What's new
By:
TurboTransAm.com

Register today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Stops pulling on the big end?

Quiky One said:
Over 20% stiffer from the 980 to 981. Just simply
not needed for 53000 rpms.

Let's agree to disagree. :)
Click to expand...

I wouldnt want to be responsible for wiping a cam.

Once those 980s are broken in I bet they near -5/-10 less than the advertised pressure at the installed height.
 
Thanks for the feedback and discussion, WOW the power logger screen shot is helpful thats crazy (anyway to lower shift point?)
So springs are needed, whats the best way to change them? how long does it take avg mechanic?
Since I'll have the rockers off should I change to roller rockers and bigger ratio get alittle more out of it?
not sure what the stock ratio is in fact?
So is the stock cam a Flat tappet or Roller? I've heard both ways?
and when eating stewed prunes is 1 enough or is 2 too many? Chevy Chase

Kyle
 
Black Shepherds & Turbo's said:
Once those 980s are broken in I bet they near -5/-10 less than the advertised pressure at the installed height.
Click to expand...

Not at 295lbs(the 981's) of open pressure...ZDDP or not he'd be flirting with wiping a lobe.
Jason's point is that if he's not spinning it to 5800-6000 why risk filling that engine and turbo with metal from a wiped lobe?

It's street car, not some big turbo'd,big roller cammed low 11 high 10 second car.

Kyle; Yours is a flat tappet cam and changing valve springs is a few hour job with the right tools.

But if your inexperienced then I'd take the heads off and have a machine shop do it right because there is installed height issues, and maybe getting the the stems cut to accept a much better valve stem seal.

And as far as shift points, I'm with Joe on the "set it and forget it" TV cable adjustment. Dicking around with the cable end is asking for trouble. If it shifts early or late after the factory adjustment then you have an internal TV valve issue or your govener needs some work.All of which I would let a tranny guy do. Automatics are like Black Magic to me and I'm amazed people can get them to hold up to the abuse we put them through.
 
Mr.Vintage said:
Since I'll have the rockers off should I change to roller rockers and bigger ratio get alittle more out of it?

Kyle
Click to expand...

Nope, not where you are now with your current set up. There's a little bit of work that needs done to make them work and of course a pushrod length change and setting up lash and all.
 
Thanks for info
I'm not pulling the heads...... you go that far time to do the motor IMO

Rotate engine over to TDC for each cylinder so as not to drop a valve in the cylinder (that would suck) get valve spring compressor and go for it!!

I would like a direct fit springs I don't want to mess with install heights and coil bind and a chance to wipe the cam

Comp 980's and what about rocker arm ratio are the stockers 1.5's could I go to 1.6's? roller?
get a little bump?
 
Stock TTA rocker arm ratio is 1.67 or 1.7 depending on who you ask. Both those numbers aro too close to worry about the .03 difference.

Maybe bigger ratio on exhaust side only:idea5:
Click to expand...

Now you're just being silly...

...
 
WOW 1.7 factory, I guess I'm used to the old small block chevy's

Probably need to do springs before Alky and pump
OK where the best place to get them?
 
went 10.90's stock everything except springs turbo an converter on a gn ..... chose what u buy 3,770lb
 
Right on, Thanks
Just to be clear I buy the 980 comp springs and I JUST SWAP SPRING FOR SPRING. and these are the replacements for stock cam?
Thanks,
Kyle
 
Thanks Guys!!!!!!!!
I install the 980 springs on the car (that was FUN.....the oil control covers were great :rofl:)
HEALED the car man, it pulls right to shift point, it pulls just like it should
ttarider
I'm so surprised that it was actually floating the valves on the top end like that nothing audible or anything? just flat....... I picked up about 800 to 1000 rpm
on the big end
Thanks Again,
Kyle
 
You must log in or register to reply here.
Back
Top