Swapped to CC 978 springs per TEAs recomendation. Power still dies after 6K. So, after buying a new short block, four sets of different length pushrods, two sets of lifters, four sets of springs, three sets of rocker arms, and tuning, I have a motor that can't rev past 6k.

Someone please explain to me why I'm still spending money on this car.

 

Not enough information to help out here.

Who installed the top end and verified the correct valvetrain geometry?

Who tuned it?

What's you're fuel pressure at 5800+RPM?

Is your fuel filter clogged?

Are you getting KR?

Do you have the dyno sheets to post?

What was your AFR on the dyno?

 

Doesn't sound like valvetrain is your trouble bro. Seems as though you're taking shots in the wrong direction.....

 

Top end-set up twice by Rapidmotorsports, twice by me with same results

Tuning by Rapidmotorsports

Fuel pressure was low prior to fuel pump install-not sure if Rapid checked it when it was retuned

New fuel filter

No KR

No postable dyno sheets. Curve is dead on, hitting 420 at 6000rpm, then the power drops straight down

A/F was between 13.4-13.9 I hooked up a MAFT and added fuel today and it picked up a little power.

 

I would ditch the Comp Pro Mag rockers and go back to the stock rockers.

Jason

 

Two of my last four dyno sessions were done with the stock rockers. The curve looked the same, but was a little lower HP wise.

 

I am having the same problem with my car as well... New springs (978's from 987's) and no dice. TTT

 

Is the cam installed dot to dot? and have you had it checked out to make sure it was ground correctly?

Just some ideas but I am sure you checked these already

 

Not to highjack his thread, but I know in my application the cam was installed Dot to Dot.

 

Same here. I followed a post from Verbs awhile back where he had the identical situation with TR230 and TEA heads. I'm not sure if he found the issue.

 

Any chance this could be an issue with the heads? Would issues with the valves/valve seats cause this?

I'm running out of things to check.

 

Did you ever verify cam timing as I eluded to in your previous thread?

 

Aftermarket rockers can fatigue springs that are borderline as far as the amount of lift they can handle.

Your 1.75 rockers up your lift on your TR230, and if they weigh more on the tips of the rockers, it could help induce valve float.

First go back to the stock rockers. If that doesn't work my guess is you didn't get enough spring. I even had Comp 832 dual springs good to .650 lift which thunder racing said would be perfect for my G5X3 cam....boy were they wrong.

You can't just look at the manufacturer rated lift capabilities of a springs, you need to look at seat pressure too. I ran into problems with the Crane 832 duals because they lacked seat pressure.



I also ran into problems with Com 987 dual valve springs with a TR230 when I put Yella Terra rockers on there....the extra weight on the tip induced valve float since the 987's were being pushed close to their max lift as it was with the Comp 987 springs.


Now, you mentioned that you tested it with and without the aftermarket rockers.....so maybe it's fuel? You seem to be pretty lean....