32valves

'cause it has been done on race gas already.

DDSLT5

Fair enough!

LT4POWR

Got a link or some info on him? I'm in OK and never heard of him. Also, on your setup...should be a runner

locobob

Greg works for Mercury Marine and was involved with the LT5 program back in the day, he does machining and port work as a side job. I can PM you his email address if you like.

Looking forward to seeing the results of this project - should be a real runner.

LT4POWR

Thanks for the info. I don't need his e-mail or anything, hell, I don't even have a LT5. I was just wondering about a fellow Okie. If he had a shop near OKC, I would've liked to stop by and check it out.

NITROUS JUNKIE

Ok guys here are some more pics of the Ihs in the first few steps..

Zr1 Destroyer

Cool pics of the IH's.....I have always kinda wondered how far up the coolant passages went in those or if the coolant even flows that high up into the IH.

I guess when you start that tpye of porting project you're comitted to the end!

Rkreigh

that's some pretty radical surgery there!! should flow plenty to keep up with that big moma

9's on motor???? that would be pretty amazing.

NITROUS JUNKIE

Yeah there is a ton of work on this top end...and a ton of money!!! 32 $titanium$ valves and retainers (OUCH!!!!!!)


As for flow we picked up quite a bit..with more to come with the finished ports etc..The heads are flowing GREAT...now we just have to get that much flow through the injector housings/plenum

One things for sure...the 'ol boy with his brand new Z06 Vette will be real upset when he decides to give the lil 427LT5 a run... Just an ol C4.

Peaven

Wow...that is going to be one brutal beast!

SAM/CH ZR-1

Just curious

For example: I have 2 engines with 427 CUI. A LT5 and LS7 (new Z06). Both are natural aspirated and most possible tuned. Which of both engines would be stronger?

Sam

NITROUS JUNKIE

Well the LT5 is a great power house...the old small block chevy has been hotrodded and raced for many years. The LT5 has its limitations, RPM being one of them, and only one head casting to work from, and only a few number of them being modified. On the other hand the old SBC has unlimited choices on blocks, heads, cams, intakes, etc...and about every hotrooder on the planet has got their hands dirty making horsepower on an ol SBC. Its hard to beat all those years of SBC racing.

I dont know what the max potential of the LS7 will be for N/A, but the set of cylinder heads put on the engine from the factory are outstanding.

When comparing the LT5 to a SBC....Hands down the SBC will easily take out the 32 valve LT5 (both being fully built)..There are so many combinations to choose from when building a SBC..
heads that flow 400 to 450cfm are not uncommon.

A fully built 431cid LT5..(Fastlane) around 900 hp

A fully built 358cid splayed valve SBC 958hp to well over 1000hp.. Much more power and a lot less cubic inches.



Here is a link to a real serious SBC...1100 hp all motor
http://www.racingjunk.com/post/64168...e-engine-.html

TONYDEE64

This info. should go over here real well...

FU

The truth is hard to swallow sometimes.

32valves

when discussing street cars which can make more power and offer good street manners might be a better question. Basically you can make as much power as you want with almost any decent engine out there because you can always strap a turbo to and crank up the boost. Where the LT5 shines is in the HP it can make with good manners. I'll bet it won't be too long before you see a 600 rwhp LT5 (with a bunch of cubes) with the stock cams (N/A). I don't think there is any other engine that will be able to do that.



Oh, and I disagree that the LT5 is RPM limited. Nobody has done what it take to get those RPM's.

4cefed

Why do you think that is so hard to swallow over here? I don't know of too many people in this forum that would disagree with his statement.
Like many people on this board my ZR-1 wasn't my first hot rod. SBC is a fine motor and the new LS7 will be setting the NA standard in the not to distant future.

bill mcdonald

Looks like cool stuff.

SAM/CH ZR-1

Is the power potential of a LT5 just limited because of its heads or because of its block stability?

Sam

NITROUS JUNKIE

It is VERY EASY to make a regular SBC have excellent "STREET MANNERS"..and do it MUCH cheaper than an LT5.. Bad manners and a well built SBC are a thing of the past for this kind of HP.

There are hundreds of 600+++ hp small blocks out there running on the street on pump gas. Stock cams or not...Who cares?? They are very reliable..excellent street manners.

The LT5 is a great engine but you dont need 4 valves to make big power..with the ol SBC evolution and newer design cylinder heads..they will out flow lt5 4 valve heads, and have high velocity...

Looking at the engine for sale on racing junk...1100 hp all motor (SBC splayed valve) and only 400lbs!!!! That will never happen with an LT5


You could take an lt5 head port it paper thin..pull out the valves...and they still wouldnt flow 450cfm...

Now lets take it a step further..I have a set of Big Chief BBC heads flowing 580cfm....got to love the 'ol pushrod engines..

NITROUS JUNKIE

I think the power is limited more towards the heads, lifter design, and cam chains. Ive heard of the block being an issue, for my experiance on the strokers...Ive never had any block problems.

There is a limited space for big valves, big lift, and runner size on the LT5..on the 'ol SBc they have moved the ports around so much, changed valve angles, in some cases reversed valve orientation (SB2)...

In the SB2 the port runners run right though where the head bolts usesd to be, they now run a short head stud that you have to run a socket and extention through the center of the port to tighen up, then the runner is capped of on the top with a plug. They also took the outer cylinders and switched around the intake and exhaust valves... With overhead cams you cant get away with changing runners, valve angles...etc

The pushrod design allows MUCH more freedom to modify the heads... Can you imagine how expensive it would be to try and recast an overhead cam head? Even if you could get it done you have those lil cams in the way.