Babolt, spent all day on the dyno and cannot get past about 460hp and 570tq. I am almost positive the problem is on the exhaust valve side. I am going to install the new cylinder heads asap to really figure out the problem. I suspect their is 150 hp missing until I do the heads. The fuel ratios all look good and no detonation so more air thru the motor is just what the doctor ordered. I will call you over the holidays to discuss, Chet

 

wow...

are you going to have to ask permission from the tower to do a fly-by?

 

It is the x-hast valve. It is too small for a forced induction setup. Dad and I were talking to Jerry Green at FFW in Ennis about this. He gave a annogie: "You have bucket that will hold 5 gallons of water. you fill the bucket to it's capacity with a 5in hole in a certion amount of time. but what happenes when you try to empty the bucket in the same amount of time, but with a smaller opening than what it went in with? You dont get it all out." So bassicly you are "burning" already burned air/fuel via not being able to get it out of the motor. Bigger x-hast valve = more power + Lots of money to do.

------------------
Thomas 'Lightning Boy' Shelton
SVTPerformance.com
BOARD MODERATOR:
-Dynos, Time slips, and best ETs
-Nitrous/Forced Induction

 

BUMMER! 38TopGun...bon a venture on you journey to the HP Land of Oz The Valve analogy makes sense...some kinda physics lesson..LOL

 

I met up with a buddy of mine, he's 20 years my senior, and my '66 Chevy is parked at hid place. He's been throught the max hp stage, and his mentoring me through my hp stage journey (I've had a few, and yes I know its Thrusday night). He told me that I'll get 2 to 1 return if I invest on high end HP. And to get that, is to invest in cylinder heads. We were talking about my 396, since he is a chevy man, and I like my 66 pickup, he wants to see it go fast.

He told me that there is a set of heads out there that will give me 70 hp over stock. I already have 325, NA. Then cam, I already have headers, gonna try to take advantage of them now...

He also told me about "C-C-ing" the heads. Thats kinda like blue printing the combustion chamber. We all know not all valves/rods/pistons/springs weigh the same, and blue printing them adds HP. C-C-ing the cylinder heads gets each cylinder to have the same exact volume and shape as the next, for much more even combustion.

I know you guys have thought of this, so how much do a set of aftermarket heads cost? For the 5.4L, I already know which Chevy heads I am going with...

 

Here's the stock #'s:
Stock '99 PI Heads
Lift Int. Ext.
200- 115 103
300- 148 128
400- 166 143
500- 175 156
550- 178 156

Ported and Polished '99 PI Heads (w/ five angle valve job).
Lift Int. Ext.
200- 95 88
300- 145 126
400- 178 150
500- 196 163.5
550- 202 167.4
600- 203.3 169.7


STOCK SVO HEADS FLOWED
Lift IN. EX.
100 55.7 47.07
200 124.05 85.31
300 171.41 115.37
400 190.79 130.64
500 202.71 135.84
600 219.40 136.81

Just curious what heads you were planing on using?

 

Finally someone to back up my claims. Ported heads or new ones, and a complete exhaust will make that bit@h flow like you can't believe. Awsome job on the truck.

Hey what kind of heads are you thinking about doing?
I was wondering what the navigatotr heads are like and would they work on the L's motor. Are the better? I don't know, but I know the navigator puts out 40 more horse then our motors stock. Just a thought anyway.

