Blade

In an effort to try to get my broken *** transmission to shift into 2nd I took the engine to about 6500 RPM in 1st gear. One of the studs (#6intake) pulled out of the head and popped the rocker arm off the pushrod. Idle was **** and the engine felt like it was running on 7 cylinders (well it WAS). I went in there, got a big hammer and hammered the stud back in the head. Do you guys think it'll pull out again (provided I keep it under 5000 rpm) ? I'm not ready for screw in studs yet :/

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92 Z28 L98 350
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Ported and polished heads, ported stock TPI base, ported plenum, Comp Cams XR270HR-10 cam (lift .495/.502 duration 218/224 lobe separation 110), Edelbrock TES headers, LT4 valve springs, Crane AFPR, Flowmaster catback with LT1 style tips, MSD coil & wires.

Best ET 13.5@105 mph

"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)

http://www.truspeed.org/Members/Chev...dmondIndre.htm

RB83L69

Yes, it absolutely will come out again. You might get lucky and it will last until you are ready to do it right; but instinct tells me otherwise. It probably will not last 1000 miles before it pulls out again. Also, that's probably a sign that you need better valve springs; I have never seen any 1.25" springs sold by any vendor other than GMPP that were spec'd for anything in excess of .500" lift; and even then, they aren't recommended for more than .480" or so by anybody else. I'd bet that within a few more warranty claims even GM will have to rethink spec'ing that part for that application, just like Comp and Crane and all the other companies that have been making such things for all these decades. (GM's racing operations have always used aftermarket springs... GM therefore basically has no experience in that area)

Oh well, I know it's not what you wanted to hear, but...


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"So many Mustangs, so little time..."

Blade

Damn... Those LT4 springs are supposed to hold up to that kinda abuse though, shouldnt they ? This is the first time I ever revved my engine that high... I didnt even think it couldnt handle 6500 RPM at least ONCE w/out breaking something. hehe

vortecfcar

6500 with heat on = vacaion for heater core

I thought for sure I fucekd somethin up when I planted the gas with the trans in first and 225 series tires :O.

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 280 grind. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, ****ty stock converter
13.24@104

ede

you can try to pin it in if you don't want to swap heads or put in screw in studs.

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-=ICON MOTORSPORTS=-
1st & 3rd

Blade

What do u mean "pin it in" ?

Ward

iTrader: (1)

I have had bad experience with high rpm...(and ford). Me and my bud were working on his 65 mustang, and we changed a heater hose when we changed the intake and carb. Well, dumb us, once we got it running good we decided to take it for a spin and see what it could do now with the new 4 bbl instead of the old 2 bbl carb. He took it to baotu 6200 rpm to pull off a badass scratch (auto trans with B&M shift kit) ad wouldnt ya know, the heater hose popped off the fitting and soaked the engine compartment (and the road hehe) with antifreeze. turns out the clamp has to be on REALLY tight.

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1983 Pontiac Firebird SE
LG4-Based Chevy 400
700R4 Tansmission
Modified 4 Barrel Q-Jet Carb
Accel Super Stock 8mm Wires
Edelbrock Pro-Flo Air Cleaner
3.23 Posi Rear
14X7" Cragar SS/T Wheels
35X4 CD/AM/FM Head Unit
100WX2 Amp
2 Pioneer 12" Subs in Custom Box
Third Gen Performance

[This message has been edited by Ward (edited November 30, 2000).]

RB83L69

Drill through the boss and stud, and put a roll pin in it

Some people use racial epithets to describe that sort of thing

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"So many Mustangs, so little time..."

Guest

There is also a .003 oversize stud that you can get and use to fix that problem.

Blade

Well it hasnt come out yet. Nor does it show any signs that it will. So I will leave it alone until it happens again (let's hope not)

Guest

I wouldnt advise doing that. They always pull back out after its happened once. Take it from someone who worked in a machine shop for 7 years.

ede

rb i didn't say i'd pin it, i was giving him some differant things to try. yes a roll pin is a poor way to fix it and i doubt if you'd call it a long term fix.

