1-3/4 ~ 2 turns of lifter preload???
08-05-2003, 11:12 PM
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1-3/4 ~ 2 turns of lifter preload??? I have milled heads and after market cam (230/230 .578/.578) and I preloaded the lifters 1-3/4 to 2 turns as almost everyone agreed then.
But a quick search now showed me that some peoples agree on 1/2 of a turn is OK...
My question is:
Do I have too much lifter preload as of now???
Granted my valvetrain is very quiet... but do I risk lifter collapsing at high rpms???
Need help quickly on this one.
But a quick search now showed me that some peoples agree on 1/2 of a turn is OK...
My question is:
Do I have too much lifter preload as of now???
Granted my valvetrain is very quiet... but do I risk lifter collapsing at high rpms???
Need help quickly on this one.
08-06-2003, 08:49 AM
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Re: 1-3/4 ~ 2 turns of lifter preload??? what type of rockers and what application does this reguard to? i can only assume that these are not the stock pedastal mount rockers, and some kind of lock nut SBC/LT1/SBF ect.. type of rocker. is a solid roller? is it a hydraulic flat tappet? is it a hydraulic roller w/ something wierd no-one's ever heard of? a little bit more info would be great.
08-06-2003, 11:01 AM
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Re: 1-3/4 ~ 2 turns of lifter preload??? I wouldn't go more than a half turn ever. Your liable to get burned. If you go too little preload the only thing you risk is a noisy valve train. If you go to tight you could be risking holding a valve off it's seat and burning it. Ouch!!!!!
08-06-2003, 12:09 PM
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Re: 1-3/4 ~ 2 turns of lifter preload??? I use stock pedestal rocker with Stage II Heads.
So I risk burning my valves???
What if I already have 600 miles since then?? Are they already damaged?
So I risk burning my valves???
What if I already have 600 miles since then?? Are they already damaged?
08-06-2003, 12:43 PM
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Re: 1-3/4 ~ 2 turns of lifter preload??? Ok, but would it be better to re-shim them a little bit more just to make sure I am in the 1/2-3/4 turn ballpark?
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08-06-2003, 02:34 PM
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Re: 1-3/4 ~ 2 turns of lifter preload??? i'd think so. i have a tendancy to be **** about little things like that, because it's better safe than sorry when it comes to stuff like this. i personally like to do 1/2 turns on adjustable valvetrain, but you do have to check it every so often to be sure the pre-load is right. ;D
08-06-2003, 03:12 PM
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Re: 1-3/4 ~ 2 turns of lifter preload??? Chris, i thought i read that were the jessel style w/ adjustability but re-reading this, im not so sure..
if you have adjustable rockers, use this adjustment procedure, but if they're stockers and you're trying to adjust them, it's not the best idea. you'll end up throwing rockers/ p-rods or worse, damaging the head or entire motor. just torque them all to 22 ft-lbs
if you have adjustable rockers, use this adjustment procedure, but if they're stockers and you're trying to adjust them, it's not the best idea. you'll end up throwing rockers/ p-rods or worse, damaging the head or entire motor. just torque them all to 22 ft-lbs
08-06-2003, 04:11 PM
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Re: 1-3/4 ~ 2 turns of lifter preload??? No.. I'm not talking about Adjusting the rockers themselve but about using shims to change the preload just as I did to get my current 1-3/4 to 2 turns
08-06-2003, 04:20 PM
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Re: 1-3/4 ~ 2 turns of lifter preload??? how much are the heads milled and what cam are you using?
the rockers stay non-adjustable reguardless of a shim. it would work, but you really need shorter pushrods if you're using a small BS cam and have milled more than .030 off the heads.
the rockers stay non-adjustable reguardless of a shim. it would work, but you really need shorter pushrods if you're using a small BS cam and have milled more than .030 off the heads.
08-07-2003, 01:09 AM
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Re: 1-3/4 ~ 2 turns of lifter preload??? I do have 7.350 pushrods, MMS 230/230 .578/.578 112lsa, and .030 milled heads
I currently have one .030 shim under the rockers pedestal and I could easily insert another 0.30 shim as well... piece of cake... I was just knowing that there should be that much preload at the time but since I need less preload I will use those spare shims I still have.
I currently have one .030 shim under the rockers pedestal and I could easily insert another 0.30 shim as well... piece of cake... I was just knowing that there should be that much preload at the time but since I need less preload I will use those spare shims I still have.
08-07-2003, 04:08 PM
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Re: 1-3/4 ~ 2 turns of lifter preload??? if you've milled the heads .030, and have a MMS cam, take the spacers out get some 7.4 (stock length)pushrods, and tighten all the rockers down to 22ft lbs. ~viola you're done.
i know, thats how mine runs. -.30 off the heads, stock p-rods, Comp cam. no spacers. this brings the valvetrain geometry prety close to stock
now, you need to either that or take some more material off the heads, (which i wouldnt do w/ that cam) or get stock p-rods in there and ditch the spacer. with spacers, and 7.35" p-rods you're -.60 out of preload from stock. you had the right idea, just went in the wrong direction.
hope that helps.
i know, thats how mine runs. -.30 off the heads, stock p-rods, Comp cam. no spacers. this brings the valvetrain geometry prety close to stock
now, you need to either that or take some more material off the heads, (which i wouldnt do w/ that cam) or get stock p-rods in there and ditch the spacer. with spacers, and 7.35" p-rods you're -.60 out of preload from stock. you had the right idea, just went in the wrong direction.
hope that helps.
08-08-2003, 08:35 AM
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Re: 1-3/4 ~ 2 turns of lifter preload??? OOps... I was wrong on the 7.350 pushrods... I got comp cam hi-tech 7.4" pushrods...
Still when I installed the rockers back then I noticed that the preload with no space was in the 2.5 turns range...
That is why I need to use spacers!
My cam has a much smaller base circle than the stock cam and even with the milled heads I still more than 7.4" ...
Still when I installed the rockers back then I noticed that the preload with no space was in the 2.5 turns range...
That is why I need to use spacers!
My cam has a much smaller base circle than the stock cam and even with the milled heads I still more than 7.4" ...
08-08-2003, 09:52 AM
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Re: 1-3/4 ~ 2 turns of lifter preload??? um, i still dont understand where you get this notion about turning the rockers a specific # range. the rockers are non-adjustable and the lifter is the only ting here that adjusts for pre-load. take the spacers out, use 7.4 pushrods and tighnen all the rockers down to 22ft lbs. the lifters compensate +/- .80 anyway so your fine. believe me, i know, this is how i've run a few of my motors, and it works. ditch those spacers.
08-09-2003, 10:30 PM
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Re: 1-3/4 ~ 2 turns of lifter preload??? I did shim my rockers 0.030 and now my pre-load is around 0.75 turns, which seems much better than the 1.25-1.5 turns they previously had.
When I start the engine COLD if will make a little bit more valvetrain noise than it was making before but once the MOTOR has reached temperature there is no more valvetrain noise as usual (not like stock though...)
When I start the engine COLD if will make a little bit more valvetrain noise than it was making before but once the MOTOR has reached temperature there is no more valvetrain noise as usual (not like stock though...)