capn smokey

iTrader: (1)

hey guys I just bumped my car to 11:1 cr by putting on a new set of heads, they are iron rhs 200ccrunner heads. I know 11:1 is risky on pump gas with an iron head but it seems to run fine right now but definitely has a lot more in it. What would you guys suggest me to set my timing at to avoid detonation? My fquick page has all the info on my setup in case you are wondering. Any help would be greatly appreciated.
Thanks-Jeremy

9000th01ss

iTrader: (10)

I've run all iron 1st gen small blocks with vortec heads at 11:1 with 32 degrees. Even with 89 octane. The dynamic compression ratio is what matters most although I did run this same engine with only a cam swap. Had one cam give it 8.4 DCR with no problems, ran another at 8.2 DCR and it didn't like the 89 octane. This was with dome tops and a .032 quench distance.

ZONES89RS

iTrader: (25)

Yep, 32 is what i was goig to suggest, my aluminum heads will allow me to go 34-36 i hope.

Cali99SS

iTrader: (1)

Well my timing is astronomical then. I'm only at 9.5:1 but my total timing is 43. Iron eagle platinum headed SBC. Maybe dynamic is kinda low? bigger cam.

capn smokey

iTrader: (1)

Went out and did some "testing" tonight, apparently my motor likes 41 degrees total. Go figure, I dont know why it takes so much timing but at 32 degrees it was door to door with my buddies bol-on LS1 camaro and at 41 it killed him. I ran 2 cars that both trap 118-120 and won against both of them, I guess that bump in cr made a huge difference. I trapped 110-112 on my old setup and I would guess Im at 118-120 now, I was also running half a tank of 110 octane tonight though. To say the least Im very pleased with these rhs heads, they are straight out of the box with no port work and I would guess they are supporting 450+bhp. Thanks for the input guys.
-Jeremy

ZONES89RS

iTrader: (25)

Jeremy, higher octane will hurt performance in a low compression car, that night yyou should have stuck with regular fuel.

capn smokey

iTrader: (1)

What are you talking about? I ran 89octane on my old setup but now I run 110, I was hoping I could run 93 with these new heads but it loses about 50hp unless I run 110. Im going to the track tonight, Ill try to get some video.

ZONES89RS

iTrader: (25)

I thought you meant the old setup you ran 110 once at the track, my bad.

RAGENZ28

iTrader: (5)

11-1 on a sbc with iron heads shouldn't run on pump gas. I would at least blend it with some race gas and 93 or 91 whatever you have out there. With blended gas I would run 34-36*

ZONES89RS

iTrader: (25)

I should be right on the limit with my aluminum heads i think.

RAGENZ28

iTrader: (5)

Most I would go on a sbc with aluminum heads on pump gas is 11-1 with a good size cam.

ZONES89RS

iTrader: (25)

242/252 @.050 on a 112 good enough?

kenSS

iTrader: (1)

my timing is set at 36 with 11-1 and iron heads.

RAGENZ28

iTrader: (5)

That's a good street / strip cam on nitrous. One in our 406 is 282/290 @.050 .7xx lift on a 112. We shift it at 8,400

ZONES89RS

iTrader: (25)

Street strip and a little hit of N2O is the plan, i think it will go 7000 RPM.