I must say that there has been whole wealth of good information and lessons being taught in his thread. This only goes to show what can be achieved with hardwork and knowledge. Im jus starting out as far as motors go and have been learnng alot of the key principals through Bret and knowledge that he's willing to share with me just because thats the kind of person he is. Where as alot of engine builders out there who are so stuck up in themslves would give someone the time a day for simple questions. But Im probably rambling sooo......


later,
-john

 

Agreed

 

this is a first "you have to be **** to go fast" if thats the case i have friends that ought to be runnig 7's on a stock bottom 6cyl. and doing it NA at that. to bad he dont have the dilligence part.

 

Denny, nice results congrats!

I wonder how much more power can be had with a set of LT4 heads and intake?

 

Boy isin't that the truth.

Bret

 

you missed my point entirely.

the problem is that you are basing your idea of what is "average" just from the handful of guys on this board.

sure hes above average on this board........but that doesnt mean hes above average for what a properly built LT1 headed 383 should do.

JMO


and BTW.........im also guilty of the "slappin parts together" sin.......but im learning and will layout my plans better on the next setup.

 

Here's the flow numbers of these particular set of heads and also a response “what if they had been LT4’s.”

.100 63.5/55.2
.200 133/91.9
.300 193.4/131
.400 235.4/158.5
.500 266.5/178.6
.550 274.4/185.6
.600 272.4/190.9


Nothing special by any means but I was with Lloyd when he flowed them and there is no doubt as to the validity of the numbers.

I ran across a set of LT4 heads about the same time from another vendor on this list whom wanted $3,000.00 for them and claimed they flowed in the high 290 range. On Lloyds bench they flowed max @ 284 cfm. Even though the LT4’s showed a higher peak number, the average flow was identical on the intake and only a couple of cfm higher on exhaust using larger valves. Needless to say I didn’t pay the $3,000.00. I would have in a heartbeat if they were legit.

I’ve been hooting on Brent for playing with the Performance Trends software but I’m about to plead “guilty as sin” on all counts. Plugged the numbers for the LT4 heads that I didn’t buy along with a set of GTP heads that I used to own into the software to see what it said. The GTP’s flowed within 2 cfm of the XXXX xxxs heads and I had made 466 rwhp with the GTP’s on another 398ci motor I had done prior.

The software liked Lloyds the best and indicated they would give higher power ratings than either LT4 heads. But..... that's software.

I’d say both LT4 heads are probably more typical of what you see on the market today and the spec’s bumped up slightly for marketability. That said….. I did see the flow sheets from a set of LT4’s that Lloyd did with 2.05 valves that did flow over 300 cfm so better LT4 portings are out there.

According to the preliminary numbers my new heads flow about 30 cfm more on both intake and exhaust. W/o changing anything except more welding and porting on my LT4 intake, we are going to bolt them on and do everything we did before all over again to see what kind of power improvements are available from larger heads with larger valves.

After that we will start working on finding a cam that matches the powerband I have in mind. Then…… we’ll put in a new shortblock and guess what? Yep… all over again. But that's how you learn and really fine tune.

 

I may not have been clear on my prior post. The posted numbers are with a LT4 intake.

Nick Agostino talks the talk, but misses a few beats on the walk and origionally ported the LT4 intake. I gave Lloyd both the intake/heads and had him redo them. (read..... fix the suckers)

The LT4 intake may be a bit of an X factor here as Lloyd took them so far out that they had to be welded in a couple spots and are pretty darn thin in others. The intake may help more than I think as I've never been impressed with the results of ported intakes.

 

What alot of people dont understand is that lots of people (including myself) only had a mailorder tune when using Lloyds heads and my XE230/236 114LSA cam. My best pull with a pcmforless tune 368rwhp/336rwtq. Now, i had no laptop or software, so i just adjusted the fuel regulator manually to lean it out and bumped the #'s to 383rwhp/353rwtq by going from 10.0A/F to 12.4A/F. All it did was shift the A/F curve up, only tuning would have changed parts of the A/F curve where I had some dips. After about 1 hr of driving the compuetr compensated for the changes and i was back to 10.0A/F. I have no doubt in my mind that i could have hit 390rwhp/360rwtq with a proper dyno tune (A/F and timing adjustments).

Moral of the story, the guys making big power (stock bottom or not) are the guys that dyno tune!

 

Bingo!

 

There are no such things as "freaks".

There are cars that were put together properly and ones that weren't.

 

I totally argree with Joe here. There is waaayy to many "haters" in here. A few people put together REAL setups, that have had many many hours of thinking and assembling, all of a sudden you puting out "UNREAL" numbers. please....Denny, Huge congrats on the numbers and results. Its good to hear that all the sweat blood tears, and hard work from yourself and others has paid off. And your flow numbers are a big slap in the face to all those "WHAT DO YOUR HEADS FLOW?" head gurus. Im getting ready to ditch my setup that I purchased from TPiS, and frankly im not very happy with the results. 383(10.5:1) AFR 190's(Intake 66,138,204,247,272,275 Exhaust 56,103,144,171,185,196, in .100,.200,.300,.400,.500,.600) Im running their ZZX cam (240/240 .595/.595 112) cam. I am also running the Kook stepped headers and all the bolt ons ect.. I only managed to pull 390rwhp, but that is only with one session of tuning, although my AF is right on, and so is the timing. Dyno Graph I believe my 52mm tb is killing it, not to mention I am running LT1 Style Heads, with a LT4 manifold! Im also catted, and 12bolted. But anywho...big congrats!

 

yep..I agree also. Its the people who put the extra time and effort in their setups are the ones putting out the above average power. You can't just throw a bunch of random parts together and make power..and what works for one may not work for another. Same thing with a motor..you can take two identical motors..throw two different heads on them that flow about the same on the bench...and they won't make the same HP. Also.. lower "bench flowing" heads can outperform higher "bench flowing" heads on the same motor. I was always asked what my old heads flowed..I just said 10.9s at 125. People were shocked that I didn't have a flow sheet on them..lol. Turned out that they flowed in the 245 peak range...but we all know it isn't about peak numbers..or flow bench numbers for that matter.

Congrats on the numbers man...looks like a very fun car to have on the street.

 

Denny, with all the dyno time your car sees do you think we can see a video? I'd love to hear it at idle and of course at WOT Better yet an in car video with you ripping through the gears would be awesome!
If you can swing it that would great!

Thanks

 

OK: that wasn't too hard was it?

You see, when someone posts " I just dynoed 1000 hp and did the quarter in .5 seconds in my 350 (and neglects to add that "oh yah, that 350 was in a go-kart, with twin turbos on the juice and was manufactured and tested by GOD) it often will result in a lot of responses like the ones here.