Big-DEN

Erick, you got me, I was quoting numbers from higher compression, not quite 16:1
but think about it:

425rwtq out of 346's is about 1.40 TQ/CU IN - happens all the time

510rwtq out of 408's is about 1.40 TQ/CU IN - happens all the time

530rwtq out of 427's is about 1.40 TQ/CU IN - happens all the time

I thought 650 TQ out of 500 CU IN was low and should be closer to 700TQ. Its more akin to a situation of a 346 that is right around 395rwtq. Were doing alot better than that now adays.

Not knocking the product. not one bit, and we know you get your hands dirty alot.

racer7088

Your math is a little off Den. Those figures you are giving up there aren't near 1.40 TQ/CU IN they are more near 1.25 TQ/CU IN. Also remember taht the SAM 500 inch deal is not at a really high compression again.

With the normally higher compression that many people run actually on LS1tech here the SAM 500 inch ERL engine would have made even higher TQ but its a very safe engine in the mid ten to one range.

Is that right Gray I can't even remember?

Big-DEN

Eric,

For my RWTQ converstion to get TQ/CU-IN I used 12% drivetrain loss thru a stick.

So I'll let you look at the math:

425rwtq out of 346 cubic inchs = 425rwtq/.88=482TQ

482TQ/346 cubic inc = 1.395 TQ/CU-IN = 1.40 TQ/CU-in
--------------

510rwtq out of 408 cubic inches = 510rwtq/.88=580TQ

580TQ/408 cubic inches = 1.42 TQ/CU-IN
--------------

530rwtq out of 427 cubic inches = 530rwtq/.88=603TQ

603TQ/427 cubic inches = 1.41 TQ/CU-IN
--------------

Now we know I dont have a shop. I dont port heads, but the math was right on here.

These numbers are normally out of engines that are between 11:1 and 12:1

Go to 14:1 and perfectly tuned intake/exhaust side you might have 620TQ out of 408 cubic inches.

I believe your 1.25 TQ/CU-IN came from doing the rwtq/cu-in or 425rwtq/346 cu-in = 1.23 RWTQ/CU-IN

510RWTQ/408 CU-IN = 1.25 RWTQ/CU-IN

530RWTQ/427 CU-IN = 1.25 RWTQ/CU-IN

I was using TQ/CU-IN, you did your math with RWTQ/CU-IN...

Have a good one Eric.

racer7088

Sticks aren't that inefficient always. We have gone from the engine dyno right into the car an never lost that much power. Now an auto with a big converter is another story. Find some real engine dynos of mid or high 10 to 1 LSxs making 1.40 TQ per Inch and let me see them and I will give you a little slack.

I know you mean well but I have seen hundreds of engine dynos and yet not seen the TQ numbers you are talking with real pump gas stuff about so just letting you know that but I don't mean to knock you because if you thought this was true then I can see where you are coming from. Normal pump gas stuff averages less usually. The proof of the pudding will be when this car goes down the track and you can compare it to that 427 you were talking about.

Big-DEN

Eric,

Both of us know you can find 100's of dyno graphs on the LS1 side with:

346's at 410-430rwtq on dynojet and 450-490TQ on engine dyno
408's at 500-520rwtq on dynojet and 570-610TQ on engine dyno
427's at 510-535rwtq on dynojet and 580-630TQ on engine dyno

Now as far as someone who took it off the engine dyno, put the engine on the car
and ran on dynojet right after to show us theres about 12% loss for MN6 and 20% or more for automatic, not too many of those.

racer7088

Big-DEN,

Seriously I am not picking on you but find me simply one engine dyno of an true pump gas LS1 408 thats under 11 to one making 610 ft. pounds of TQ on pump gas? I am not saying it can't be done but I have never seen it so far. You've got to be able to find at least one!

You'be surprised at how many "race" engines don't even make that 1.40 FT LBs of Tq per inch!

Big-DEN

chit eric, now you have me doing some work.

racer7088

Big-DEN,

Yeah but if you find it I will believe you! These LS1s do make better than normal TQ quite often but I hadn't seen stuff that good myself ever, This doesn't mean it's impossible of course but I'd just like to see it myself from a good source with a real dyno.

Big-DEN

OK eric, these LS1's suck. They are a poor architecture. The original head head a wierd cathedral port.

They copied off of other architectures and then that they are not a good copy.

They use a weak aluminum block, and people have to hack them for odd sized bores of greater than 4.125".

I dont like how those rockers look.

IM trying to come up with negative responses.

racer7088

Big-DEN,

Don't try to come up with negative responses, just try to come up with that dyno sheet.

briannutter

The engines going in the car with an automatic and a smaller stall converter..We'll see chassis dyno numbers soon....no sense in guessing. I'm curious to see how it performs against typical headed 427's and 454's...especially down low. Hopefully we'll get some power numbers further down the scale than the 4500rpm the engine dyno can handle now.

Check out the Linda's (Jud's wife) black camaro under www.samracing.com "team SAM" section. With the current 375ci ls6 headed motor making 578 engine dyno hp, it's run 10.50's with full interior/automatic. It may go 9's with the 500 making 700. Knowing Linda, she will.

