Got off the phone with Tony and I guess I'm going to be the next Guinea-Goat for his 220s. My car has been very strong since my stroker build last year but I knew my heads were holding me back. I'll be getting the 220s and a cam spec'd for it and we'll see how the goat responds. It's going to be a few weeks but stay tuned.

 

What top end does it currently have?

 

Some ported 243s. I can tell by my butt and my VE table that drops off after 5,600 that it's gasping for air on the top end

 

That's not good! Those heads on a 383 should be very potent I'm thinking. I'll be curious to see how this turns out

 

What kind of power is the car making now ? Current cam specs ?

 

 

Those heads will kick *** on your 383" what are your current cam specs?
I'll bet your next cam is close to 235*/239* .610"/.590"
114*+2*

 

When the butt-meter AND the VE table tells you things are signing off its not good....LOL

Looking forward to working with you on the build.....you will be the first 383 combo with these heads which is exciting because I think they will do extremely well on the small bore extra stroke/cube situation. Send me the intake!!....LOL (Pier pressure now! )

Got the paypal and all your info before btw.....thank you

Regards,
Tony

 

Never put it on the dyno after the stroker build. With mostly the same parts except the stroke and cam I was making 440/409 before. The increase in power was very noticeable, not just a "maybe my butt feels a bit more" but "holy crap" after the build. It took quite a bit more fueling and I could really feel the torque. I run a speed density tune and my fueling falls off big time after 5,600 though. I had a similar but slightly smaller cam before so the difference is the air the extra 37 cubes are calling for. Current cam is 229/236 .631/.631 111.

Depending on when it gets done and the weather I'll get a dyno run in on it. Last summer I built the engine and by the time all the delayed parts and my old slow *** got done it was the middle of October. I got to drive it two weeks and then we got slammed with an early winter and away she went to sleep until spring.

 

What does your VE table look like in the higher rpm?

 

Did you guys talk about the bigger Mamo heads?

 

It drops off 10% 5,600>6,400 on up. On the 346 it carried higher and only dropped off 5% from peak all the way up to 6,800

The bigger heads won't fit my bore

 

I like to stay up on the 383ci builds to see the general power potential everyone is getting out of theirs. I reused my heads/cam from my 347ci build and I know my current cam is on the small side for the 383ci. Bigger headers and cam is on my list of "to do's" when ever the kids stop spending all my money.

Thanks for sharing, in for results...

 

I'll be interested to see how much duration etc Tony chooses on this setup. Should make over 480 to the tire easily and plenty of low end grunt to boot.

 

I thought I read the bigger heads would work with a stock LS2 bore???

Edit: Here is something copied and pasted from Tony's thread about the MMS 235cc heads.


The 235's are naturally aimed at larger displacement (a perfect choice for a street/strip 416 build), but this head would also be right at home in an aggressive 6.0 liter build if the focus was on max power. A 220 is still a better head on a max effort 5.7 liter having enough size and CSA to feed it, but the larger bore of the 6.0 and the additional cubes would make the 235 a workable situation in an aggressive build. Honestly the right head on a 6.0 (220 vs 235) is really the nature of the build and how aggressive a build you plan on because you could make an argument for one or the other purely based on application and the way you drive it. I would say the 220 is really a better head on that displacement 75% of the time but if your flycutting or going aftermarket pistons, pushing the compression limit on pump fuel, and getting aggressive with the camshaft, the 235 would be the right call for a stronger 4500 to redline pull on a 6.0 or larger combo.

The MMS 235 will prove to be very versatile because while close to the size most ported OEM heads finish at, they flow a solid 20 - 40 CFM better so the airspeed is good and that's what will help it to work well on the smaller displacement stuff while the 340+ CFM's of peak flow will comfortably feed a 400+ CFM stroker and on that size engine, a 235 is modestly sized and will produce incredible throttle response while still providing enough airflow to comfortably make over 550 RWHP (more in a well sorted out optimized combo).

 

I'm think the motor is a LS1 5.7 since the op is going 383.
All GTO cars didn't have the bigger bite 6.0 LS2 motors. If it was a 6.0 LS2 stroked it'll be a 402 roughly....

 

Ah, yes, brain fart on my end. You are correct. I apologize OP.

 

I would bet higher than that, depending on how far the OP is willing to go on the smaller items. UD damper, meziere, light clutch, duals, etc. it all adds up.

The thing is that Tony likes to keep the cams moderate for decent drivability, but the longer stroke can absorb more cam. A 235/240-ish cam in a 383 with those heads should still drive quite well, and with the added overlap from to help carry power and RPM's, I'd bet in the 520 range at the wheels

Tony was concerned a bit by the 8 degrees of overlap in mine hurting the throttle response and partial throttle power, but it's pretty damn strong IMO. With a 4" stroke, 12 degrees should be easy to tame in the tune.

 

Heavy car guys.....the 220's are perfect in this (mainly street) application even if the 235's would fit.

They really have enough cross section to work well on a 383 and plenty of CFM on tap as well but its an excellent choice for this build cause it will help build some low/midrange torque (more important in a heavy hot-rod) and also add to the overall responsiveness of the package.

We are likely going to run a 235/240 on a 113 LSA but Im waiting on some word back and more feedback from the OP. That should have similar manners to the cam he was used to but help make a bunch more power with the additional duration and later intake closing of the wider LSA.

What you felt was the extra TQ down low more than anything else. Keeping the same "lungs" and valve events similar (lungs meaning your heads), a bigger engine will only make more TQ.....not more HP.....and it will make the similar power figure at a lower RPM than the smaller motor it was originally set up with. And it will roll over faster because the bigger engine is out of breath faster with the same flowing heads....larger cube engines place a higher air demand on the system. If you cant afford a good set of heads don't bother investing in a stroker....not if your trying to make more power (I say this to all reading....not aimed at the OP).

But back to the OP, if you think about what you just said/typed above, it backs up my statements to the letter. Had you dyno'ed the last combo you would have seen a 35 ish ft/lb increase in TQ with the peak RWHP very similar to the 346 set-up but happening at an earlier RPM (the larger motor taps out the available airflow sooner). However, you would have picked up more average power due to having more area under the curve and alot more bottom end.....all of which you obviously felt in the butt-meter, but the falling on its face you also felt was the fact the top end of the curve didn't improve and it felt even more lethargic in comparison because you picked up so much down low.

Had you taken both to the track it wouldn't have ran much better (horsepower dictates track results....not improvements in TQ) but the bigger engine is much more fun on the street with all the extra bottom end grunt for scooting around town.

The new deal is going to fatten everything and it will be a whole different ball game past 5000 RPM's now....the engine's new appetite for air/RPM will impress and it should pull strong with authority to 6800 or so without feeling like its laying down at all (it will of course nose over but happen later in the curve with a much smoother, slower roll off).



-Tony

 

in for results, as i'm going 383 stroker ls1 on my gto in the next few weeks.
already have ai 219cc heads and ms3 cam, so in for more details. will be
changing the cam out as well. already have an elec pump, udp, fast 92, blah
blah, blah...