Speed Demon

iTrader: (14)

Well I finally got the car dynoed with the home ported heads.

For $1500 more I could have sent them to a pro and probably made 20-25 more hp.? Maybe more hp?

The results are nothing to brag about, but it was a learning experience.

The car made 386 rwhp and 375 rwtq. SAE correct supposedly. A/F was about 13.1 then dropped to about 12.7-12.5 @6300 rpm.
Before heads 365 rwhp.
So a 21 rwhp gain.
I can post sheets Monday if someone will tell me how.

The mods are below in sig plus heads. I am now running stock MAF (no more GMS), hypertech pwr tuning w/ 6600 rpm rev limit, and 17 inch wheels, w/ a 6 spd.

6.0 head specs.
Ferrea 6000 series 2.02/1.55 valves, installed as received (no back cut)
Standard three angle valve job, by local machine shop.
Heads milled 0.030, chambers cc'd to 63.5 cc.
Combustion chambers polished.
Intake port 214 cc, up from stock of 210 cc.
I only removed 4 cc of material, doesn't sound like much.

Set up with MMS springs, ti retainers, 1.750 in. installed height, 150 lb seat pressure, 360lb at full lift.

I am not sure if the dyno operators knew what he was doing. My CF was 1.0 and it was 82 degrees with 70% humidity. When I asked him about correction factors he said the numbers would be low since it was hot out. I asked him wouldn't the CF correct for that? He just looked baffled.

How much would I gain if I had one of the top LS1 shops set up the valve seat angles and back cut the valves?

I am considering later on, sending these heads to a pro and see what they can work out of them.

If anyone can tell me how to find more power out of this set up let me know. I should have some autotap data from the dyno soon (friend saved it for me).

A 6spd 99' SS ran right after me and put out 367 rwhp (SAE) with the following mods,
SLP LT's w/ cats
Cut out
TR224 .561 114LSA cam
LS6 intake
lid
ported mass air

We thought he would have made more, but I did race him heads up at the track and I trapped 3-4 mph higher.

First time ever at the strip on street tires I ran 12.66 at 115 mph.

VINCE

iTrader: (1)

That is still a good job for someone home porting I think.

Straight Line Performance

I don't know, 21 hp sounds good to me for home porting. I think these shops are charging waayyy too much for head porting. Did you take any pics? I'm wanting to do my heads myself.

Later,
Albert

Speed Demon

iTrader: (14)

I tried to get some pics, but they didn't come out so good. I wish I had better pics and flow numbers but I was ready to get it back together.

I used Jantzer98z's info to do most the work and a few other tips and pics I got from others.

Try a search using his username minus the "'s" of course on LS1.com. He has lots of pictures and info.

Thanks for the feedback and let me know if you decide to do your own. I'll give you all the tips I can, but I am still a novice.

I probably spent 40-50 hours on the heads, but also I realized some ways to save time, with better technique and tools.

Crazyquik

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Speed Demon:
<strong>
I am not sure if the dyno operators knew what he was doing. My CF was 1.0 and it was 82 degrees with 70% humidity. When I asked him about correction factors he said the numbers would be low since it was hot out. I asked him wouldn't the CF correct for that? He just looked baffled.

</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Did you go to the guy down in Belmont, or to True Blue or Turbo Tune or where?

J.

SNW Vette

Hi,
Do you know what the barometer was reading during your runs? It would need to be something like 30.154 “Hg (really high) to get an SAE CF of 1.00 out of an 82 F by 70% day.
I think you did really well.
Steve

zZAndrusZz

When people in norf carolina do stuff like this they do it right. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Speed Demon

iTrader: (14)

SNW Vette,
Here are the conditions they printed off for me.
They didn't print humidity, but the local news said %70.

The shop did give 82.0 F and 29.8-0.37 Hg CF=1.00

right off the sheet.

Andrus,
The shop just got their dyno and I don't think they know much about it or domestic cars.

They tried to tell me a 355 ci SC'd car would make more rwhp than equally boosted 396 ci SC'd car. I gave up arguing with them.

Some other things happened too that worried me a little about them.

zZAndrusZz

Where was this shop?? Do they normally tune ricers? Sounds like they believe those euro style clear tailights will add horsepower too. I want to go to this shop, I'd enjoy making them look foolish. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Andy

SNW Vette

Hi,
For 82F, Baro 29.8 & P water vapor 0.37 the CF is 0.998 (~1.0), like they said. This corresponds to a relative humidity of ~33%. If the RH was more like 70% the CF would be 1.014.
Good luck,
Steve

CHRISPY

I am a little confused, you have 63cc combustion chambers with a stock bottom end?
Doesn't that come out to fairly low compression?
Just curious as to why you didnt go with a CC of around 57 or so?
Cheers,
Chris

Speed Demon

iTrader: (14)

Chris,
Stock 5.7L heads cc to 67 for 10:1 C/R.
The 6.0L heads stock are approx 72cc so I am told.

With 63cc chambers my C/R should be about 10.6:1.
I would have liked to have at least 11:1 CR.

I thought about milling them more but was worried about piston to valve clearance if I went with a bigger cam later.

I believe 60cc chambers would be around 11:1.