Oh yeah...I also want to see a video clip of it at the Jiffy mart in Houston...idling tough and getting a tank of 92 octane then pulling up to an intersection and yanking the wheels a couple feet at the green. If Linda doesn't do it for legal reasons, I'd be willing to eat the ticket.

Is there anyone in LS land running 9's N/A pump gas in a full weight daily driver? The target market for this buildup? Sounds like we could have a race between titans!

racer7088

I have two knocking on the door but I think the SAM/ERL 500 incher will simply knock that door down!

briannutter

Hot Rod 2007 drag week. Small block NA class. 10.7's out of last years winner. I think that numbers going DOWN!

Quickin

Just curious about something: Since there are no heads for these engines, YET, as far as cfm is concerned, to accomodate the cfm that 500 cubes can dish out.....how many cubic inches of the 500 are a waste, or not able to be used?

Is there some kind of formula that will tell you how much cubic inches are lost, kind of like flowing a set of heads....and than flowing a given intake with the heads. ie: The LS7 intake holds the LS7 heads back, so the LS7 heads with an LS7 intake makes quite a few of the cfm's of the LS7 heads in a way....a waste.
Or putting LS1 ported heads on a 427ci.


.

briannutter

If someone here has an engine analyzer pro or better yet...actual dyno numbers , it would be helpful to run a sim as I'm going to make a vague statement. Hopefully I'm not thrown off the forum as a result. As a VERY rough estimate, take the piston speed of a given cubic inch engine that produces a given amount of power at a given rpm. Change the stroke of the new combo, then raise or lower the rpm to match the point it makes the same piston speed. That should net you a "decent" idea of where the new displacement will make that same power. What makes the concept goofy is it doesn't really take into account intake or exhaust runner lengths and the rpm they are tuned for, but most people haven't optimized those to begin with. I won't get into cam timing as I'm still looking for answers.

All that being said, there are quite a few heads available that can take advantage of 500ci. It's not a "waste" at all. The added displacement merely lowers the rpm point a given set of heads/intake/cam makes peak power. Often, the hp number is similar even though displacement and "torque" are not. If you take a look at the 703hp at 6400 rpm power peak, then look at some of the horsepower graphs where the 500 was turned to 7300 (thanks Carrillo)...the power didn't "fall off a cliff". It also had the side benefit of lowering the RPM range to the point the valvetrain is stable with relatively inexpensive parts..which can help power by itself. A lot of racers will shift at the point where horsepower averages the best between the spread of two given gear ratios. If that's the case, shifting the 500 at 7000 is no big deal at all. Give it a large solid roller, the sheetmetal, and about 16:1 and it will pull a LOT more RPM than most people expect.

First things first though.

-Brian Nutter

racer7088

This 500 inch engine will make more average power than the 427 will, not less. No one cares about specific power unless you are racing brochures. The most average power to the wheels make you fastest. The bigger engine will make more power out of the same heads 99 percent of the time. With some of teh bigger LSx heads like the C5R the smaller engines can't even fully utilize them.

If you want more hp per inch than build small but if you want to have more hp go big. 500 inches is about as big as you can go! The heads start becoming more of a limitation on the bigger engines which means you can run larger cams and/or just enjoy more power but lower down in rpm with the same cam.

racer7088

I agree as this is what I see all the time usually does happen negating the tuning changes you alluded to. I see big 4.750 stroke BBCs do this all the time making 900 HP down at 6000 rpm where you can really use it. They have 450 CFM heads and at 632 inches they can turn it all into power and at a reasonable rpm to boot! Again these heads would be a waste on a street 454 BBC.

Big-DEN

Eric,

Was doing some browsing around. And what was funny to me is I saw one of the 300ZX's with a LS6 transplant.

The LS6 fit amazingly better than the 3.0L non-turbo motor.

Wife has a 268HP 3.5L v6 in the Toyota. nice. Whats funny is I think that this thing might be slightly physically larger than the LS1 motor!

People wherent' even hearing me when I alluded to a motor as a black box, that you dont care what it does inside as long as its light and makes power.

To make the ohc vs ohv that displacement is displacement, well OK what about a technology that makes your motor as 4'x4'x4' box but it displace only 5 liters...

Those graphs I talked about are out there, its alot of work to dig up but not sure if I want to prove my point that bad, because you already know that the higher end numbers that I gave happen - not as often, and the lower end numbers are in the range of well built setups that are out there.

racer7088

Big-DEN,

Yes I have a lot of the swap people and one even is putting an LS1 into an M3. That sure makes some people mad!

Quick Carl

I just saw S.A.M.'s new website and under class projects they have more pics and the 902 HP dyno pull with the LS7 intake.
The long rod in this combination will add to it's longevity with less side load and improved accel/decelleration at TDC and BDC. This should also help the heads by having additional time at the end of each stroke for cylinder filling or emptying. Dialing in the optimum amount of overlap vs. pumping losses for a particular head is as always the trick.