dfinke23

Is anyone getting a substantial increase in flow by porting the LS7 heads? I know you can make good power with milling, but I was told the OEM LS7 heads flowed really well and any increase would be minimal, and would not justify the $$$.

bandit0220

copied from the other thread where you asked the same ?

The best person to ask that ? is Jason they are by far the best at knowing the LS7 in and out not to mention Chapman racing here in Utah who were the developers of the LS7 heads, and last but not least lil ole me I did an independent test as to rwhp increase by just upping the compression. I gained just under 30 rwhp from upping my CR without tuning after tuning it was a gain of 33 rwhp. The average gain from porting is suppose to be 35 rwhp but I have also found that almost every company that ports these heads also mills them as well and thats where the horsepower gain is coming from. Jason talked with me in length about this as did Mike Chapman and said the gains from just porting alone is very little the heads are highly efficent from the factory even with the lower flowing exhaust side. To me proof is in the pudding and I like to see step by step gains. I plan on removing my heads and having them ported and will report any gains. But I dont see getting more than a few more rwhp over my milled numbers. Remember its all a buisness believe half of what ya see and none of what ya hear, prove it to yourself. Why spend a grand for ported heads when you can spend a little over a 100 and get them milled and get almost the exact same gain that they do. Cause if milling them just a touch and porting returned gains of 60+ rwhp then hell places like Katech would be all over that and would have it as an option.


Now I know that every vendor that offers porting is going to come out of the woodwork but I have asked every one that I haved talked to and they all said they mill the heads. I challenge you to do just the porting and slap the heads back on and show me the same 35 rwhp gain that you all claim is from the porting. If anyone has the ***** for it I have a dyno here and my car has been a rolling test bed for almost every cam out there and I have always given unbiased opinions to the cams I have used. I have already had the heads milled an gained 33 rwhp after tuning them back in if you are so confident that your claims are accurate I will remove my heads pay to have them shipped to you and back. I will show a before and after dyno, if the results are as you say, and I gain even 25 more rwhp over my previous numbers after retuning not only will I pay for the dyno time, post up and praise your company to the sky, I will also say I was wrong AND I will pay double the porting cost to you. Any takers????????

dfinke23

I didn't want to hijack the cam thread.

I hope I'm not the first to say it , but thanks. I appreciate the way you test your car so that we can see te actual gains of each mod, it's priceless.

When are you planning on having your heads ported?

Katech_Zach

We saw minimal gains porting LS7 heads - about 5hp. Its hard to improve on a head that's already CNC ported from the factory. On the flow bench, gains found on the top end were often lost on the bottom end. Also, you're limited by the intake manifold.

Randy@RaginRacin

We have been using MTI Heads. Let me just say I have testedd several sets of cylinder heads and most of them out there gain 5-11hp. MTI heads were the first we used to see 25+. On 3 different motors now we have seen +28,+31, +27. All 3 of the sets were milled. We test everything before releasing it. Some of the crap out there is unbelievable. I would talk to as many shops as possible before buying a set of heads.

aTX427

More of a result from compression than porting??

dfinke23

I would like to see someone test a set of LS7 milled heads prior to porting, then after porting. Maybe someone should take bandit up on his offer. Besides him paying double, I would be willing to commit to a set if they make 20 + RWHP with porting alone, tested as described above.

bandit0220

Ive thrown it out there but heres where you will see the truth behind the smoke and mirrors. I told ya you wouldnt see many step up to "show" that porting does what they claim it will do porting is not what gains the power its the milling that gets the gain.

So there ya have it vendors you have me willing to be the guinea pig. I milled and gained 33rwhp, with a set of stock LS7 heads. I have offered to remove, send, and dyno a set of ported heads by any vendor who has the faith in their product. If and I mean IF I gain even 25 rwhp over what I made with just the milling Im willing too pay you double and you have a guy willing to buy a set. Not only that but Im willing to post up the unbiased dyno results both good an bad. I will be doing the tests after the tunes are perfect. In an economy such as this you would think this would be a sweet deal, that is unless the smoke and mirrors are just that they seem. Nothing but BS

BADZ

So the secrete is in the milling?

J HEBERT

I am still waiting for a vendor to take the "head job" challenge Don't hold your breath, we will be modding C7s before that happens

kumar75150

yeah, i have heard all kinds of mixed reviews even from vendors about heads. I hear some cars picked up 35rwhp but then the same brand heads only picked up 10rwhp on the next car.

I want to do heads but I'm not about to spend the money unless I know what to expect.

bandit0220

I know I am just putting it out there and when noone takes the challenge all it does is lose them money and show that they too arent honest on what makes power and what doesnt

Yes the secret is in the milling maybe a couple horses gain from porting, 3-5 rwhp but too me thats not worth 900.00 more than just milling the heads. Not to mention its easy to screw up a set of heads and make them flow worse than before as well. Remember who gives a hairy rats butt if the head will flow 400 cfm at .700 lift if the cam your running is only going to .600 to .650??? Wheres the gain??? Then theres our intakes and RPMs is the best I have tested and did make dam near exactly what he said it would. But it still cant flow near what a stock head can flow let alone a ported one again you cant use a ported head till you get past this little problem first

2002rich

Thank you Bandit0202 for sharing. Very interesting and informative!
Are you planning on porting your heads if no vendor takes you up on your challenge? I am really curious to see the results of porting after milling

Katech_Zach

That is laughable.

kumar75150

so 31 is possible but 35 is not?

or are you calling him a liar?

Katech_Zach

This reminds me of a story. Years and years ago Katech was building NASCAR engines. They all made about 585hp on our dyno yet the shops down south were claiming 600hp. Fritz (founder of Katech) put a bounty on a 600hp engine. $1000 (a decent amount of money at the time) + free dyno to the first person who brought in a 600hp engine. He even took an ad out in a magazine.

Do you know how many people showed up with 600hp engines?






Zero.

Randy@RaginRacin

Couldn't say for sure as I have not tested the MTI Heads unported. MTI Says 20 hp without milling and 30 with.

Here is the article on heads. Take some time and check it out.
http://www.gofastnews.com/board/tech...oved-upon.html

dfinke23

I don't think 31 is possible with porting alone, let alone 35. I think what is being made clear is the vast majority (approx. 85%) of hp made by ported/milled heads, comes from the milling, which is about 10-15% of the total cost of the mod.

kumar75150

well in that case, maybe i'll just get a valve job and mill my heads instead.

should be able to get away with 12:1 on a big cammed car right? (93 octane)

Randy@RaginRacin

I don't believe I called anyone a liar. I just stated the results we have seen. Just like I haven't seen 600 RWHP yet with cam and heads. I have seen a vender put together a car and told the customer it did 580 only to go put down 530 on 3 other dynoes. That was a Head/Cam car as well