99Hawk262

iTrader: (19)

I have a couple questions concerning a street port for stock LS1 heads. I have a reputable machine shop that said they'd do a street port for about 300 bucks. Just match the heads to the gasket and clean out the bowls. Has anyone done this? Is it worth it. The engine guy said about 40-50 horse. For 300 bucks, that's pretty cheap. But is it real? What kind of power would you expect from this? Also, getting ready to swap a cam in a buddies 99 Z28. I have the guide from LS1how-to.com. Did I read it correctly when it says to just pull out the old cam and put in the new one? What about lining it up correctly....or will it only fit in one way? Just want to make sure we do this right the first time. Any input is greatly appreciated. Thanks.

Brian Tooley Racing

iTrader: (13)

I responded with a "ditto" to Tony Mamo's post, but then he pulled it off.

Not going to happen, 20 horse maybe.

99Hawk262

iTrader: (19)

So not really worth the time to pull the heads or the money. Kinda what I thought.

Tony Mamo @ AFR

iTrader: (13)

I thought I would let someone else give him the sobering news....LOL

BigSteele

iTrader: (17)

what about sanding and polishing the intake and exhaust ports yourself (home porting the heads), if the cc volume is a little different would this be bad? I think the bowl would be an issue, but not as much for the intake runners, so what about just leaving the bowl and doing the intake/exhaust
If you could sand things down and polish it, wouldnt it be better overall even if its not as percise as a professional port/polish/matching

Tony Mamo @ AFR

iTrader: (13)

"Smoothing" port walls does very little (if any) help in providing extra airflow. It's purely cosmetic for the most part....try it on a flowbench and you will be surprised at the outcome...little or no change. Also, if your "heavyhanded" on the short side or any other sensitive area, you take the chance of losing flow if by accident you alter the correct shape, create a flatspot, lip, etc....

I just had a set of 205's here on our flow equipment that were claimed to have been improved by a local shop....This guy literally just sandrolled all the ports, barely removing all the CNC marks, charged the customer $1000 for his trouble, and gave him back a head that flows identical to a 205 out of the box....The good news is at least he didnt charge him a grand and give him a LOWER flowing piece than what he brought in...that would have really sucked.

Buyer beware folks....

xfactor_pitbulls

iTrader: (16)

I think it is safe to say for the do it yourselfer. The best results, without risk of messing something up are to: 1. take out the rocker "hump". 2. cut the vakve guides down like the pictures you see online 3. cut the swirl ramp down to the circle impression just south of the valve guide and put a good radius on the ramp and the wall. Those steps will yield good results if done well. But like anything you need to practice before you go to town. I think scrap heads are a must. The proper equipment is also a must, 6" shank is the only way to live, along with a cheap 1/4" ELECTRIC grinder. The exhaust side IMO is more tricky than the intake side, even though from first glance it looks easier. The biggest gains someone will get without pro training is just to cut and contour the valve guides and take the walls out to around 1.58" or so, telescoping gauges and a mic are very helpful here. Hope this helps on a pretty basic level.

Brandon

ddnspider

iTrader: (26)

what about companies like MTI who CNC their heads then hand finish them,i know they're expensive, but other companies are starting to follow suit,does the hand finishing help?

xfactor_pitbulls

iTrader: (16)

MTI doesnt CNC, they are soley hand worked. If a company has a state of the art CNC machine they can basically duplicate someones design, whatever shape it may be, perfectly. The hand finishing aspect just helps to refine flow somwhat and mainly give less of a surface for deposits to form. This is all presuming that the CNC program is one of the better ones that yields good flow. The more I do this stuff the more I realize that one you start on a port shape and are most of the way there you cant turn back. It holds true for finishing someone elses work.

Brandon

ddnspider

iTrader: (26)

gotcha!

ls1_cam2

iTrader: (1)

anybody know if there is a site where it shows how to port you own heads?