Highest stock head redline - SRT Forums

ST3PH3N'S SRT-4 · 10-06-2009, 02:17 AM

Whats the highest redline you can run with a stock head? or should i say the safest. i have a built bottom end with an act 6puck clutch.

lyncoo · 10-06-2009, 02:25 AM

your fine to 7k i do it all the time

bene · 10-06-2009, 03:01 AM

stock valves tend to float around 67xx

thats about it though.

lyncoo · 10-06-2009, 03:05 AM

i have a dcr oil mod too, thats about the only thing i'll ever buy from dcr tho

**04blusrt_4** · 10-06-2009, 10:38 AM

My valves i think are floating around 6500-6600 according to my boost logs, I am seeing a pretty big boost drop right around there (2psi) which indicates overlap, or float. I don't have the modifier tho, which is my next mod.

The stock head will only flow so much, I dont really see the benefit of revving past 6500 unless you do some port work. Basically the stock springs start to float right around the same time max flow is reached on the stock cam.

ST3PH3N'S SRT-4 · 10-06-2009, 01:38 PM

I have the oil modifier so I'll see what happens at 7k. What's the worst that can happen ?

lyncoo · 10-06-2009, 01:42 PM

Quote: Originally Posted by ST3PH3N'S SRT-4

I have the oil modifier so I'll see what happens at 7k. What's the worst that can happen ?

nothing bro. when agp came out with the sct everybody was doing it

ive done it up to 26psi but thats the most boost ive ever ran

**04blusrt_4** · 10-06-2009, 01:53 PM

Quote: Originally Posted by ST3PH3N'S SRT-4

I have the oil modifier so I'll see what happens at 7k. What's the worst that can happen ?

Three things actually:

I am a firm believer that balance shaft chain failures are from high rpm, NOT just high power. I assume youre already built, so no problems there.

Next is you will simply over rev the stock head / cam flow area, and simply be losing power BIG time past 6500. Itll slow you down considerably.

Worse case scenario, you float a valve, piston to valve contact, end of head and maybe piston.

NemoFoss · 10-06-2009, 03:01 PM

Stock cams springs and valves are good to 7200 and will live to 7500.
They won't float.. At 7800-8000 the heads will snap off..
2 piece friction welded valves FTL.
Stock cams stop flowing at 5200 rpm Notice your tq peak almost always stops there..
Stock head with good cams will flow to about 6200 before flat lining, will make power to about 7000 with BC stg 2 or 3's
Been there done that..

**04blusrt_4** · 10-06-2009, 03:08 PM

Quote: Originally Posted by NemoFoss

Stock cams springs and valves are good to 7200 and will live to 7500.
They won't float.. At 7800-8000 the heads will snap off..
2 piece friction welded valves FTL.
Stock cams stop flowing at 5200 rpm Notice your tq peak almost always stops there..
Stock head with good cams will flow to about 6200 before flat lining, will make power to about 7000 with BC stg 2 or 3's
Been there done that..

this. Stock cams plus porting is not a bad combo either, but you might as well swap cams while your at it.

Dont necesarily agree with float, its dependent on A LOT of things, esp oil weight, mileage, etc. Valve float on a low lift cam profile like the stocker wont show any big powerloss i would guess.

bene · 10-06-2009, 03:21 PM

do yall recommend the oil flow modifier for revving past 6250?

i never knew what this did exactly

lyncoo · 10-06-2009, 05:15 PM

Quote: Originally Posted by bene

do yall recommend the oil flow modifier for revving past 6250?

i never knew what this did exactly

you can see a dip in your dyno sheet without the oil mod around 6200

lyncoo · 10-06-2009, 05:16 PM

just get a ragetek built head best mod i ever did to bad i parted out.

NemoFoss · 10-15-2009, 07:58 PM

I'll have to look at my dyno charts but I never notice any power dip at 6200. I never use oil restrictors..

lyncoo · 10-15-2009, 08:01 PM

Quote: Originally Posted by NemoFoss

I'll have to look at my dyno charts but I never notice any power dip at 6200. I never use oil restrictors..

maybe i explained it wrong. but im on stock exhaust right now and i fell it. never did when i was on 20+psi and fully bolted. im on 10psi right now