I agree that we'll need to agree to disagree. What I'm hearing here is that no, you have not built one of these engines. It's not rocket science to me at all - I've just had different experience than you have doing top-end swaps on relatively mild bottom-ends. A circle-track engine is not a street engine, which I expect we can agree on. I'm also sure you understand the difference between dyno numbers and what's achievable in the car. And the difference between "mild porting" and a stock head.

The first build is dyno numbers, the second build didn't use Vortec heads ("We selected the cast-iron CH350C Lightning cylinder heads from Enginequest") and the 3rd ad has no details on the cam other than "CompCams custom". Ads are great - people buy based on numbers like that all the time and then wonder why they don't see it at the rear wheels.

I would also not follow your suggestions, as you're recommending .522 lift with a spring (GM ZZ4 - 12551483) with max lift of .525. This wouldn't be acceptable in one of my builds and I don't use the ZZ4 springs, period. Also, the cam certainly wouldn't be my recommendation for a street engine. Glensgauges recommendation is more in-line with what I would suggest, subject to more information.

Magazines are one thing - practical experience is another. We're coming at this from opposite directions and so with very different perspectives.

 

The first build IS dyno numbers... L31's hitting 440 streetable horses
with minimal preperation... So my point/arguement has turned out to
be 100 percent correct....amazing Im not trying to pretend I was
talking about rear wheel horsepower to save face like you... now that you've been proven wrong.
You're comment on the 2nd build using the EQ Vortec heads is interesting for such an "experienced" guy....dig a little deeper on that part number and you'll discover they are the EQ Vortecs...Same
chamber size and same runner size as L31's..same raised runner Vortec design-same basic head.. I've got 2 flow charts show them not flowing as well as the L31's... still hit 440hp-with WORSE heads. The EQ Vortecs and L31 Vortecs are similar to GM Double Humps and World S/R's...same basic head..different manufacturers...negligable differences.
Speed O Motive is building 450hp crate motors with L31's.... something you said was an exageration.

GM Part # 12551483 springs are the springs used in the GM
LT4 Hot Cam Package, not just the ZZ4, .... and the LT4 Hot Cam lifts to .525... So, You're smarter than the GM Engineering Staff by suggesting they are a bad choice for a .525 lift cam.... comical

Billa... have you ever built a real engine??? or just played with
Desktop Dyno.. the 3 engines that thwarted your suggestions were
real engines on real dyno's....gimme a break..your cam suggestions
are good for people who want to be down 100hp for not doing their
homework.

 

Ah, so we enter the realm of personal attacks. So, I'll sign off.

Not at all - my point isn't drivetrain losses, but simply that dyno numbers aren't attainable in the chassis with waterpumps, alternators, etc. attached. Easy to make big flywheel numbers at the dyno - I generally deal in what's attainable between the framerails in a real car at the flywheel and what actually shows up at the rear wheels.

I did read the article and surf the heads - they're not the stock Vortecs, simply based on the same design. This could also be said, for example, of the Word Sportsman II's of '462-type heads - but the flow numbers *are*different.

Again, you reference an ad with no personal experience - you've never bought or installed the engines, correct? You want to read the magazines, ads and specs and profess being an "expert" - when you're just parroting what you read.

In regards to the ZZ4, it's well known in the LT1/LT4 camp that yes - these springs ARE a very bad choice - check out the LT1 and associated car forums. The General stopped at .525 lift and built the associated parts to that spec because the stock factory GEN II lifters are not long enough to support anything more than that. As a "factory" upgrade, they needed to be careful and offered a "trunk kit" that would give more "oomph" without breaking anything...not a max-performance option by any means. I'm building a HOTCAM 383 LT1 right now slated to make right at 400 HP flywheel - which is right for my budget and intended use in my '95 Impala SS.

Yes, I've built literally 100's of GEN I, getting started (late) in GEN II's and have a pullout GEN III on the floor in my shop. Here's a picture of me installing a cam in - oddly enough - a GEN I, stock Vortec head engine I built for a buddy. I'm heading out this Saturday to start a teardown on another GEN I, and I'll be starting shortblock ***'y on my 383 LT1 this weekend.



I absolutely don't position myself as a racing engine builder - I'm a budget builder and I've built few engines that have made more than 1.2 HP/CID and very few that have made more than 1.4. But in doing so I've learned the realities of what's possible...and what just looks good in print and in ads.

I've asked a number of times if you've ever actually built an engine, or if you just read the magazines and parrot what you read - but I still haven't heard anything about the engines you've built. I generally find that those with credibility focus on what they have achieved and try to learn and teach based on their own experiences. Those that have no credibility always refer to others' work as demonstration of the "points" they're trying to make.

