome.

Che70velle 02-11-2019 08:29 PM


Originally Posted by JakeFusion (Post 20046043)
Should work awesome.

Agreed.

1_fast_1le 02-13-2019 02:09 PM

I have been talking with HPR In McKinney about doing a larger bolt but, from what i have been told it will help but the base isnít as strong. i have used this LS3 head to try it would. More details to come
https://cimg0.ibsrv.net/gimg/ls1tech...4075e0e12.jpeg

HioSSilver 02-13-2019 02:38 PM

A shaft style rocker will reduce moi and help everything stay in control . By the time you mod the head for the larger bolt and buy the roller rocker you can have a set of shafts. The body is much thinner on the shaft style vs the regular roller rocker.

i just got a set of psi 1516 beehive valve springs to run on darth's old llsr cam. I like reducing mass as much as possible for added control. Hopefully it runs to 8k rpm with out issue.

1_fast_1le 02-13-2019 03:21 PM


https://cimg9.ibsrv.net/gimg/ls1tech...e5e6abb0b.jpeg

Originally Posted by HioSSilver (Post 20047269)
A shaft style rocker will reduce moi and help everything stay in control . By the time you mod the head for the larger bolt and buy the roller rocker you can have a set of shafts. The body is much thinner on the shaft style vs the regular roller rocker.

i just got a set of psi 1516 beehive valve springs to run on darth's old llsr cam. I like reducing mass as much as possible for added control. Hopefully it runs to 8k rpm with out issue.

ive been putting it off but i have been working on these lately. Itís made out of 1018 CR for sample right now. Tsp rockers were used


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