------------------
99.5 red lightning
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WORDS TO LIVE BY

 

It could also be a problem of the motor not using all the air.fuel its given. Might be blowing it straight out he exhaust! We have encountered this many times when building turbo bikes etc. For one the valve springs might be to weak. On a motor we are doing right now(a motorcycle engine) . It is set up on a superflow water brake dyno. At 6000 rpm the efficiency of the motor is 239% and BSAC(brake specific air consumption) is about 3500 grams per kw/hr.As we went up in rpm the efficiency dropped to 213% at 10300rpm..bu the BSAC went up to 4500g kw/hr. This is a true sign of the mixture not bieng used! JUST A THOUGHT.. has anyone checked seat pressure on these valve springs?
On the bikes when this happens its usually a gain of 40-50 hp once springs are installed!
38 I would like to hear more on your set up...very interesting. How much we talking?
best regards,
sebastian

 

JoeLightning
I think I can answer your question, 38TopGun has raised his boost level and that acts directly on the intake valve. In other words the intake valve has a harder time shutting when it is supposed to with more pressure behind it.
My thought on Top Guns problem is this, Has anyone checked the restriction (Delta P) on the stock intercooler? It looks kinda small to be flowin enough air for 550 to 600 HP.
Dale

------------------
Black 00'
13.21 @ 105.24 so far
full weight, stock tires

 

Chet
I just saw your post. I started to write a long reply but deleted it. I will wait for your call. I can say this much Santa was good to me today, I received a very cool 5.4L short block and everything else I have. I would like to compare flow data on your reworked heads and my reworked heads. It should be interesting. I plan to use an engine dyno to tune this motor.

------------------
BABolt
SVT#290

 

Thanks for all the ideas!! Babolt don't do it with the short block your hurting me!!!!The crank mfg hit me with a $20,000.00 bill for the first crank!!!!!!!!!! The others will be about $800.00 bucks a piece. The motor is not turning above about 4800 RPM. I was wondering about burning the fuel due to ignition reasons also but that seems pretty remote.The stock intercooler could definitely be a problem we are going to check for sure. We also think that the cooler may actully be collapsing due to pressure but once again kinda far fetched. Thanks for the flow numbers on the stock versus ported heads!! Can anyone tell me if the 4.6 modular engine is the same series as the 5.4? The camshaft problem at this point appears to be a royal pain in the butt. I am thinking about building ratio rockers for the exhaust side instead of messing with the stock cam? To much for my brain MERRY CHRISTMAS TO ALL!!!!!!!!!!!!!!!!!!

 

I am surprise at all of you.you should be smarter than this.after reading your post,I realize you are just missing the FLEX cappasiter

 

Steve
I compared the flow numbers you posted with mine. Do you know if there is a correction factor involved. Maybe the Ported and polished PI heads were Extrude Honed and they did not get the most out of them. Interesting data on the SVO head I would suspect the flow numbers on the exhaust side. My experience with them does not show such low flow on the exhaust side.
Chet
You should be able to provide the data for the SVO heads since you are using them. I would like to hear what you have for flow numbers stock vs. ported and polished.
P.S. Chet. Check with Edelbrock on there modular cylinder head development. There just may be a good 2 valve head in the works.
------------------
BABolt
SVT#290




[This message has been edited by BABolt (edited 12-23-2000).]

 

Great Job Chet. Of course I will agree with yourself and others that you need to flow more on the exhaust side.

N20boy, Your theory on springs doesn’t hold. I don’t believe Chet is raising the RPM at all. Certainly valve seat pressure must be increased when the RPM goes up to maintain cam authority, but if you don’t raise the rpm, why would an increase in seat pressure help?

 

"N20boy, Your theory on springs doesn’t hold".....I take it you dont understand the example I posted? Has nothing to do with rpm..as the kind gentleman said its about boost effecting the valve springs. Could be a case where valvesprings are
loosing control over the valves, actually
about the same as having an extreme amount of overlap it blows the air out without using it to the full extent. Just a thought..thats all

Bad as L- You might be on to something here as well. Im thinkin really hard about turbocharging my L. Maybe a twin turbo system..using 2 twin flow turbochargers. Ive check and there is plenty of space for a huge intercooler dead smack in front. I can tell ya this the HP numbers and torque numbers will be awesome. Hope santa drops off a intake plenum


[This message has been edited by n20boy (edited 12-23-2000).]

[This message has been edited by n20boy (edited 12-23-2000).]