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-=ICON MOTORSPORTS=-
1st & 3rd

JakeJr

High RPMs and/or high spring pressures with a performance cam = pulled press-in studs.

If it happened once, it'll happen again and next time you might not be so lucky. If a stud pulls again, it could cause the rocker to side load the retainer and you could drop a valve. Now that's a big time problem!

Unfortunately the fix is easy, but is a lot of work. It involves pulling the heads.

Best way is to have the stud bosses milled down and the holes tapped for screw in studs and guide plates.

Don't feel like the Lone Ranger, I had the bite that bullet last year when I kept bending pushrods while playing with my new ZZ9 and 1.6 roller rockers.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

zroc

with the cam you have you should be using screw in studs... I was adlust the valves on my 68 camaro one day and all the sudden one started seeping coolant... off came the heads and screw in studs were installed... every high perf engine should have the insurance of screw in studs...

zroc

Ward

iTrader: (1)

What all does it take to install screw in studs? Can I do it at home? I got alot of tools, lol

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1983 Pontiac Firebird SE
LG4-Based Chevy 400
700R4 Tansmission
Modified 4 Barrel Q-Jet Carb
Accel Super Stock 8mm Wires
Edelbrock Pro-Flo Air Cleaner
3.23 Posi Rear
14X7" Cragar SS/T Wheels
35X4 CD/AM/FM Head Unit
100WX2 Amp
2 Pioneer 12" Subs in Custom Box
Third Gen Performance

ede

i install my own screw in studs at home. it really depends on what you have at home to work with. you have to mill .4 off the stud boss for arp screw in studs,tap the holes 7/16-14, take a 7/16 drill bit or reamer and remove about a 1/4" of thread at the top of the hole and use a counter sink to chamfer the top of the hole. it's pretty involved process, but i'm a cheap bastard and i can save a few bucks doing it myself. oh yeah one other thing,if you see the DIY stud boss cutters don't buy one they don't work and aren't accurate. use a end mill to reduce the boss height.

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-=ICON MOTORSPORTS=-
1st & 3rd

rsc350

.4 mills or inches??? Ede help me out here

ede

.4 inches

tommyboy

Use a Stud Boss cutter, then hit the extra material off with a chisel. Chisel the boss smooth, then use a Proform stud tapper tool. Not that difficult. Cost in tools, $100.00. If you need a picture of how to do this, I will gladly help a fellow brother out.

rsc350

where do i get a stud boss cutter?

ede

i got a manley from bill mitchell for around 100 dollars, it's worth about 2 cents and doesn't work. i woudn't waste my time or money on one.

Chris B

Just an FYI....my COMP CAMS 918s are spec'd for over .600 and they are 1.25 in diameter.

Aron213

I always go .350 for studs and .400 for studs and guide plates

RB83L69

Not to be a twerp; but I've done some engineering work for Comp Cams over the years when they've needed it. I could be wroong but I think I know their product line, at least the part that thye've had for 20 or 30 years or so, fairly well.

918s are spec'd to .500" of lift. Look through their catalog. You'll find that if valve lift exceeds .500", they recommend some other spring.

As far as how to mill them, the correct answer is how much you leave, not how much you take off. But on an average typical stock head, if you set up your mill to take off an average from each boss of about what either Aron or ede says, making sure that all the bosses are the same height, you'll be about right. The exact dimension isn't very critical since the Chevy valve train is adjustable. Just avoid taking off so much that the bottom of the studs hits the intake ports.

Chris B

RB....

I guess should not have shortened the part number. I've worked around too many LS1's I guess. The part number I was refering to is the 26918 which specs at .625 lift and has a diameter of 1.29... I use them with a conversion retainer...778. I may not have done engineering work, but I sure have done enough valve spring changes and R&D on what works and doesn't... In case you don't have the updated catalog, It looks like they have a supplmental in JPG on the web COMP CAMS CATALOG

THREAD CONTENT

These springs WILL pull your pressed-in studs out

CB