[RandoGT]

ok, so if i port and polish a set of PI heads, how much HP can i expect out of that job?

also, on a side note, if i buy a new 4.6L block and i get it bored over a tad bit, does that increase HP? or what does that do exactly?

[TheUNZippee!]

It increases the volume of the combustion chamber to allow more air/fuel in to the cylinder. Boring alone is a minor increase in power. It's one of the many small things you do that add up to bigger gains. Porting and polishing is worth more power, how much I'm not exactly sure, as it varies on the head type. I'm sure the guys in this section who are more familiar with the PI heads will be able to tell you that part.

[Boomer]

Boring the block will increase the compression ratio allowing more air fuel to be entered onto the cylinders, making more power. This will also unshroud the intake valve helping the power as well.

Depending on the combination you can expect to see results of 15-25 N/A and more on a blower/turbo combo.

I do my basic potwork for around $400-500, multiangle valve jobs are a little more as I send it out for that. I have only found a couple of Cfm in a multiangle grind, most of the jobs I do are for N/A combo's.

[droppedbass87]

hey boomer do u port and polish heads???i need some more my forged engine thats im boosting...

[RandoGT]

what are multiangle jobs? and are the 15-25 HP gains with boring or P&P? also, could you give me a a price for a P&P job? just to compare it to a shop around me that does it

[Boomer]

Yes I do porting, boosted or N/A I can make the number happen. The 15 to 25 is just from my standard portwork N/A, I can't always gaurantee what gains will be made as there are to many variables, noone can make a promise only give an average.


Multiangle valve job: Is grinding the valve seat at 2 or more angles. This is done to transistion the air moving to or from the bowl area of the head around the valve and into the chamber.

I only do limited work, my starting cost is $450 and goes up from there. What "my " basic work starts with, mild intake runner porting and shaping, exhaust porting and polishing, bowl work and chamber work, also all my heads recieve new 8 thread spark plug inserts.

[caintcatchmyGT]

Whats the difference in the porting if its for boosted or N/A? i am gona build a N/A Motor as strong as i can and the last thing i will do is Boost. so I am a lil confused on things

[Boomer]

There are certain things that can be done to a head to make it perform better for each application. I am not going to give away all the secrets to the universe as I don't hold them. Port shape, volume, CFM, Velosity and quench are some of the keys to making a head work for one application or another.




If you plan to boost down the road build the engine for it now, your not going to get the maximum combo n/a and boost it and see great results. One thing I've learned the hard way you can't have the best of both worlds, one or the other or between. Camshafts are the same, n/a, blower, turbo, nitrous, you have to select a cam that best suites your combo. Again if not you do it twice or settle for somewhere in between. I am not saying a car will lose large amounts of power, but a car will gain alot if proper parts are selected for the aspiration of choice.

[caintcatchmyGT]

When looking at pre assembled short blocks with forged internals, they ask to specify N/A or boosted application. how different are these blocks and is it that serious that the 2 are different? Would it just be like the pistons that are different or what?

[Boomer]

Shortblocks will have different pistons and even rod in some cases. I have built N/a engines with lightweight rods that wouldn't handle boost so well.

[96Snaker]

Boomer - granted it's what you do for a living, but you certainly know your stuff. I for one, say Boomer for Mod...

and he is exactly right when saying that you must first decide upon what aspiration you desire, THEN select the proper parts for said setup. Setting up for high N/A numbers then switching to a forced induction setup can be pricey, and time consuming, provided you do it the correct way.

Now to get down to serious business here fellas... 96Snaker needs one or more of you to throw a large chunk of change his way so his cobra can soon see 400 N/A hp (well, hopefully in a year's time).

[04GTAMPA]

We just did my 04 and picked up +48 RWHP. We ported our stock heads and dropped comp 270 cams on it. Dyno proven baby!

Contact ACmillr...

http://www.moddedmustangs.com/forums...er=asc&start=0

[Boomer]

Originally Posted by 04GTAMPA We just did my 04 and picked up +48 RWHP. We ported our stock heads and dropped comp 270 cams on it. Dyno proven baby! Contact ACmillr... http://www.moddedmustangs.com/forums...er=asc&start=0

35+ rwhp is not uncommon with the 270's, not knocking ACmillr but without flowing the heads it is guesswork. Do you have a copy of said dyno, before and after ?

[04GTAMPA]

I'm waiting for my "blessed" tuner to e-mail me the graphs.
See, they moved the shop and their dyno is not in yet, so he rented a dyno and he saved the files in his laptop, couldn't print, but I'm still waiting for the graphs...

The car went from 251 RWHP and 301 TQ to 309 RWHP and 312 TQ Corrected. Don't know what happened with the torque...
"Uncorrected" were at 319 HP 329 TQ and on the spray 426 HP 469 TQ

[04GTAMPA]

Now your estimated 35 RWHP with just cams, is that with NPI or PI heads? What would be the gains for each? Estimated of course...

[Boomer]

Not bad numbers at all, what other mods do you have ?
My friends 96 with auto put down near simular number thru an auto, his cam was a little smaller. 294/301 corrected, ported P.I , Hitech stage 2, a few bolts on's.....

[Boomer]

Originally Posted by 04GTAMPA Now your estimated 35 RWHP with just cams, is that with NPI or PI heads? What would be the gains for each? Estimated of course...

I picked up 35 tuned on my 96 from the cams on a P.I head and was on the dyno. After porting of the heads and tuning I was at 330/319 corrected.I have yet to test a cam that large on my npi's, I have to find a valve seal to stop retainer to seal contact, although lately I have not had time I may get around to it. I have to go thru all the bmw and volvo seal to find one to sit correctly on the machined guides for clearance.

[04GTAMPA]

Good deal.
I have full bolt ons and LT's with H and Magnaflows... 5 speed with 4.10's.
Diablo tuned with flip switch for N20 tune and that's about it. I will be changing my plenum to an accufab this weekend and still need to tune it better. I was at the dyno with my wife and our 14 month old outside under the Florida heat so we called it a day, and my stock fuel pump was bogging at top end and we know that there's more power to be squeezed. I will get a set of 24# injectors as well... I'm sure we can get more torque and a few more ponies. I'm very happy with the head work, so was the tuner.

[acmillr]

Originally Posted by Boomer Originally Posted by 04GTAMPA We just did my 04 and picked up +48 RWHP. We ported our stock heads and dropped comp 270 cams on it. Dyno proven baby! Contact ACmillr... http://www.moddedmustangs.com/forums...er=asc&start=0 35+ rwhp is not uncommon with the 270's, not knocking ACmillr but without flowing the heads it is guesswork. Do you have a copy of said dyno, before and after ?

Looks like I continuously guess correctly.

[Boomer]

Originally Posted by acmillr Originally Posted by Boomer Originally Posted by 04GTAMPA We just did my 04 and picked up +48 RWHP. We ported our stock heads and dropped comp 270 cams on it. Dyno proven baby! Contact ACmillr... http://www.moddedmustangs.com/forums...er=asc&start=0 35+ rwhp is not uncommon with the 270's, not knocking ACmillr but without flowing the heads it is guesswork. Do you have a copy of said dyno, before and after ? Looks like I continuously guess correctly.

Pm'ed you, guesswork can get us all in trouble. I made the offer to flow your work, you pay the shipping. Again congrats on picking up power, I expressed my findings was all. I didn't just pick up a grinder and say oooooooooo I made 13 rwhp, I studied and studied to make things better.

I know things that can help you, if you choose, we can help one another. I have given you tons of advice, do not turn this into a dog fest......