Hi,I am looking at ported heads,but not in the distant future. I read that even with 1mm oversize valves, 15rwhp is what you will probably gain like the dyno SuttonHp did with the FRPP ones(no oversize valves). If I have CAI,Tune,UDP's,CMDP's,Full Exhaust,and Cams, is there 30-35rwhp gains expected from them, or just 15rwhp?

 

Larger valves will result in more air flow and additional power IF and ONLY IF the edge of the valve does not come so close the chamber wall that it makes it difficult for the air to get past it. This condition is called valve shrouding and must be avoided. I am not familiar enough with the heads on the 3v 4.6 to know if using a 1 mm oversized valve will create this problem but judging by the increasing number of suppliers that are doing this with good results I don't think it's an issue here.
I'd say go for it, but to get the most benefit you should be running better than stock cams and long tube headers and a good intake to get the full benefit. The amount of gain will depend on your other mods.

 

281GT-I was just wondering if this only 15rwhp gain was true or not with Full Exhaust(Mid-Pipe,LT's,Mufflers), Full Bolt On's(UDP's, CMDP's, Gears, C&l Racer, 93 Octane Tune), and cams, or not. FoxLake dynoed their heads at 28rwhp which seems possible.

Tillmanspeed- since you are selling 1mm oversize valve heads do you think 35-40rwhp is possible if I already have what I said above when and if I buy heads?

Have you determined if valve shrouding is not an issue with your stg. 2 heads?

 

Also, if I buy those heads,I will have Full Exhaust,Full Bolt On's,and Cams. I already have Full Bolt On's,as you can see in my signature. I just need cams and longtubes to make the gains from the heads better. Going with a GT500 TB after I get LT's and Cams should give alittle better breathing then the stock one without causing trouble codes.

 

I have not had any issues with the clearances between the valves and the chamber, how ever I have been following the issue since it started a few years back on some of the 4v's locally.

After we get some test results from the flowbench, I deal with a local shop that has an engine dyno. I'd really like to get some comparisons. I will tell you that 35-40RWhp is a stretch until you get a S/C. You will see 2x better results under psi.

Exactly as Carlos said above, it's about the whole package. The TB, LT's, and Cams will put you at your mark for sure plus much more.

CR
Tillman Speed
610-497-3711

 

When you say that with LT's,Cams,and TB,I will meet my mark,do you mean I will get the 35-40rwhp from your stg. 2 heads if I have those mods before I get the heads?

 

Well I am shooting for 380-385rwhp with:
C&l Racer
93 Octane Tune
UDP's
CMDP's
American Racing 1 5/8" LT's with Catted H-Pipe
Stage 3 Comp Cams
GT500 Throttle Body
and your Stage 2 Cylinder Heads with 1mm oversize valves

 

Yeah I alos am in he same boat.. I Do have the JLT II, Steeda UDP's, CMDP's and Hooker LT headers already installed. Comp cams stage 3's have been sitting in my dinning room for about 2 mnths now. They should be installed by the end of June or mid july. I am thinking the heads will be the big project for next year. I still want to get some of those Rotorpro's slotted and cross drilled rotors this summer if possible. The only other bolt on I am considering is a lightweight drive shaft. I'm sure Cr can hook me up w/a great price if I decide to go that route.

 

I am only 1 step behind you as in installed performance mods.(I don't have headers)

 

Rafael,

We'll take care of you on the driveshaft for sure!

mustangfan... that number isn't too far fetched. To be honest, I'd feel more comfortable if you brought it down here to tune.

 

Now THERE'S a TRUE enthusiast. Performance cams sitting on the dining room table. I gotta respect that!!! No get them OFF the table in IN the car!

To the original poster. I forgot that with all those changes a larger TB would become neccesary. I think with all those changes though you could see a 25 - 30 hp gain.

 

Thats a pretty lofty goal...I would say under perfect conditions you might see 360 to the wheels. I just don't see 30rwhp just from heads - but if you paired the heads with cams I would say thats more than capable.

If I was your parents I would just go with the full exhaust then throw on a blower at low boost, because even though everyone loves to think this motor will make good power N/A - The truth of the matter is, its not the LS1 and you will see a way better bang for buck by just going with a blower .02

 

I hope I can still get 380rwhp someday with those mods dynoing it at a performance place nearby me since your shop is too far.

 

You didn't see I paired heads with cams in my mod list to get 380rwhp?

 

you really should have seen my room back a few months ago. supercharger on the floor, headers on the desk, intake and carb on the floor of the dining room, toolbox by the foot of the bed. People think im crazy

 

Definetly need the cams to hit that number... absolutely no question.

CR

 

Yep thats for sure. Lets see where I am right now hp wise. With C&L Racer,93 Custom Dynotune,Udp's,and CMDP's, I am at 293rwhp. Add headers,and they should add about 15-20rwhp,which puts me at 310-315rwhp. Then get cams and I should have 340rwhp.Get GT500 TB so now I am at 350rwhp. Finally add ported Heads which puts me at 380-385rwhp,the magic number for me.

 

Ha hA ha!! true.. the reason I had put off the install was I was thinking of doing the P&P heads while at it... although at this rate it will take me all summer just to save up for the heads, install so forth. Plus I recently had electric exhaust cut outs installed and when they are open you can hear the stock cams so now I cant wait!! Those cams have to go in soon!

 

Ok i have a question... my friend who is going to install the Cams says while he's at it he can also work on the heads. He says he can P& P the heads, as well as blend the combustion chambers and polish and lap the valves. Now I already have a set of upgraded springs and retainers for the stage 3 cams. Do you think it would be worth trying. Also, would I need an updated tune for the extra amount of air that flowing right after the install? I plan on taking it to a dyno shorty after the install and eventually I will be having a custom dyno tune done anyways. I guess my questions are, should I let him take a whack and the heads and if so.. would I be ok with the tune I have now until I get that custom tune. Let me know what everone thinks. Thanks!!

 

I did see you paired heads and cams, I just don't see you making 45+ to the wheels, which is like 70-80hp at the crank with only heads.

Your adding 25rwhp for cams and 40-45 more for heads, when what you need to be doing is adding 40 for both cams/heads put together which puts your parents car right around the 360 mark like i said earlier.

And just for the record a Brenspeed canned tune isn't considered custom. You will however need a custom tune when you start digging deep into the engine