Apologies to the thread for taking this so far off-course and to the thread starter that was just looking for a little advice on a top-end swap and ended up hosting a pissing match.

 

I've been building engines over 20 years... 3 of those years
professionally at AER in Dallas, Texas and at Reher Morrison in Arlington.

A head that flows 238cfm, like the L31's, simply needs tuning, cam,
and exhaust to make 450hp on a 350.... that's the bottom line..
and if you're not getting there it's your tuning (cam,carb etc.) choices that aren't getting you there.

The GM springs I mentioned are an excellent choice for cams
lifting under .540.... bottom line. No phantom lifter problem off of
a Gen II motor changes that (by the way, the L82 is a GEN 1 motor
and doesn't have the roller lifters you mentioned... another smoke
screen)

You can make 350hp with Double Humps and L98's with exhaust and a cam... a Vortec upgrade is a waste of money if you're going stay at that power level.... pretty simply, you've tossed money away on heads you didn't use.
You've thrown 100hp away because you didn't cam for the better
heads... but this is EXACTLY what you suggested... sad. Having a pic
of you standing by an engine is what?? an attempt to show expertise?
Show dyno sheets on a motor you built producing HP to the head's
cfm potential and you've proven you understand camshaft selection
instead of just assembly instructions.

 

Great to hear you're actually an engine builder and building professionally - although I have yet to hear about engines you've built in particular. AER is-> http://www.apspowertrain.com/? Not exactly building high-output engines. The question remains: have you, personally, ever built a high-performance Vortec-head GEN I with the configuration you're recommending?

450HP...on the dyno. Means nothing.

We'll have to agree to disagree on the ZZ4s - based on personal experience. And - no phantom GEN II lifter problems; GM notes this as did CarCraft in their review of cheap factory roller builds in the last issue. Not sure why mentioning this is a "smoke screen"

Man, it's just all about personal attacks isn't it. The rest of your post is such a useless mishmosh of information it's hard to pull anything out of it. The right build is a build that meets the intended usage and power targets, not one that makes maxiumum power. Might not be true in racer-land...but it's definitely true on the street. And I think this is where our disconnect is.No disagreement at all that it's all about matching the cam to the intended use, and the heads to the cam - I just don't see that what you're recommending matches that.

And your picture of an empty flow bench is intended to show what?

So, let's drop it unless you feel you have something else to "prove".

 

Wow ... I began engine/machining work at AER and worked machining and assembling 460 SV0 motors per our contract with Ford... and Big Block 502's per our contract with Mercruiser.. I then moved to Reher Morrison doing Block machining and assembly and head assembly..
The crux of AER's business is contract remanufacturing for the Big 3
and Mercruiser.
The Superflow pic is from 3 years ago.... the dirt team I was
wrenching for at the time picked the machine up used and still has it today..it sits in the corner at their private shop... where I still go
when working on my own engines.
The last Vortec engine (L31 heads) I worked on put out over 500hp on a 355 cid Chevy and had extensive porting... they flowed 270cfm.

I've certainly attacked your suggestion that Vortec L31's can't
make 450hp for the street.... suggesting they can't,won't, or are impractical in such an application is pure They flow 238cfm with
170cc runners in stock form..this should have stopped you.. Likewise your suggestions on LT4 HotCam springs being a bad choice for .525 lift cams...also pure
Directing you to 3 different websites where 3 different builders
built 3 different 440hp plus Vortec street engines didn't seem to even
make you take pause.... I guess I shouldn't bother telling you things you don't want to hear by siting websites that provide veryifyable evidence.... or dyno numbers.....A stronger measure of veryification... because you won't listen to things you don't want to hear.

You said "450hp on the dyno means nothing"..... Really?? That was the entire point

So long Billa... when dyno numbers mean nothing it gives me
a clear pic as to what kind of person Im talking to.

 

So long, Kyle. When dyno numbers mean everything it gives me a clear pic as to what kind of person I'm talking to. And, I note in closing that in response to a simple question if you had ever personally built the engine of which you speak...you failed once again to give an answer.

Now that's : talking

 

Logic would dictate if I built a 500hp SBC with L31's and a 355 that I would know the formula to make 450hp with L31's and a 355... your question was answered... but it didn't register with you anymore than
any of the other facts you ignored.

Maybe you should take your "Dynos mean nothing" ideas over to NASCAR row in Mooresville,NC and tell them to 8 or 10 engine shops over there...
Im shure they'd be very pleased to find out that they were wasting
their time with Dyno numbers and testing and would be better off
hiring you to be their seat of the pants power detector guru.

The sad thing about that idea is that I met some of the Cup builders
at Reher Morrison when they were having Head Development Work
done there... so Im thinking your going to get a chilly reception.

 

You never said you "built" anything. "wrenched on", "assembled", etc. So...the answer is "no" as I suspected.

