confused!

[good2win22]

stock spring rate is 80lbs @ 1.72
what would anyone recommend?
 and what about  open, or @ .472 ?

the springs I have are  new/ stock springs.

I would start with comp 981-12. That particular spring is advertised at 105 at 1.700 and 273 at 1.250.  I know there is at least one other fella on this board with a flat tappet that runs a spring with quite a bit more seat pressure than this spring and he does it without issue.

[Scoobum]

Watching this thread hurts. I run a 212/212 flat tappet with 130 lb valve springs with the stock rockers with solid shafts.We've swapped out prolly 2 dozen flat tappets over the years...and not one has gone flat. I was changing 981's 3 times a season...cuz they were goin' soft. I read a thread from Dusty Bradford when he raced these 109's back in the day...and he was swapping valve springs several times a season as well. Most don't run near enuf valve spring pressure...and usually buy a convertor that slips like a whore...and has the engine buzzing enuf RPM's to soften the springs in no time. Stick with a 208/208...210/210 or a 212/212 and the stock rockers with hardened or solid shafts and you won't run into issues. Start messing with valve train geometry...and all hell will break loose. I gave up trying to help people...as most prefer to struggle.

[good2win22]

Brad I was waiting for you to chime in on valve spring pressures.


Let me play the devil's advocate for just a minute. You mentioned that during a season you and Dusty were changing springs 3 times.  This brings to mind racing. Which would also imply lots of time at high rpm's albeit for short amounts of distance but still high revs. I have a sneaky suspicion that more spring pressure on a daily driver could possibly wipe a lobe on a flat tappet. 


By no means, am I an expert on this, but there is a compromise between racing and drivability.  The problem there in lies when we want both out of the same vehicle. Is it possible to run more spring pressure on a daily driver and get away with it and still have fun at the track? You bet it is possible. The next compromise is when you want to go faster at the track but still want to daily drive the buick.
It's a constant battle and you can't gain something without compromising something for it.


Good luck blown1

[blown1]

using a .060 shim, under the spring, I'm getting  98 lbs @ 1.73in
 that allows me sufficient  room for  coil bind,  and achieves  a lot better  spring  pressure.
 I'll have to see what  open pressure is, as I just did a quick check on this.

I doubt this car will ever see  a drag strip,  in the 17yrs I've owned it , it has never been there.

thanks for all the  help  you guys have offered, 

[Scoobum]

I call bullshit on wiping a cam with a heavier spring. Most don't break a cam in correctly...an d we slather the living shit out of everything with break in lube. I overboosted this engine last year...and when pulled apart...checke d the cam and lifters. Surprise surprise...nor mal wear pattern. Best thing for a flat tappet cam after break in? Take it straight to the track...and beat on it like a seal pup. At 5500 shifts...the lifters will spin like Jack the Bear. Driveability.. .nonsense. This is a tight 2800 convertor...an d with Steve Monroes TB...it drives like a stocker. On a car that never saw the track, I'd go with 981's. Oh...and piss on double roller timing chains. Stockers work best.

[Scoobum]

A quick word on the importance of good lifters...ya' pay for what you get. When I apprenticed at Custom Automotive Machine Shop we used shit ass jobber lifters. We used an old dyno with an oil feed line hooked to the engine...and spun an oil filter on it. We'd spin it up...and watch the to see how fast/slow the lifters were spinning. If one was spinning slow...then we'd grab an OEM lifter. Guess what? It'd spin so fast it was insane. My advice? Buy the best lifter money can buy.