what size/brand roller rock.+ v springs

[dave34]

i have 87 gn with all usual mods. car has run 11 .0,s@124 w/ very limited track duty - once a year if that . i want to race again but last time i noticed at the track i had to shift to 4th at the trap about 5500 rpm . the car runs great except that last few feet in 3rd top end . it needs a little more rpm to breath. currently im running ported irons with a 206/206 roller comp cam w/ roller lifters and stock style rocker assembly. valve springs i think are the lt1 100 to 110 lb . jack merkel in new jersey built the engine 8 yrs ago . i would like to know what everyone is running these days with my cam and horsepower level. what ratio rollers and what type spring . most importantly can i install with heads in car? do i have to modify pedestals ? whats the procedure,if so?. i,m sure i can do the install if pointed in right direction

thanks,
dave

 

[bison]

I doubt yours are 110 on the seat or the would float at about 4500. Comp 941's work well up to about 6000. Yes you can do them on the engine without pulling the heads. Ive run T&D at various ratios in various engines. I went nearly 134mph last year at 3600 lbs with only .497 valve lift. What converter you running?

 

[dave34]

running vigilanti 9.5in multidisc lockup conv. approx. 3000 stall- about 9yrs old

 

[dave34]

t.c. is vigilanti 9.5 in. lockup multidisc- about 3000 stall

 

[bison]

t.c. is vigilanti 9.5 in. lockup multidisc- about 3000 stall

What tire height measured? Bias or radial? Im thinking you should be able to get more mph out of it before going over 5500 if you are locking it. 5325 comes out to 125mph with 27" tire and no slip at 1:1. You should not be going much over 5400 in 3rd if the converter is locking unless you have a shorter tire.

 

[dave34]

28 in tall mickey thomp et streets w / 28in front runners. i know i want to at least replace stock rocker assembly with rollers . you said t and d rockers with comp 941's . what ratio - is one noiser than the other. how about beehives? any good . have you installed them w/ head on car ? how?

 

[forcefed3.8's]

Comp 941's will be cheaper than beehives.
ET streets are actually smaller than an ET Drag of the same measurement. A 28x12.5 ET Street is the same as a 28x10.5 ET Drag. A 28x11.5 ET street is barley 27" tall. Are you sure the converter is locking up?

 

[bison]

28 in tall mickey thomp et streets w / 28in front runners. i know i want to at least replace stock rocker assembly with rollers . you said t and d rockers with comp 941's . what ratio - is one noiser than the other. how about beehives? any good . have you installed them w/ head on car ? how?

I used a tool made out of a stock rocker arm and spare shaft like the one Kirban sells to install 941's on an assembled engine. Beehives are more expensive and not needed. I was running the same set of 941's for about 4 years with no problems. I did have the bigger locks and titanium retainers though. The rocker arms themselves wont make noise. If its noisey its the lifters. If you only have about .450 lift id go for the 1.65's. If your near .500 id go with 1.55's.

 

[bison]

941's on 6293 casting heads

1.700 installed height. Revved to 5900 regularly. .497 valve lift

 

[Lee Thompson]

Convertor

I would bet the convertor is not locking or if it is it is slipping. Bison --do something about that one black cyl. Take some fuel out of that one and put it in the other 2. Just kidding !!

 

[bison]

I would bet the convertor is not locking or if it is it is slipping. Bison --do something about that one black cyl. Take some fuel out of that one and put it in the other 2. Just kidding !!

That was the cylinder with the cracked piston. Its actually just oil. I unplugged the injector soon after it happened. The other 2 look just like they should on a diet of leaded race fuel:biggrin: