which one would you prefer, pros and cons. The car is going to be a street-race show car. Thanks for your time...getting ready to order engine. My 2 choices are Gilbert chevrolets new 502 W/700+ HP range and Scott Shafiroff 540 HHR/700+ HP range. thanks for your time.

 

The 502 is a high com., big lift & duaration cam,ect on the street it may not play nice. The 540 is less radical. I would go 540!!!!YOU LUCKY DUDE

 

DOn't forget Reher-Morrison.. They have some real neat goodies too.

 

http://www.ultrastreet.net/engines/582_classic.asp

Low deck block and H-roller

 

540 the tq will be nice on the street. I used to run a 632 on the street and loved it

 

The 540 offers the same power in a much more streetable package plus gives you room for the "growing pains" that usually start within the first year...
-Patrick

 

The old saying...
" there's no replacement for cubic displacement !"

502 doesn't sound big anymore. 540 does.

The 540 will provide you a much bigger smile on the street. It'll be much tamer and easier to drive, yet still unleash one hell of a neck snapping adrenalin rush if you can hook up (and hang on :o )

Scott shafiroff has a very good reputation, even here in OZ.

 

If I had parts available which made one combo significantly less expensive to put together than the other, that would be my choice. (That's why I'll be going 496.) Otherwise, I'd go with the 540.

 

If you're gonna' back-half the car, then maybe a 540 would be the way to go.... But let's face it- 600HP or 750HP, or 1000HP.... what difference does it really make?

IMHO, your decisions about the rear suspension and transmission, should determine what engine you're gonna' have under the hood... If you're looking to keep the rear-end essentially stock, then even a 600HP 496, to a large degree, will be wasted money, simply because it'll be a big smoke show. A 540, with 700HP??? Ok, the cloud of smoke will be a little bigger, that's all...

If you leave the rear-end alone (with a 600 HP engine), with "street" tires on, then the car will get away from you, and you're gonna' crack the car up... It's not a question of "if," only "when."

If you try and hook up even 600HP, put the stickies on, without spending some serious coin to beef up the rear and transmission, *something* is gonna' break. And honestly, the possibility of having a half-shaft give me an enema at 50 MPH is something that does NOT make me feel... warm and fuzzy...

I'd suggest backing off a bit, and deciding how *much* of a street-race car this is gonna' be... If it's going to be a full-on race car, then go with a 540, or step up to the tall-block, and consider a 632. But if you aren't going "all the way," to make it a race-car, then I would suggest looking at what the limitations of your car will be (with regard to strength, maximum torque of the trans and rear end), and getting an engine that is appropriate to those limitations...

Good luck!

 

Bigger is better!

555's are even better than 540's if use the right heads.

Making 750-800Hp with a 540 is pretty basic stuff these days.


My only advice would be to forget everything you ever knew about what it takes to build a *street engine*. TQ will never be an issue with 540 cubes,,,so don't kill it with small heads, cams, intakes and carbs. The specs you are used to seeing are from 350's to 454's. Add 100 to 200 cubes to the mix and all of that stuff is worthless.

Design it to have *less power* under 4000 rpm...trust me..it will still have 675-700 ft lbs......and then have it where it can really scream to 7000+ RPM. The parts you use to build these things can easily handle it...so you just have a measly 700 ft lbs when riding around...but when you really stuff your foot in it on a nice section of road...and twist it to 7000 rpm......well it's a LOT of fun!

If you build it to be done by 6000 rpm..you will find that it accelerates so quickly from 3000-6000 that it's worthless. Build it to be able to twist some.





JIM

 

A lot of wisdom in the last two posts

It does not matter what it is if it cannot hookup without breaking

The price of a suspension/transmission needed to handle a good 496 will also handle a 540+ but if you don't pay that price and make the right mods everything you spent on the motor is wasted (unless ego and dyno numbers are the goal)

 

Sorry, but I have to disagree. What gears are used, the suspension setup, the tire diameter, the distance of the track (for drag racing), full-race versus street-strip versus pure street, etc... ALL matter, not just max RPM.

 

A fascinating thread! What would you guys recommend for me? I have a '69 350 but miss the torque my '73 454 (I had dropped a LS7 into it...).
I want to tidy up the rear-end, but make no major changes, and relative "normal" tires. Not a street racer, just fun. Maybe an overdrive trans (it has a manual). I'm starting to think I should stay with a 454?

 

For the kind of cars we're talking about..traction is almost always in short supply with this much motor. The idea is to give up some of the overabundabce of low end power and move it higher in the RPM scale so it becomes more manageable. When power is in this range, there isn't a giant difference in street, street strip etc other than if you limit the RPM. When you do...your 540 quickly becomes fodder for much smaller motors. I'm not saying build a banzai grenade motor. In fact...using a larger, yet less aggressive lobe can often help longevity of the valvetrain. Typical Hyd roller will go into valvefloat quickly in motors like this. The valves are heavy...and again...these things WILL rev! There's a lot of pressure pushing down on those pistons which often weigh less than a 427 piston by far, the weight of rods are essentially the same as well as the crank. Why wouldn't it rev?

