C4VetteLS1

A local guy is having huge problems with his newly installed heads/cam/bolt on transam.

The car made 330 rwhp with some Cnc ported heads, stock cam, headers/boltons, ls1 intake.

Swapped to a TR224 cam, some privately stage 2 ported heads (got them off ebay, a guy named "Brian Neeland" , he included flow sheets showing 302 cfm/ 220), and ls6 intake, underdrive pulley

But after this swap and tons of issues to work out. We got the car on the dyno today to do some ls1edit tuning.

We expected 390-400 rwhp with no tuning. The car put down 333rwhp!!!! its horrible. the car runs fine and good and just makes no horsepower.

1) i know the cams in properly, not a question
2) all injectors/plugs etc are working fine, the car seems mechanically sound.


The question we have is that every set of heads ive seen have the little bump in the intake runner where it gets to the valve and goes around it, it was smooth on this set of heads, it just seemed odd, but the heads look very good and they didnt seem hogged out. we had just never heard of the guy who ported them. any ideas?

ArcticFormula

Not sure, but would like to see a digital picture of the heads if you have one.
Regards,

C4VetteLS1

heads are on the car, so wed have to yank intake.

but when you look in the intake port you can see a noticeable bump where the valve goes through. it was the first pair ive seen without it, logic would tell me to smooth it and remove it, but this is the first ive seen without it

TA2SLOW346

iTrader: (3)

https://ls1tech.com/ubb/cgi-bin/ulti...;f=41;t=007299

LS1derfull

C4 Vette, i just reviewed that Archive post link and it adresses swirl ramp pretty acurately. That aspect of port work would not cause poor performance on dyno, it may cause higher timing requirements than leaving ramp intact, but thats on paper and i havent proven this. I would look at tuning for answers to low dyno power.

LS1derfull

Formula 1, not to come to this guys rescue but his .550" flow was only off by 4cfm from 2 diff. benches. If you are not running .600" lift than that figure is a moot point. If you bolt intake on ports you will only see 270 to 280 cfm max flow. Getting really high 300+ cfm ports may not give the extra power that you would expect. Just dont want people to chase the highest no manifold flow numbers, there is more to it than that.

Fly By

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by C4VetteLS1:
(got them off ebay, a guy named "Brian Neeland" , he included flow sheets showing 302 cfm/ 220</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thats your problem right there <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

<small>[ February 21, 2003, 08:46 PM: Message edited by: Fly By ]</small>

JPR

This is just an idea, but bolt your old stock heads back on with the new valve springs and re-dyno to elliminate/isolate any other possible problems. Stock heads TR 224 M6 should lay down 365-376 RWH. I'ts just a suggestion because 278ish @.550 is a good number for 390-400 RWH unless they have really been hogged out for no reason.

Joe

LG Motorsports

I would re check your plugs, pull them out and check the gap, and look for "cracks" in the porcelin. Also check the plug wires when you take them off. make sure that they were all the way on and verify that they are not damaged.

I know it sounds simple, but unless the cam is in wrong, or a push rod is not in, then it could be very simple. (plug, wire, coil, injector, pushrod, broken injector wire, etc.)

LG

red90cobra

iTrader: (36)

I figured when u take the swirl bump out its a race head. U loose cfm at lower lift and gain big at the bigger lift. That's what I thought. Am I not rigtht? Does anyone know any truth to this. I'm thinking bout taking that bump out to increase flow numbers.

largecubes

My name is Bryan Neelen and I ported the heads in this thread. Here is some information about me. I have been porting heads and building LS1 engines since they came out in 1998. I also build circle track and drag motors. Over this time, I have ported many sets of heads and have spent countless hours of R&D on LS1/LS6 cylinder heads. From this work, I have put together an efficient port and valve job combination. This is my full-time job.

It is not uncommon for the swirl bump to be removed. The swirl bump is located in a high velocity area in the port. Removing the bump essentially raises the port roof allowing more port volume for air to flow in this crucial area.. The purpose of the bump is to promote swirl and tumble. This is beneficial to gas mileage, idle quality, and low rpm efficiency. However, when you are looking to improve performance at the mid to high rpm range you need to focus on how the air and fuel are traveling through the port at considerably higher rates. The swirl bump becomes a restriction and impedes the course of travel through the venturi and over the valve job.

