home porting

[usetaboost]

what's everyones opinion on this? Some people say a little polishing goes a long way and others say to not touch things and leave it to the pros with a flow bench. I have never done it before but have been thinking of just doing some polishing of the ports and valve bowls just to smooth things over. WHat about the intake is it worth the time messing with it? I already had planned on doing the exhaust elbow. What about the exhaust manifolds? Has anybody done anything with these with success/failures? WHat can be smoothed over by a novice and what should be left to a professional? Are there any threads for porting and polishing buick turbo parts?

 

[84BuickGNYorkPA]

Try this link

http://www.sa-motorsports.com/diyport.shtm

Chuck

 

[knperformance]

what's everyones opinion on this? Some people say a little polishing goes a long way and others say to not touch things and leave it to the pros with a flow bench. I have never done it before but have been thinking of just doing some polishing of the ports and valve bowls just to smooth things over. WHat about the intake is it worth the time messing with it? I already had planned on doing the exhaust elbow. What about the exhaust manifolds? Has anybody done anything with these with success/failures? WHat can be smoothed over by a novice and what should be left to a professional? Are there any threads for porting and polishing buick turbo parts?

It is best left to someone who knows what they are doing you can ruin a pair of heads pretty easy if you cut to far into a water jackets.Lots of people just go in there and start hoggin and kill the velocity and make it worst then stock.You got to know where to grind and how much, if you just want to try it ok to smooth out any casting bumps or flashings and come back with eighty grit paper to smooth out the carbide cut marks, i port alot of buick and other types of performance heads if you have any questions.

 

[bison]

A quick bowl blend and a good valve job will net you a great increase in flow with little time and money spent. When you remove the valves it will be clearly obvious where to remove material. I wouldnt do to much with the ports other than to make sure they line up with the intake and exhaust manifolds unless you are experienced at head porting. The exhaust manifolds should be dowel pinned in place after alignment is achieved.

 

[VadersV6]

Seriously, if you have never ported heads yourself, do not touch them! Ive seen what first timers do to good heads. You need to go through at least 10 sets of heads before you're doing a quality job. Opening up ports can kill power if you remove 1/8" in the wrong place. There is so much more to porting than gasket matching, "bowl" blending, or hogging the ports out. I went from 216cfm at .500 lift to 243 at .300", 295cfm at .400", and 297 at .500" on my cobra heads I ported. people think you would have to hog the hell out of them to get these numbers. I didnt even remove 1/8" from the cross section. Just like real estate, its all about location location location! Ive had alot of porting jobs under my belt, but having alot of experience is useless compared to knowing what youre doing and why. Go buy a condensed book on fluid dynamics...they make some that are directed towards idiots like me, that even I can understand. Go through that book and what you'll learn will be so much more powerful than a "how to port" manual.

 

[Ormand]

There are pictures at GnTType.org. Along with some flow numbers. When they had everything done, they back cut the intakes, and got a big improvement. Would have been good to see it done the other way around, to see if back cutting the intakes would have given most of the improvement, without all the porting. Also, might look around on the internet. Some people in the cycle world have proved that flow bench numbers don't correspond to dyno numbers, or wins at the track. (Some intake manifold manufacturers have figured that out too.) Bigger ain't always better.

 

[usetaboost]

Sounds like I should leave the heads and intake alone

is there anything I should smooth out then? I read something on another thread a while back a guy did something with his intercooler and the throttle body and gained 1 lbs of boost for each one on pump gas. This is stuff I think I could do myself. Just got to find out what to do exactly. ANy suggestions? PICS GO GREAT WITH INSTRUCTIONS!

 

[twin 93 svt]

buy an extra set of heads from the junk yard, and go to it. you would have no down time, and worst case scenario you are out $40.00 and your time.

 

[Ormand]

is there anything I should smooth out then

Anything in the flow path will help. Much of it won't help much, but all together, it adds up. Look at the inside of the opening at the throttle body, and at the inside of the opening going into the intercooler. There is a lot you can do to the turbo, too. And there are pics somewhere, probably at GNTType.org. I know there are pics on how to do the exhaust elbow to the turbo, and the inlet., tot.

 

[VadersV6]

I gained 1psi by sawing off the rolled lips from the ends of the up-pipe, Gained another 1psi from my 3.5" intake tube. Gained 2 from my Dutt neck. I also bellmouthed the dutt neck inlet cause even that has a really sharp edge which is disastrous for flow. I radiused the TB inlet. Dont know if that gained me anything. Probably not. These are all things to reduce the pressure drop after the turbo. People say the stock IC has a 5-6psi pressure drop, but based on what I saw, it doesnt all lie in the IC.

 

[bison]

I gained 1psi by sawing off the rolled lips from the ends of the up-pipe, Gained another 1psi from my 3.5" intake tube. Gained 2 from my Dutt neck. I also bellmouthed the dutt neck inlet cause even that has a really sharp edge which is disastrous for flow. I radiused the TB inlet. Dont know if that gained me anything. Probably not. These are all things to reduce the pressure drop after the turbo. People say the stock IC has a 5-6psi pressure drop, but based on what I saw, it doesnt all lie in the IC.

I agree, its not all the intercooler. I noticed the same increases years ago when i was in high school and had no money. So i did those mods myself. The factory plenum inlet is horrible if left stock also. Its a considerably smaller and causes flow restriction if not opened up. The stock throttle plate can be knife edged on the top also to pick up a little more flow and the throttle shaft thinned out. Be sure to stake and loc-tite the screws if you do this mod. I went 11.87 with the stock turbo and a dutt neck intercooler back then. I feel those mods were worth 2-3 tenths and 3mph. The car probably wouldnt have dipped into the 11's without them. Its also worth grinding out the inlet side of the stock turbo to smooth out the flow. I may try and build a stock turbo engine in the future. I know sub 11.50's at full weight is achievable. Ed Brewer already did it.

 

[usetaboost]

First off, I have an extra set of heads they are off the 82 motor. THese have the same size ports right? As far as grinding away the rough edges can I just use a regular dremel kit like at wally-world or do I have to spend the 50 bucks and get a porting kit? I probably won't mess with the heads, for 600 bucks I can get a "performance street" job done or I can go "race" for 1000 this guy has a flow bench and lives right up the street. Should I put new valves and guides in now or wait till the heads get done? stock stainless manleys or "swirlies"?

 

[VadersV6]

First off, I have an extra set of heads they are off the 82 motor. THese have the same size ports right? As far as grinding away the rough edges can I just use a regular dremel kit like at wally-world or do I have to spend the 50 bucks and get a porting kit? I probably won't mess with the heads, for 600 bucks I can get a "performance street" job done or I can go "race" for 1000 this guy has a flow bench and lives right up the street. Should I put new valves and guides in now or wait till the heads get done? stock stainless manleys or "swirlies"?

Just buy a set of champions. Because they're CNC ported, they are totally consistent in flow and velocity from runner to runner to runner, and you get alot for your money. Dont do them yourself. You can maybe do the intake yourself, but measure and mark 3 times, cut once. Take your time, and take your time, and take your time.

 

[usetaboost]

I think I'll just get a power plate and call it good and concentrate on the tb, ic, and exhaust elbow. thanks guys!