The first version of my 540 made 732HP at the crank and 615 RWHP@6200 rpm. It was fun to drive...as long as you liked tire smoke. You could drop to 3rd gear (3.36's) at 70 mph and literally light the tires up into rolling smokeballs and skate all over the place. Problem was that when you mashed into it at 3000 rpm..it was going past 6000 rpm in about a nanosecond. And when you hit the next gear..instant spin again. More like a drift car than anything else.

The next version of the motor used same shortblock and heads, yet heads were ported (and to listen to some folks...were already too big!), a much larger intake was installed and a larger cam. Same carb. The power was then 825HP at 7400 rpm...which was higher than I wanted it to peak. The heads turned out better than we expected and the cam was too large for my gearing combo. Great cam if I had geared it to cross the line at 7800 rpm....but not great for the new 3.07's I use now. I now run a slightly smaller can and it peaks around 6900 rpm and I cross the line at 7500 rpm. With a cam between the small one..and the large one....I hit the magic spot for my heads and the motor came alive. I haven't changed it in years.

But here's the part that may help you understand it better. With the *too big of a cam*it still mades essentially the same peak TQ (just under 700 ft lbs)..but it does it at 5300 rpm instead of 4600 RPM. The TQ doesn't fall off and at 7000 rpm it was making 231 more HP than the first version was making at the same RPM..and it was still climbing. With *only* 500-600 ft lbs at 4000 or so RPM instead of 700...I have a much better chance to utilize the power. It's not an issue on the street..you only use as much as your sanity will allow you. But when you want to really rock...you can let 'er rip!

If you've never driven one of these things..it's a lot different than you might expect. I have a couple of buddies who built theirs to the *Hot Rod Magazine* mentality of *TQ is everything* and regret it. Our cars have very similar manners on the street...I mean I ride around with 3.07 gears...how radical can it be? Yet my combo will flat walk off from those others because they are out of steam too early. TQ is great...TQ over a VERY broad and usable RPM is better! Otherwise these things become really nice motorhome and tow truck motors. Might as well build a diesel!


Just my .02
JIM

 

 

i'm thinking of g-force G-101 4 speed vs GF-5R 5speed. I'm looking at Shafiroff's 582 HHR. What do you recommend? The car is in the process off frame-off. Van Steel did the frame and upgrades. Its a show car with limited track with the car club. Thanks for your time.

 

Well, that falls right into what I WOULDN'T buy. 700 ft lbs at 4500 and 765HP at 6000. Exactly the type of powerband I wouldn't want. Look at it...makes same TQ as the first version of my 540..though at a slightly higher RPM even..and it's already running out of breath at 6000 rpm. It made 33 more HP than my first version did at LOWER RPM..which is to be expected...it has 58 more cubes.

So how do you figure it will act at 6500 rpm? It will be nosing over like crazy. You better grab gears fast.

The GForce transmissions are great. Some of the best customer service in the industry. I like the GF5R in mine so I can run 3.07 rear gears for cruising and still make up a lot of the poor overall gearing up in the trans so I can have good acceleration.

Might check around for dyno numbers on the UltraStreets from anyone who actually tested the ones they got. I know of two 800HP 540s that made just under 700 on the dyno I regularly test on. The second one was the replacement for the first!

What kind of track days> Drag strip playing around or road course? Any of these will be insane on a road couse and a HR will not like the RPM that usually accompanies them.

JIM

 

I second Jim on the Shafirroff engines. My engine builder dynoed one of the 690 hp motors and it only made mid 500's. I believe this dyno as well since he builds race motors in CT and can't afford to build motors that won't deliver the times.


Bill

 

I agree with Jim. A lot of guys are hesitant to build or buy something like he is suggesting, but end up wishing they had in the first place. An engine like he is talking about ends up being more streetable because the power is usable.

I would go 555. Reher-Morrison makes some nice engine.....Wolfplace over on the Chevelle Forum seems to have a good reputation if you were thinking of a custom builder

 

I purchased a Shafiroff 540/625. I have issues after only 400 miles.

1. They gubered up the intake gasket upon installation. That caused a gallon of coolant to be dumped into the $13,000 motor.

2. The intake gasket was actually blocking the intake ports of the cylinder head.

3. Because I got it repaired, that cancelled the so called warranty.

4. The warranty. Shafiroff warranties nothing. They have outsourced this to an insurance company that throws very inventive administrative roadblocks to prevent you from making a valid claim. It covers only $2,000 of valid claims. Not much on a $13,000 motor.

5. Now that the intake gasket has been properly installed, another problem has arisen. The engine is now dripping oil from below. I don't expect a good end to this new issue.