Mark924S

Maybe I missed it but would an NA block be alright to use for a stroker build?
also were you guys using the 8v NA heads on the 2.85s?

refresh951

Later NA block is fine - 87-88. (Earlier have thinner cylinder walls or no auto tensioner)

We used 951 heads on the 2.85L

V2Rocket

Shawn,
How does the 3.12 perform between 1000-3000RPM? Is it a dog like a normal 2.5 or does it get up and go, even before the boost comes on?

refresh951

At 1500 rpm my 3.12L makes more torque (about 140 ft-lbs) than my NA at any rpm! Compare the dyno with other 3L cars and you will see what 95 mm of stroke does for the bottom end! For a street car it is special.

V2Rocket

woooo

140ftlbs at 1500rpm, or 140 MORE ftlbs than an NA?

travisgreen

1500 rpms......

refresh951

I might have understated a bit, more like 150 ft lbs at 1500 rpm My NA has about 130 ft lbs MAX at the wheels across the whole power band.

V2Rocket

i was gonna say..what kind of tractor is this??
mine shows 133 max wtq with NA-tune installed and no other mods

blown 944

I think a great combo would be a 95mm stroker with a gtx30. For a daily driver, it would be just flatout fun. Shift it at 6000 rpms and enjoy it. If I get tired of chasing big HP with these cars, that is exactly what I'm doing. I could imagine 300plus wht from 2200 rpms.

Depending on how far I get with the DSM this year, I may go to a smaller turbo. However, it's been a little while and I'm hoping my 3.0 will spool my turbo around 3500 rpms. I remember my last combo seemed to just tear the tires up as the torque came up.

my last dyno that corresponds to appx 125 in the quarter

blown 944

Actually the 86 blocks are ok too. The early blocks are a little thinner, but can still be straight sleeved (my last engine was an early block). My current 3.0 is an NA block.

refresh951

And this is a 2.85L, very impressive. You can definitely see the near 86 mm stroke on the bottom also.

Good to know.

Mark924S

that was what I was hoping to hear! the NA block I have is an 87 auto tensioner. I've heard of some of the guys using the NA head with different valves saying the NA valves can be ported to flow more on the exhuast side. With more displacement is that a better way to go or is it safer to stick with the 951 heads? Sorry to keep badgering you guys with the questions, just want to pick your brains!

blown 944

For most engines, I'd stick to the 951 head (as far as exhaust goes). The exhaust flows very well already. I will find out this weekend what the stock exhaust can do with a few small mods.

Either way, you want the ports ceramic coated at the very least. I've tried an NA head, and it certainly slows the spoolup.

refresh951

Please observe all safety practices.

blown 944

:-0

I just can't lol that one. Even though I'd like to.

No this will be on a superflow. If we can though, I'd love to do a comparison test between the benches.