In response to flow numbers, a point was made that every flow bench is different. This is very true. The flow bench is only a tool. I use this as a tool by taking a baseline number and compare it with the final results. If I gain 50 cfm from a set of heads, it doesn’t matter if the port flowed 200cfm and went to 250 cfm or if the port went from 250 cfm and ended up at 300cfm. The only things these numbers tell me is that I gained 50 cfm. It is all relative to your baseline numbers. Don’t get me wrong, midlift numbers are also extremely important, if not more important than the peak number.
To address the cfm differential discussed in this thread, many variables can come into play: intake orifice, bore size of flow fixture, cylinder head location on bore, variations in valve lift when reading is taken, calibration of flow bench. My test was done on a superflow SF1020 @ 28”H2O, on a 3.900 bore with doweled flow fixture to locate the head, and a radiused intake orifice made of Plexiglas. No exhaust extensions were used.

I appreciate those of you that read my response. Sorry its so long. I am always honest with my customers and in no way try to mislead anyone about my product. This is my first instance of some being down on HP. I fully stand behind my product, and I hope to try to help you figure out where the bug is in your set up. Feel free to give me a call. 281-890-8498

Thank you,
Bryan Neelen

Here is a link to the ebay auction of one of the sets I sold. Please review the pictures.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=1871704331

Jason99T/A

iTrader: (21)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Formula 1:
<strong>He claimed 289@.550 $ 296@.600. which are probably average compaired to todays standards. I had them flowed just to ease my mind and sure enough he lied about his numbers. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You just said every flow bench is different, so how can you say he lied about the numbers? The only way to compare flow numbers is on the same bench, same day, with the same operator. Period!! The things mentioned above (bore size, type of entry used, model of flowbench,etc.) greatly effect the numbers generated.

RedlineSS2000

Hey i just wanted to say that i have a set of bryan's heads on my car with a c2 cam from mti and on the dyno with my m6 i put down 432 rwhp through a 12 bolt rearend. So the guy does know what he's doing and i hate to say to the other guy that said he lied about the flow numbers. Man unless you have a sheetmetal intake that can flow 300 + cfm i dont know what your complaing about because a ls6 intake dont flow over 280 cfm unless some work has been done. <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />

REDLINEZ28

I know Bryan through Chris and he does some good work on heads if you want another opinion . Chris's #'s don't lie. Even if you did LS1 edit....who did it if the person in charge doesn't know what they are doing they can do more damage than good.

Hell the cam alone would almost give you 330hp.

Just a friend backing up some good work.

Hank

ps.
I'll have the $ together sometime for a set of LT4 castings Bryan.

Slowhawk

iTrader: (12)

You won't have an answer unless you do a leakdown and moniter the engine.330hp means something is screwed or very badly tuned.

C4VetteLS1

Hopefully you all realize i dont know brian neelend and im not attacking his head work. Im only trying to come to a solution on the cars low horsepower.

The car has the stock tune it right now. I have ls1 edit (as i run a chassis dyno as well) and i havent done any tuning because i believed untuned the car should at least be making 380 rwhp MINIMUM.

I will put auto tap on it and try and figure this problem out.

Whistler

iTrader: (46)

When referring to the "swirl ramp"... is this the area where the rocker arm bolt pertrudes into the intake port , or is this the area around the valve guide.

Every set of S2 LS1 heads I've seen has that bolt hole for the rocker arm ground open.

JFM-jr

iTrader: (23)

It's the area to the side of the guide.Alot of guys take that down and back a good bit.The area where the rocker arm bolt protrudes is the rocker boss.

Slowhawk

iTrader: (12)

I agree with the above about that the car SHOULD put out atleast 370hp in bad tune state.I would jump to the heads are NFG,but there is posts here of other people running the heads from the same porter.So I'm leaning towards the something else is wrong with the engine.Could be a blown head gasket,wrongly ground Cam,lifters are bleeding down too much,heavy exhaust restriction,Incorrect Dyno reading?

Angie

iTrader: (4)

If he has a Thunder Racing 224 cam, the cam can not be incorrectly ground. We check every single cam on our CamPro Plus before it ships to the customer. The cam card is printed out and has the serial number of the cam on it. The card is sealed inside the box with a label that has the cam specs written on it. If he received a sealed Thunder Racing box with the cam card, then the cam he has is what is on his card. We have developed this process to be positive, without a doubt, that our customers receive a cam that is within our specs for our custom camshafts.

Angie