As you just still don't get - how does a racing engine apply to building a streetable Corvette engine? Boy - talk about ignoring facts. Do a little search on how well those dyno numbers match what's between the rails. Do a search on the 260HP and 290HP GMPP crate engines by the time they have a water pump, alternator, small-tube headers/ram's horns and a full 2-1/4" exhaust. So yes - dyno numbers mean nothing for street engine building. Big dyno numbers sell magazines, sell parts and disappoint buyers when they find they're missing 20%+ of the power quoted...by people like you.

 

A dirt motor I co-assembled with my teamates... rock on Billa..
sorry for confusing you with the facts.... you know it all... and I
know nothing... sorry about your your water pump ideas and such
..

 

Nope, you have a ton of knowledge and I'm sure could teach me more than a few things about professional assembly and racing engine design. Unfortunately, you're not willing to consider that perhaps YOU don't know it all and that racing engines are a very different beast than street engines. I'll stand by my original statement that the Vortecs are great upgrades for a mild street build making < 1.2 HP/CID at the flywheel. Beyond that, the GMPP large-ports or an aftermarket is a far better choice.

Tell you what. I'll build an L82-spec shortblock, and you'll build up a set of STOCK CASTING Vortecs and select and provide a flat-tappet hydraulic cam and valvetrain. The resulting engine must idle at 850 RPM with a stock converter and provide sufficient vacuum to run C3 accessories. We'll share the cost of an engine dyno session with standard C3 accessories including water pump, alternator, fan clutch, stock exhaust, etc. If the engine makes more than 450 HP you keep the engine; less than 450 and I keep it. Valve float below peak power or any valvetrain failure is an immedate forfit for you. Engine build to be dyno'd no later than 12/1. Probably need to work out a few more details...but interested?

 

Play nice guys.

 

You two have gone so far off the project scope here it's not even funny (any more). The original request was with a stock lower end. KD - all of your examples were specific built, definitely not stock production hardware. The flow numbers you suggest are 10%+ higher than actual for a base L31. Out of the box with .480 max lift retainers are already hitting v/seals and guides.

This I know with my 20+ years as an ASE Master Machinist and 15 of those as a Dyno Joc at FP!! I may have built just a few engines over that time including O.E. prototype Ram 5.7-6.0L Hemi, Ford 4.6L, 5.4L , 6.0L GT40, Viper V10's, and a few 6.8L V10's. Oh yeah were talking Chevys here! Well those NASCAR guys, were talking to us 6-7 years ago when the SB2 weren't even legal to use yet!! Did I mention FP was the official gasket of NASCAR? Mercury Marine back in the day was sending us pallets of 502's, they were lined up down the hall at one point. So basically, more multi-platforms than just circle track stuff.

But lets forget all that and get back to the original posting question. The original Vortecs have been proven as great baseline for replacement and power, for the money. No porting, no head shaving, no 1 3/4" headers or high rise single-plane manifolds with 750+ CFM carbs jetted like it's a 1000 CFM. You just bolt them up and instantly gain some power based on flow and the increase in compression (switching from 76cc to 64cc). Comments from others stated cam replacement "while your in there", I'd second that but not the specs you two are listing.

We have to remember the realistic requirements of the average power hungry Vette owner who doesn't have a killer bank account backing their projects but wants, no needs to up hold our Chevy/Vette banner. After all we have a target on our backs as the car to beat at every stop light.

And Billa, without that dyno research time, you wouldn't have the quality nor quantity of parts we have today. Not all dyno runs are just idle to W.O.T. and then shut off. O.E.'s and suppliers are required to meet time and test cycle requirements years before you even read about them in a magazine while on the throne.

Let's just get along and help the brotherhood in protecting the icon we admire so much.

Later.

 

Exactly the recommendation I posted - read my first post, which I believe you've overlooked. Very practical power with very practical upgrades - my posts have always been focused on exactly the upgrade you recommend.

And - I never - ever - denigrated dyno research time. I simply stated that dyno power figures are not a good guide to installed power.

I agree it's gone way off-topic, but my focus has always been on realistic power for a street, daily-driven Corvette.

 

No, didn't overlook your post, just wasn't referring to you specifically till later in the post. But you had to go there anyway, go pat yourself on the back, you deserve a cookie.

 

Billa. I understand completly where you are coming from on the Street Vs Race engine argument. A lot of times people post advice that will pull higher power (dyno #'s) but at a sacrifice to streetability. Here is one of my old posts. "Bigger is not always better." You will find it informative and humerous at times. Been there, argued that. http://forums.corvetteforum.com/show....php?t=1608090

 

First line of of your post:

"You two have gone so far off the project scope..." Who were you referring to?

Thanks for the cookie - it's delicious!