Gravedigger1

iTrader: (1)

I have a ly6 block l92 heads v jr intake msd 6012 ign. cant seem to get the rpms over 6,000 it doesn't hit the rev limiter i have set at 6900 it is not missing or anything like that itjust seemsto stop pulling at that rpm.it has a pat g cam in it and he said to set the shift point at 67-6900 rpm any ideas would be great

ZONES89RS

iTrader: (25)

Drop the rev limiter to 6000 and see if the tach drops to a 5000ish to stop pulling, you may have what several experience, the tach simply doesnt keep up with the engine.

Pop N Wood

iTrader: (1)

Good idea above.

You can also run the motor with a lap top connected and read the RPM from the ignition software.

Gravedigger1

iTrader: (1)

checked the tach it is reading right any other ideas?

GC99TA

iTrader: (30)

Don't mean to insult you, but still have to ask: Did you swap out the valve springs from the stock ones? I know you said it doesn't break up, but still could be valve float.

What are the cam specs?

3pedals

iTrader: (3)

if you have plugged in 1 of the timing chips at any point after setting the rpm limiter, then the timing chip may have reset the rpm limiter back to 5500. check it out.

Gravedigger1

iTrader: (1)

I have the 660 lift springs in it cam is a 635 lift pat g speced cam he said to shift at 67-6900 rpm it is weired climbs to 58ish and staysno missing or anything.I have not pluged any chips in after downloading a program. How can i plug my laptop in and check to see what program i put in? Sorry for stupid ?'s but i am new to this(not old school small block and 6al msd stuff)

Nosinfected70

i had a problem like this years ago after i changed out my roller lifters and ended up being the lifters were .100 thousands longer causing the same thing you describe or the springs need matched to your cam

Nosinfected70

pushrods could be to long also causing valves to float

Gravedigger1

iTrader: (1)

ok here's my whole set up that pat g and geoff told me to run 213/239 598/610 110 lsa plus 4 1.7 rokers patriot 660 duals tit retainers .045 commetic gaskets 7.45 pusrods

GC99TA

iTrader: (30)

Hmmmm. Assuming your intake duration number is a typo and you meant 231, that is the same cam he spec'd for my LY6, except with only 1 degree advance. Anyway, I haven't installed mine yet nor have I done any measuring, but I think 7.45 pushrods may be a little long. He recommended 7.425 PR for my set up with the same cam and I have stock thickness head gaskets. So, if anything, yours would need to be slightly shorter, not longer. Did you measure your required PR length or just install what was recommended? It's very possible that was a typo on his recommendation. I plan to measure first, but expect 7.4s will be long enough for my set up. I'd go back and check with a measuring tool if I were you.

Gravedigger1

iTrader: (1)

2 typos sorry 231 and 7.425

GC99TA

iTrader: (30)

OK...that makes a little more sense then. But, like I said, you may not need the extra .025 of PR length that the 4.725's provide (especially with your thinner head gaskets).....but the only way to know for sure it to measure. I asked Geoff why they recommended the slightly longer PRs for my set up, thinking maybe it had to do with a lower base circle on the cam. IIRC, Geoff said they just like to run a touch more preload....but that "touch" MAY be too much with your .010 or so thinner head gaskets. Just one more thing to check because it does sound like valve float to me if it just stops revving at a given RPM.

If it were breaking up really badly, I would be thinking more along the lines of an ignition problem.

Gravedigger1

iTrader: (1)

OK so i redid a program and downloaded it it ran funkie so i put the #5 pill in it and in park i reved it it ramped to 6400 spot on but in gear it dosn't seem to pull so i am thinking trans? it has a 400 turbo rev valve body man shift with a pro brake and a tci 9"4,000 stahl