Hey guys, so i’m finally looking to slap on heads/cam and up the compression on my little stock bottom end LS1. I’m pretty set on the Streetsweeper HT (228/232 .612/.600 111LSA) along with the PRC 225 62cc with hollow valves and .040 cometic gaskets. Based off the calculators i’ve used, i should come in at around 11.3:1 compression, which is where i’d like to be. Now, i’m still learning all the rocket science lol so my question is, will i run into P2V clearance issues? Or will i have adequate clearance?

 

Should be fine. PRC 225s have a shallower valve angle than stock heads so they have better PTV clearance. I have the same heads with a 232/234 .600/.600 cam with a 0.045 head gasket, Texas Speed told me I could mill my heads another 0.018 (bringing the heads down to 59cc) with my setup and still have plenty of room.

Of course, as always, check before running it. But I don't anticipate that being an issue.

 

That’s good news. I was anticipating that i wouldn’t have an issue cause of the aftermarket cast but as you said, won’t truly know till i get in there and measure. I think i’ll stick with the 62cc and the .040 gaskets, targeting 11.1-11.3 compression. I’d love to mill them some more but we only have 91 octane here in California. Really don’t want to have to mix in race gas. Btw, i’m patiently waiting on the numbers from your setup!! It’s going to be a beast!

 

I ran a MS4 and PRC 215s at 60cc and cleared with a gm head gasket. The 215s are now on another motor with a Torquer 2 but stock head gasket.

 

What rocker arms? Have you thought about 1.8 rockers? Would definitely fill the cylinders. Would definitely have to check piston to valve clearance and likely only see them close on the intake. Easy enough to relieve the pistons still in the engine with the right cutter.

 

Unfortunately, I'm not sure if I'll ever get dyno numbers. I ended up using a remote tune through Pat G because of various reasons, I had hoped to get a chance to get a couple hits on a dyno this last summer but it just never panned out.

However, with a DA of about 3000', on worn street tires with an awful 60 ft, I did manage to trap 119.84 mph at the track. I also pulled (barely but I still pulled) on my friend's C6 Grandsport with a Kaotik cam, headers and X-pipe from a 40 roll, and I stay door to door with another friends P1SC + header/x-pipe C5Z. So I would say it does pretty good.

 

Stock 1.7 rockers and no, i haven’t considered different rocker ratio. I’ll look into it but would rather avoid flycutting. Already pushing the budget with the cam, 225 heads and fast intake lol. Just got done with my suspension, clutch and a bunch of other stuff. The mod bug got me bad this year!

 

I essentially did the same set up, but with TFS 220’s and the original Streetsweeper. I was close to safe minimums on PTV but I’ve been bouncin’ it off the limiter for a couple years no problem.

91 is marginal at best at 11.3:1 with a good tune, I still get knock occasionally. Bumping compression any further with **** gas is probably an exercise in futility.

Sounds like a good set up

 

Buy once cry once.

 

How did you like the MS4? Pretty similar to the MS3 and that was my second choice behind the Streetsweeper. I’m still considering it. Figure a nice bump in compression and the 225 heads would really wake up the cam.

 

I also have the PRC 225's 62cc chambers in a flat top (no reliefs) LQ9 with the TSP v4 231/234 .629" .615" 111* and no PTV issues with limiter set at 7000.

 

I liked the MS4. It destroyed a couple sets of valve tips but looking back I wasn’t much more than a teenager at the time and didn’t check the wipe pattern. It drove good for what it was it’s just been a while since I’ve had that set up. It peaked at 6900 with the 215s and fast. It went 10.92 at 126 with a T56 and basically full weight. I didn’t tune that car but I did tune MS3 T56 car and other than creeping in a parking lot it drove like stock. Rolling above 1500 in 1st you’d never know it was in there.