Breaking up

No rev limit as I use alky for chemical intercooling on the stock coil pack. The TR6 isnt set up for anything as of now.
What should I look for? cracks? wear?
As far as wear the reluctor can rise up and make contact with cap if bushings, etc in the cam sensor shaft is worn. There will be clear witness marks on the inside. Side note im actually chasing almost the exact same problem at 5800 and I have TA SI heads.
 
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Thinking that the crankshaft position sensor might be suspect. Worth having a look at the sensor and it's wires. See if the sensor hit the interruptor wheel.
 
14.5v throughout a 3rd gear pull
roller cam 214/214 .548 lift with 1.65 T&D roller rockers
Preload is .025 -.030 and I bought new length push rods They came out to like 8.80IIR
What lobes are those? I'm getting .332" lobe lift. Doesn't ring a bell.


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New TR6 didnt solve it either..... this confirms my coil pack testing.It is much better, but still has a little breaking up. I kept the plug gap at .020 but I really dont think that would have anything to do with it.
I watched FP rise and stay where it needs to be. Valve springs are 150psi and new along with the whole head assembly. I just dont know. Maybe a bad plug?
I have the non resister plugs still laying around.

My heads came set up at 150 on the seat from TA. I talked with the owner questioning this and he told me that's not enough spring pressure for my cam. He said shim the valve .060 so we did. My builder had already done that on the intake side but I had him shim the exhaust as well after talking to TA Performance. I think I'm closer to 180/190 on the seat now and should be high 3's low 4's open.

I rode in Bo's car when it breaks up and it's violent. Not sure if spring pressure could cause that much break up or not. I've never had spring pressure issue's but it's like someone turned out the light switch. I would have guessed ignition too but maybe someone has had the same issue with spring pressure resulting in a on/off type reaction. Didn't act like valve float to me but his motor revs like a 2 stroke weed wacker so it's from 3000 rpm to 5500 rpm right now.
 
If its completely cutting out that makes me think even more that it could be crank signal. If it is crank signal though, it will be readily evident in a data log. The RPM and injector pulse will just drop right out when it happens.
 
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With the TR6, it is a subtle cut out. Im going to change back to the old plugs tomorrow. When Brett rode in the car, it was spark blow out. I had it running great and didnt start the car for 2 weeks, then take it out and it breaks up.
 
Before when I had valve float at 6k rpm, the car would spin the tires for 30ft then stop for 10ft then spin for 30ft ect. I didnt change cam, just heads.
 
What springs? So the breaking up is getting worse, and at lower rpm?
I was just cruising through the post. I thiught i saw somewhere that you were using comp 941 springs, which are not enoigh for that cam.
 
TA did the springs. All I know is 150lbs. I talked to Nick about this because I thought it was a little low, but he assured me they were ok to 5800-6k rpm.
The breaking up is always been 5k-5200 rpm and it is better with the TR6.
 
150lbs on the seat isn't anywhere near enough for those lobes if you plan on having valve control over 5000rpm. Also your theoretical lift is .584". You will be struggling with coil bind trying to get enough pressure. The only spring acceptable for a stock length valve and those lobes with a 1.65 rocker is the PAC 1203. They aren't an easy install either. For that type of lobe I'd want 170-180 seat minimum with a 1.55 rocker. With a 1.65 rocker rpm will be reduced 200-300 more. I wouldn't recommend 5/16 pushrods with them either. I also wouldn't trust spring installed heights and pressures unless you measured them yourself. I've had at least 10 sets of heads come through with no where near the correct spring pressure in the last year alone. Some were likely mistakes where flat cam springs were installed on heads for a hyd roller and others were just bogus spec sheets that weren't even close to the heights/pressures listed. Several were also unknown. It's like reaching into a box of turbos and not looking at what it is exactly and bolting it on your car. Everyone knows what turbo they are running but most have absolutely no clue about the valvetrain stability whatsoever.


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I am pretty sure it is the 214 full throttle sells, xfi lobes.
Those have more lobe lift than he stated he had but the card is showing much more than he stated also. This is about equivalent to what you had in your fast car!


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Did anyone else notice that the cam card states it is an 'odd fire' cam? If true...

Maybe a typo?

RemoveBeforeFlight
 
Looks like beehive or conical springs are the easiest choice without machining rockers since 1.385 OD springs are the end of the world with TA heads and T&D rockers since any larger will hit the rocker arms and require machining, etc. Of course the swap to the different springs will entail new retainers and new locks since the degree will change with retainer swap. No intention of hijacking but as i mentioned earlier im chasing a similar issue and having the strongest springs that TA sells and still has a stumble at 5100 5200 and breaks up at 5800ish. I have been doing research on further upgrading springs and it seems conical or beehives are the best choice since I just cant swallow machining my rocker arms after paying 700 bucks for them.
 
The old combo had 1.6 rockers and same cam with 941's. I could go to 5800-6000RPM Anything after that was valve float, but the car ran great at 5800.
 
The old combo had 1.6 rockers and same cam with 941's. I could go to 5800-6000RPM Anything after that was valve float, but the car ran great at 5800.
So you had a 140mph car?


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