2.4L Headwork

[TurboBuggy]

Hey all, Im building a 2.4L turbo engine using the engine out of a 97 stratus. I bought a brand new DOHC head on ebay (Casting# 4667086). I want to work the head a little to get the most I can out of it without sending it out to a shop.

I was thinking about cutting two grooves into the combustion chamber squish areas (somender-singh grooves), and then polishing the combustion chamber and exhaust ports to a mirror finish.

I heard that polishing the intake ports is bad because it reduces turbulence and porting the exhuast ports is bad because it decreases velocity, what do you guys think? Should I port match the intake and exhaust ports? Any tips on what I should do to the head?

[Frank]

Please dont cut grooves... that technique is bogus... big time.

Your best bet is to just clean up the castings and such. You will get great results just by doing that.


Frank

[TurboBuggy]

Ive heard it reduces detonation, I was reading a thread somewhere and a guy said he grooved his head and it reduced knock alot.

Im shooting for 400-500Hp

[Frank]

Then a mild port job isnt going to work. Talk to INDY heads... you will need their large valve big port job. 315cfm capable heads.... which is the route I am going.

I have been thru the site that has suggest cutting the grooves. There is alot of things on there that give me grief... never a back to back test, indistiquishable results on most configurations, amoung other things. In addition, his theory and reasoning for the practice is completely wrong. The fact that he (the inventor) has experienced some results on that Briggs engine was interesting, but even then it was quenstionable.


Frank

[Speedeuphoria]

Then a mild port job isnt going to work. Talk to INDY heads... you will need their large valve big port job. 315cfm capable heads

you don't need more than a mild port job for 400-500 horse power. This is proven by Kevin Davis who AFAIK only cleaned it up and took down the humps

[Frank]

Kevin Davis last I saw is not running near high 9second 1/4 miles. 500chp is much more intensive then 400chp which is already hard to run and equals high 10s to mid 11s depending on the weight of the car. Yes it could be done, but we will see what the fustration level is achieving it without NOS.


Frank

[TurboBuggy]

how much would porting like that cost? I was hoping to get around 400hp and then gradually get up to high 400s - 500hp running methanol/water injection instead of an intercooler. Maybe im setting my goals too high, I didnt think 500hp was so hard to get out of these engines. What kind of boost levels would I be looking at for this power?

This is going in my 1300 pound sandrail, so I think ill do better than 9s 1/4 (if I can keep the tranny together) :eyebrows:

[Frank]

1300lb sandrail? Dear lord! That would be sweet! My suggestion then is to deburr and do some minor porting yourself and see where it takes you. Then when you can't go further, then do the full INDY port with big valves... runs about 1700. Since it is going in such a light car, then it is either to get more power from a bigger turbo because you are light....


Frank

[Frank]

Oh and since the nature of the vehicle, running lots of meth is easier... I would go with 9:1 compression.


Frank

[TurboBuggy]

you mean lots of meth in the alcohol/water injection? Higher CR would probably be a good idea, on my buggy with a 2.2 turbo I barely have time to get the boost up before I have to shift, higher CR would probably spool it quicker. I think there are 8.8:1 CR pistons available for SRT-4s, but I wonder how much boost I could run before detonation? I dont really know where to get pure methanol, I was planning on using window-washing fluid. I will be driving the buggy mostly on the street and dunes with an occasional trip to the strip.

[Frank]

I think a 9:1 compression ratio will still allow you to run tons of boost with proper fuel tunning... maybe 9.5:1. All I would do is clean up the chambers and ports with a dremel. That will help imensly.


Frank

[Speedeuphoria]

Kevin is going to run a 10 sec pass in the near future and the car weighs 3200lbs w/ him in it. He dyno'd it last year and was at 420whp on 20psi and now has it turned up to 27psi.

[Frank]

My bad. I didnt realize it was that good.


Frank

[Speedeuphoria]

I wasn't throwing it in your face(not that you took it that way), I was just letting you know.:thumb:
He has yet to get to a 1/4 mile track but is planning on going soon. He still doesn't have a cage so he is hoping to run at least 1 10 sec pass before they kick him out.
It is a well built car. I hope that mine holds together as well as his.

Frank while your here I was wondering what you had planned for your setup? Like what year 2.4 motor your using. I have found and keep records of much valubale info pertaining to these motors and I am willing to give you some info if you want(just little things/ tricks I have came accross and stuff I'm doing)lmk

[TurboBuggy]

Frank while your here I was wondering what you had planned for your setup? Like what year 2.4 motor your using. I have found and keep records of much valubale info pertaining to these motors and I am willing to give you some info if you want(just little things/ tricks I have came accross and stuff I'm doing)lmk


dude send that info my way too!!!

[TurboBuggy]

you don't need more than a mild port job for 400-500 horse power. This is proven by Kevin Davis who AFAIK only cleaned it up and took down the humps

What compression ratio is he running? And what humps did he take down?