Porting questions

[1984 t-type]

What type of performance gains can I expect from porting the stock factory heads and intake ? The only internal mods I have done is the cam on my signature, motor is a fresh rebuild so the only other mods i plan on adding will be external bolt ons. My goal is a street car in full trim that runs low 11's with ease. Also is that possible with my 42# injectors ? There new and I would hate to have and buy new ones.

 

[Nasty]

Performance gains from ported heads will vary greatly. It would depend on the amount/quality of the port job, and your supporting mods, such as turbo, downpipe, etc. From what you have now your gain would not be much. If the heads are off, a good 3 angle valve job and clean up the bowls would help. Stock heads are good to the 11's, it would be easier if they were ported but not required. Just the valve job and bowl clean up would be more than enough for what you want. The mods are more important at that level.

If you search enough, you will see its best to start with a good fueling system. Walbro 340 hot wired, adj regulator, your injectors may get you there with alky. 3" downpipe and 2.5" exhaust. Bigger turbo, assuming your torq converter is stock you will need a turbo that is low stall friendly. A TA49 would work, or a something a little bigger in a BB version. Alky Injection (Razors kit ). Of course tuning tools...fuel pressure gauge, boost gauge, Scan Master, (WB O2& Power Logger is a plus).

I would not put to much effort into the heads at that level. The money spent else where would be a better investment. Suspension, sticky tires, etc are more important in getting the power to the ground that the bolt ons are going to produce.

 

[lnkncontiverto]

This should give you a good idea of what to expect from a well done home port:

http://www.turbobuick.com/forums/engine-tech/258301-follow-my-port-polish-project.html

 

[turbofabricator]

A set of well ported heads will gain you 50+ hp depending on many of factors. If you install a nice set of heads with a stock turbo, expect approx. 45-50hp. Step up to a bigger turbo, the power goes up. If you plan on keeping the car at a 10.5 or slower, stay with ported irons, especially if street driven. Go TA aluminum if you plan on going faster.
If you plan on home porting, be sure to read, read, and read on the basics of what you are trying to accomplish. Just taking a grinder to the ports will sometimes net you little. Go with bigger valves at the same time. Check my posts as I have recently written on where to grind. But reading it and actually doing the same thing is pretty tough. Unless you plan doing a few sets of heads over the next year, I would suggest buying a nice set of ported heads. By the time you buy all the needed tools and safety equipment you will probably be ahead buying store bought heads. It also takes ALOT of time to do a set of heads correctly.
But if you want to give it a try, go for it. The only way to learn is to do it.

 

[charlief1]

A set of well ported heads will gain you 50+ hp depending on many of factors. If you install a nice set of heads with a stock turbo, expect approx. 45-50hp. Step up to a bigger turbo, the power goes up. If you plan on keeping the car at a 10.5 or slower, stay with ported irons, especially if street driven. Go TA aluminum if you plan on going faster.
If you plan on home porting, be sure to read, read, and read on the basics of what you are trying to accomplish. Just taking a grinder to the ports will sometimes net you little. Go with bigger valves at the same time. Check my posts as I have recently written on where to grind. But reading it and actually doing the same thing is pretty tough. Unless you plan doing a few sets of heads over the next year, I would suggest buying a nice set of ported heads. By the time you buy all the needed tools and safety equipment you will probably be ahead buying store bought heads. It also takes ALOT of time to do a set of heads correctly.
But if you want to give it a try, go for it. The only way to learn is to do it.

Some of us have paid attention to the posts on porting and have some experience doing it. Here's an example of what you can do if you take your time. Thanks again Ken.:biggrin: