Cam question for the group

[Mr.Spool]

Yeah at peer tech my car was 3780#. I’m not going to find 340 # worth of stuff to cut off of the car but I agree, rotating weight is a hp killer. From the build sheet, the original builder did a great job with quality parts and tolerances on the build. I think what I have in mind for it will put me into the low 9s high 8s. About 5 or 6 changes coming during the refresh should do it. Almost doubling the injectors as well for the e85.

That's alot of weight to have a high 8/low 9 sec goal.
I've been there and done that.
Losing 400lbs is not as hard as you would think and takes alot of pressure and will increase the longevity of the car.

 

[BEATAV8]

Yeesh.... mine has 150 seat and I'm going up to 195-200 seat.
With 150 seat she gets pretty lazy around 6000 @ 130mph. 215/220 FTS cam with 1.60 rockers. Unported champions.

I've seen beehives go to 6250 @ 137mph with 130 seat but the parts did not look good on teardown. Valve float was bad.

 

[jckcolarusso]

My friend it’s goin to be a crapshoot trying to get a timing chain to live with 195 - 200 closed Pressure

 

[Haulz A]

My friend it’s goin to be a crapshoot trying to get a timing chain to live with 195 - 200 closed Pressure

Running 195-220 lbs springs seat pressure is a common thing with THS/TAI/TPB/TSM/TSO cars with Alluminum or steel heads. Alluminum heads just require steel or titanium spring locators to prevent cylinder spring pocket wear. Just need to use a high quality timing chain such as roll master double roller which TA performance sells- Also ensure the cam bearing are installed properly, set the end play of the camshaft .005-.008 by shimming the comcamp camshaft roller button, modify your lifter oil galley plug to spray oil on the timing chain gear set, ensure the cam/crank line bore is within specs/aligned proper, ensure the rotating assembly is properly internally balanced.

Thats the recipe for a suscessful high boosted engine which will prevent timing chain failures as long as your machine shop can provide quality work and your engine builder can verify the machine shop work prior to assembling your engine.

 

[BEATAV8]

I use the IWIS / roll master timing sets. This particular engine has a pre-stretched IWIS chain installed on it too. They're pretty tough. I saw one eat a stock chain tensioner once (wasn't my build! lol). That tensioner went through the timing set between the chain and the sprockets and stretched the chain all to hell but it didn't break it. Plenty of my partners in crime are around 200 seat already. I'm behind the times!

 

[Haulz A]

Cool beans- I don’t run a tensioner with my double roller timing chains- I just play with different size sprockets and timing chains until I get the right tension on both side of the timing chain- you have to buy extra part In- order to get that tension right

 

[Buick Mark]

rpm’s

RPM

 

[Buick Mark]

You could also drop gearing to a 3.23 to get more rpm.

From 3.42 to 3.23 will reduce rpm

 

[jckcolarusso]

From 3.42 to 3.23 will reduce rpm

Yes

 

[jckcolarusso]

most guys run 3.23 with a t 400 trans

 

[Mr.Spool]

From 3.42 to 3.23 will reduce rpm

Yes sir

 

[Pronto]

I know someone that tried them with a 200r4 and they didn't help their times.

 

[Mr.Spool]

I know someone that tried them with a 200r4 and they didn't help their times.

I think your going to see a hit or miss with the gear change across the board
That's combo specific.
Some guys have gone faster some slower.
I've seen it both ways

 

[BEATAV8]

Just recently finished up my spring change. 205 seat and 435 open. Sounds nice. Will see how she responds.

 

[TIMINATOR]

Just recently finished up my spring change. 205 seat and 435 open. Sounds nice. Will see how she responds.

How much preload on the lifters? Is it adjustable?
TIMINATOR

 

[BEATAV8]

How much preload on the lifters? Is it adjustable?
TIMINATOR

.040" (3/4 turn)
Johnson lifters

 

[TIMINATOR]

Reduced travel, or normal?
Slow leakdown, or normal?
Normal lifters have about .190" travel, did you check yours?
When lifters bleed down, it makes the effective cam duration shorter, and lift less. You may find that you didnt gain much, or anything from the springs, because the cam now "thinks" it is smaller. Reread my previous lifter posts.
As lifters wear, they bleed down faster too. Plunger to lifter bore is in the low ten-thousandths or less. It is said that the most effective oil filter in the engine is the hydraulic lifter. It starts wearing larger at its first use.
Run the new springs for a while, keep good records on every pass: engine temp, oil temp, E.T., and MPH.
Once you have a good baseline, try deeper preload, and compare the results.
On our HP, large cammed Harley engines, we have seen 5+ HP gain on a 2 cylinder, 136 HP engine! H.D.s use Chevy hydraulic roller lifters, with a limited upper end oiling rate.
Just something to try, to make more, reliable, H.P.
I lash mine a half turn up from the BOTTOM. Everything "grows" up from the lifter, so you have plenty of travel where you need it when hot.
In the old days on the STOCK ELIMINATOR class drag cars, we kept a half dozen sets of brand new lifters, filled with 140 wt. gear oil and replaced them every pass in eliminations. They checked to make sure we ran hydraulics, after they caught us running solid lifters on hydraulic cams. They never figured out the 140 weight deal, as we ran the motors at a high RPM on the return road, to wash it out before we went to tech....
Higher RPM, and high exhaust turbo back pressure, collapse the lifters, making the cam seem smaller. Try it and see, its "free" HP!
Have you ever noticed why some turbo cams run longer exhaust duration?
TIMINATOR

 

[BEATAV8]

Reduced travel, or normal?
Slow leakdown, or normal?
Normal lifters have about .190" travel, did you check yours?

TIMINATOR

Reduced travel. The leakdown spec I do not know off hand. I was not aware Johnson even offered options for leakdown rate.
Oil is 0W-40

 

[TIMINATOR]

Reduced travel. The leakdown spec I do not know off hand. I was not aware Johnson even offered options for leakdown rate.
Oil is 0W-40

In sbc apps, they have over a dozen travels, rates, and upper oiling amount combos. As long as you followrd the exact installation instructions, you should be golden. Call their tech line and ask what the travel is for your part#. There may not be much more HP available, but ask. The normal hydraulic lifter plunger travel for all of the hundereds of normal travel lifters that I have checked is from .182 to .203" depending on brand and lot.
H.P. is where you look for it.
TIMINATOR

 

[Haulz A]

In sbc apps, they have over a dozen travels, rates, and upper oiling amount combos. As long as you followrd the exact installation instructions, you should be golden. Call their tech line and ask what the travel is for your part#. There may not be much more HP available, but ask. The normal hydraulic lifter plunger travel for all of the hundereds of normal travel lifters that I have checked is from .182 to .203" depending on brand and lot.
H.P. is where you look for it.
TIMINATOR

Attached is a PDF file which my explain a little more into detail concerning Buick valve adjustment. Timinator you have posted some interesting info about valvetrain adjustment which is very useful info. Hopefully BEATAV8 will get his valvetrain optimize to utilize every bit of that camshaft profile in the areas he wants the engine to perform.

Haulz A