Question about Porting and Performance, and head intake advice
#1
Intermediate
Thread Starter
Question about Porting and Performance, and head intake advice
I have a stock 85 Vette Auto. I may need to do a intake gasket i beleive since it looks like it may be damp though the car runs fine. I want to keep my car stock looking and when i am done modding i would like a Mid to low 13's car. I would like 12's but ive researched that its gonna cost more than im looking to spend on the budget im working with. How much power might i achieve by having a machine shop port out intake manifold, runners and heads? i have searched and haven't heard of anyone porting the iron heads? I have seen these on C-list http://detroit.craigslist.org/wyn/pts/3456176868.html any opinions, as i dont know what i need and if they are direct bolt ons. and i saw this http://detroit.craigslist.org/mcb/pts/3464232060.html same thing, is it what im looking for or a direct bolt on etc? hoping someone can help shed some light as i learn these cars. There a different beast then the 2.2 Turbo II motor im used to working with.
Rich
Rich
#2
Team Owner
Member Since: Oct 2004
Location: altered state
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St. Jude Donor '05
Check your pms.
13s are easy
13s are easy
#3
Race Director
Being in Michigan, I gotta think you've got some decent access to head rebuilders/porters. Have you talked to any local people?
FWIW, I bet there's not many people messing with iron heads anymore. Too many alum heads running around. Plus, you can bump compression on alum "easier". Compression is one of those desirable things too.
More compression makes for a more efficient motor. As such, you get more MPG's with the result. If savvy, it's possible to improve both power and economy.
Consider sellling/trading your iron heads from some used alum...especially if you find a good local shop to do the porting. For what you're talking about, porting costs should be too high...plus to could bump the size of the valves.
You might even get lucky and find some already ported alum heads for sale hear/there. Just make sure someone knowledgeable checks them out first hand. No advantage to buy something that been ported badly or ready to pop thru a wall somewhere.
BTW...Just checked out your links. Both options look promising. See if you can find a local CF'er willing to check those out -- if you need a 2nd opinion.
FWIW, I bet there's not many people messing with iron heads anymore. Too many alum heads running around. Plus, you can bump compression on alum "easier". Compression is one of those desirable things too.
More compression makes for a more efficient motor. As such, you get more MPG's with the result. If savvy, it's possible to improve both power and economy.
Consider sellling/trading your iron heads from some used alum...especially if you find a good local shop to do the porting. For what you're talking about, porting costs should be too high...plus to could bump the size of the valves.
You might even get lucky and find some already ported alum heads for sale hear/there. Just make sure someone knowledgeable checks them out first hand. No advantage to buy something that been ported badly or ready to pop thru a wall somewhere.
BTW...Just checked out your links. Both options look promising. See if you can find a local CF'er willing to check those out -- if you need a 2nd opinion.
Last edited by GREGGPENN; 12-16-2012 at 12:50 AM.
#4
You can do 13s with mild work...12s with more extensive intake work and some exhaust upgrades to get it out as well as it gets in...
I'm not at all sure about the iron head, but I know the alum heads can be matched up from TB to intake valve for significant gains. Inside the stock passages is just plain ugly. It can be reshaped, opened and matched to greatly enhance the airstream volume AND velocity. There are those that say the GM heads aren't worth the work. I disagree. They CAN be made to flow well but it does take some effort. Some folks just don;t mind buying what they want. I'm too cheap...I'll admit it cost damn near as much to make the stock head work well as a set of AFR heads or other name brand but having the stock appearence is worth something...
Thats the one real big issue that cannot be ignored...the runners. Heads are one thing. Lots you can do with the stock head. Runners. no. The tubing is wayyyyy too thin to open up, and they are very unique so the stock vs aftermarket is pretty obvious. Its acceptable though...everyone pretty well understands that the stock runners got dinged and dented and thrown away.
Get some SLPs that are semi-siamesed and cast and have LOTS of meat that can be ground out to match the baseplate and you're in bidness !
I've got a whole intake assy on my bench thats getting ported, matched and polished and will be matched to a set of heads that have been "altered" dramatically inside. The only clue will be the runners and the polished metal.
