TA 413 Cam

Like JW said, as long as everything is perfect in the valvetrain you can run the higher ratio rockers. it's when things are out of whack that he has seen problems. This build probably has everything setup just right for his cam/rockers.

 

Friday is Dyno Day. I will be running full length headers and my shorties with my head pipes. Swapping on an SP1 during the day. Swapping the stamped steel rockers for the rollers. We'll see what we come up with.

 

Were the heads valve stem heights correct?

 

Based on the notes the shop made when he did the valves they were all spot on.

We're really not sure what we'll find. Is the intake a restriction? Are the shorties a problem? Is there some weird reversion happening at max valve lift?

Hopefully we'll have answers for everyone on Friday night.

 

I hope you get some answers. In the big car, I'm running a TA413 with 1.60 rollers and it will sail right on past 5600RPM. Has TA stg1 SE heads, Q-jet, HEI, Performer intake and long tube headers.

 

Just read this whole thing. JW, if I am understanding correctly, the lifter "crash" you experienced was where they aren't pumping up but rather the opposite having their oil squeezed out of them causing excessive lash. I am wondering if you tried other brands of lifters (still hydraulic) while experiencing this? Is this also irrespective of oil pressure?

 

Seems like if someone ran this cam back to back with a set of solid lifters and no other changes, I should answer the question of lifter crash. Mike at TA once told me a customer did this and picked up 10 hp. Would be interesting...

 

in my motor referenced by JW that he built, oil pressure certainly is not an issue. 10w30 hot, 750 rpm idle is 25-30 psi, breath on the throttle and it jumps instantly. 2700 cruise rpm and im just below 60psi.

 

I have seen this with the old Johnson Hydraulic, Melling, Delphi, and Comp Cams lifters. I have seen this in motors build all thru the last decade, with all the various lifters that have been available in that time. Almost every time, reducing the load on the lifters is the only thing that has had any effect on the problem.

Tried increasing oil pressure before.. no difference. Taking the lifters apart, and re-drilling the holes to allow more volume to them, might be a reasonable course to follow, but I have never tried it.

JW

 

That's a good idea Rob, I will put a set of solids in my dyno shop bucket for the upcoming tests.

JW

 

Thank you, in a perfect world, I'd like to see the swap done back to back on an engine that shows the problem....like Yardley's. Although I don't think it will be too tough to find another candidate. Do you have a set of solids to try?

 

No, I would have to buy a set... got a good used set laying around?

JW

 

I think I might have a new set and I'm also working on a project with a buddy, his engine has a solid in it now, depending on what his next move there is, we may have a good used set. If not and if I do have a new set, I'll gladly donate them to help find the answer.

 

Thanks Rob..

JW

 

Besides swapping roller rockers to stock ones, has anyone tried roller rockers and 5/16 pushrods? If weight and the rocker ratio are factors, the push rod weight may have an affect also. Just a thought. Maybe it's been done before or if 5/16 were run, were the flexing? Interesting situation...

 

From what I've read, 5/16" seems to be what JimW runs on a regular basis, even on some of his higher output engines.

Devon

 

Ya, no problem with TA's .080 wall 5/16 pushrods..

It's what we ran on Sweesy's monster roller cam, with just shy of 800 lbs open pressure..

I don't bat an eye on using them on anything with normal solid/hyd cam spring pressures.

Not much use for 3/8 pushrods around here..

JW

 

OK. We have an answer!!!!!!!!!!!!!!!!!!!!!

We bolted it on the dyno with the stamped steel rockers and B4B, and with jetting changes it would peak at 4700 RPM and then just literally drop like a stone after that. Not a gradual fading of power. And the power curve wasn't a curve at all, but rather a zig-zag like the design on the front of Charlie Brown's shirt. It was all over the place.

We swapped to the roller rockers and the peak moved to 5000 RPM. But it was still a zig-zag pattern and then would drop like falling off a cliff. Max power was 440 HP. When we broke in this engine the max was 441HP. So we were right there.

No matter what we tried, nothing helped. Timing changes (it likes 30* the best), jetting, 1" spacer. Nothing really made much of a difference.

Then we swapped on a borrowed SP1. And with jetting we hit 470HP @ 5400 RPM!!!

The curve smoothed right out then faded nicely after 4400 RPM, just like it should. No more zigzagging.

So it is obvious that my heads don't like the B4B. We've never seen max torque on any dyno pulls we've done on this dyno because it is a water brake and to get the engine to pull correctly they have to engage the load at about 3000 and then they record at about 4400RPM. Max torque is well before that and the numbers are already coming down when they begin recording. The best torque we got today was 525 lb ft @ 4400 RPM.

I do have 1 lifter that bleeds down quickly after sitting a few minutes (could possibly by my knock-on-startup) and another that bleeds down less rapidly. I'll be replacing those lifters when I bolt on my new SP1.

But 30 HP with an intake change!

 

<a href="http://s253.photobucket.com/albums/hh41/1badriv/455/?action=view&current=dyno.jpg" target="_blank"><img src="http://i253.photobucket.com/albums/hh41/1badriv/455/dyno.jpg" border="0" alt="Photobucket"></a>

 

Nice Yardley, nice fix with Just the intake. Was this on Joe's dyno? You gonna run it Sunday?