I'm not at all sure about the iron head, but I know the alum heads can be matched up from TB to intake valve for significant gains. Inside the stock passages is just plain ugly. It can be reshaped, opened and matched to greatly enhance the airstream volume AND velocity. There are those that say the GM heads aren't worth the work. I disagree. They CAN be made to flow well but it does take some effort. Some folks just don;t mind buying what they want. I'm too cheap...I'll admit it cost damn near as much to make the stock head work well as a set of AFR heads or other name brand but having the stock appearence is worth something...
Thats the one real big issue that cannot be ignored...the runners. Heads are one thing. Lots you can do with the stock head. Runners. no. The tubing is wayyyyy too thin to open up, and they are very unique so the stock vs aftermarket is pretty obvious. Its acceptable though...everyone pretty well understands that the stock runners got dinged and dented and thrown away.
Get some SLPs that are semi-siamesed and cast and have LOTS of meat that can be ground out to match the baseplate and you're in bidness !
I've got a whole intake assy on my bench thats getting ported, matched and polished and will be matched to a set of heads that have been "altered" dramatically inside. The only clue will be the runners and the polished metal.
#5
Intermediate
Thread Starter
any thoughts on the custom intake i linked and the heads? ty so far for all the advice. the heads are 380 a set. dont know if its what im looking for. intake sounds nice but the setup is different that what i have. no long runners? i wanna keep my torque lvl high and someone told me that i would loose torque with a shorter runners? ty
Rich
Rich
#7
Intl Council of Corvettes
I swapped my iron heads and went with a set of Dart Pro 1 200 series aluminum heads. I will tell you they are great heads already out of the box and will let that vette breath really good. I paid $1275 for them DAR.11311112P.
#9
Le Mans Master
For the price the #113 heads would be a great deal. These are much better than the stock iron 85 heads. Consider going with the heads and perhaps porting the intake and the plenum yourself. You can buy electric die grinders for a reasonable price and these two areas are something that you really can't screw up .....as long as you don't grind thru to the other side and make what is known as a HOLE.
On the intake, basically match the gasket and smooth out any casting imperfections. For the plenum there are many pictures on the Forum showing the before and after.
You will get a very good gain on making the car go faster by replacing the front "Y" with one that is 2-1/2" diameter tube, replace the cat with a straight thru pipe. And if you want to keep the stock look mufflers, then get a set were both exit pipes work. Also add March under drive pulleys.
On the intake, basically match the gasket and smooth out any casting imperfections. For the plenum there are many pictures on the Forum showing the before and after.
You will get a very good gain on making the car go faster by replacing the front "Y" with one that is 2-1/2" diameter tube, replace the cat with a straight thru pipe. And if you want to keep the stock look mufflers, then get a set were both exit pipes work. Also add March under drive pulleys.
#10
as far as the grinding and cutting...you can buy cutting bits at Home Depot for electric grinders & dremmels, or to fit drills that cut aluminum like butter! I've got some that will flat eat the aluminum up. I use those to cut the openings of ports where they have been marked with Felt-tip pen, then go back with flap wheels or some similar sanding tool to level it out and knock down the rough. Like John Marker said, you really can;t screw up in the plenum or baseplate...bigger is better there and you can shape the passages, match the ports to gasket, and knock down all kinds of casting junk. I have piles of ground up aluminum on my table whenever I do an intake for someone.
Like he said, just don;t make a hole and you;re ok.
Like he said, just don;t make a hole and you;re ok.
#11
Melting Slicks
A local guy i've used before does CNC work right out of his garage ... Really nice work and great price . The last set he did for me was a AFR 210 head that i got as cast from AFR and had him port it , that head went low 10s in my car .
jerry @ BHP
734-455-1905
Tell Him "Cheap nick " with the AFR heads sent ya .. LOL I was in high school when i met him and a was trying to get the best price from him , so he calls me cheap Nick .. LOL
jerry @ BHP
734-455-1905
Tell Him "Cheap nick " with the AFR heads sent ya .. LOL I was in high school when i met him and a was trying to get the best price from him , so he calls me cheap Nick .. LOL