DURTYBIRD

OK, I just wanted to bounce this off some of you folks.

I met a gentleman today and I am wanting to find out if he's blowing smoke, or I have a line on an excellent deal.

He claims to have gotten an engine from someone else in exchange for some money he was owed.

He claims it is a 402ci "Lunati-built" SBC engine. He says the cr is about 12.5:1, aluminum heads, forged bottom end, etc. He claims it is rated at over 450hp and is still in the crate it came in. Its a long-block assy, all it needs is an intake and carb to run. He claims it was a $6k motor, and he would take $2k for it ($1k down and $100/month payments for 10 mos).

Is he just yanking my chain?

DURTYBIRD

Did a search for Lunati-built motors and came up with the following:


*Carburated motors:
*408 Cubic Inches:
*Lunati 408, from Car Craft March 1997
*Four bolt main 400, .040 over
*Lunati Pro Series 4340 crank, 3.75" stroke
*Lunati 4340 Pro Mod 6" rods
*Lunati and Taylor forged pistons, 13.3 compression
*Lunati solid roller cam, 282/292 @ .050, .734/.666 lift, 109deg lobe sep, 1.6 intake roller rockers, 1.5 exhaust roller rockers
*Brodix Track I heads, 69cc chamber, mild porting/blending, 2.08/1.60 valves
*Weiand Team G intake, Dyno-Tech 850 cfm Holley carb


RPM TQ HP
4500 453 388
4750 442 400
5000 474 451
5250 498 498
5500 515 539
5750 511 559
6000 495 566
6250 479 571
6500 472 584
6750 460 591
7000 436 582

RB83L69

Joe Lunati's company has been building motors for people for 3 decades that I know of. They cranked out alot of them from over there at one time.

It's pretty easy to build a 450 HP 400.

Find out if it was in fact built by Lunati, or since he sold his company to Holley, he's now in business with Bill Taylor who sold TCI to somebody a long time ago, and maybe it's that company. If it's really a Lunati motor, it's a good piece. Find out what heads are on it and what pistons are in it and stuff like that. Just because it puts out alot of power, soesn't mean that it will work well in your car.

But if it's suitable for you, then that's a good deal.

DURTYBIRD

I certainly will look at it before any money changes hands. Hopefully he's got some paperwork on it so I can tell for sure. He did say aluminum heads, so I can spot that easily.

If it is 12.5:1, if I run it with a carb in my '73 camaro, would that require race gas constantly, or could it be run on supreme unleaded. Aluminum heads shold give me a higher 'ceiling' that I can run supreme, right?

RB83L69

12½:1 is out of the realm of reasonable for any kind of pump gas.

I don't think it would be safe to go much past 11:1 with any kind of heads, on pump gas.

IMHO if it's really 12½:1, it's not suitable as a street motor, with any induction and wrapped in any sheet metal.

87WS6

iTrader: (1)

I would be interested in aquiring it for that price. Street legal or not. I'm in Texas. So I can pick it up. I'd want to verify the engine specs. That is if you are not going to do it.

jimmy_mac

Keep in mind that is probably a static compression ratio. If it is running a cam like the one you found in your search. with 282 deg at .050 and a 109deg log seperation then the dynamic compression will be way down. But then again if it has a cam that large you will need to fill up every 10 miles anyway.

But seriously if it has a big duration and skinny seperation that compression ratio won't be as bad as it looks.

RB83L69

I don't know where this myth about big cams allowing otherwise unusable CRs got started up again.... I thought that got dispelled by way of hard experience over all these years since the lead went away from gasoline, now here it is showing back up again.... in whatever RPM range the cam's properties result in max cylinder fill, it's going to be the same problem as it ever was, and will result in detonation.

A 450 HP 400 will most likely have a cam with 230° @ .050" intake duration. Which is pretty mild for a 400. I know, I have a 400 with a cam like that (Comp XR282HR). I have to be real careful what gas I run and where I set the timing, and I have 10.4:1 or thereabouts with iron heads. Aluminum heads aren't going to allow for 2 full points more of CR.... ½ point yes, 1 point maybe, 2 points no way.

It's too much CR for a street motor on pump gas. Believe it. With aluminum heads, you would be pushing it with any streetable cam at all on any pump gas. 12½:1 is completely unusable on the street.

More "real world" and less Desktop Dyno buzzwords would be useful in this situation.

DURTYBIRD

Not to second guess you or anything, as I certainly appreciate all feedback, but I did read a post over on the impalassforum.com about a guy running for years at 12.5:1 on premium gas from high-end gas stations like exxon, etc. Apparently the motor wouldn't run on gas (even premuim) from the more generic gas stations.

If it matters, the design of the '73 Camaro is to be a mostly weekend/track car in cooler months. It will not have A/C so I don't think that running around with it in the 100* summer months would be any fun.

RB83L69

Well it sounds like you want to do it whether it makes sense or not, so I guess it's OK, it's your money. I know for myself, I wouldn't even bother attempting to run that on pump gas. Too much BTDT.

Good luck!!

DURTYBIRD

Quite on the contrary. I'm still researching. This guy sounded like he's had the motor or awhile so I doubt that it's going anywhere. I don't even know how accurate his info is (could be 13.5:1 or 11.5:1 or ???) Could actually be a GMPP engine, etc... If anything I could always buy it and resell it...

jimmy_mac

You see the key word there is streetable cam. I have no idea what cam he is running. But anyway you are telling me that the little bit of time at the bottom of the intake stroke when the intake valve is hanging open as the power stroke begins doesn't reduce compression a little bit in a motor with a larger duration cam?

Oh yeah, I don't have a desktop dyno. And I ain't sophisticated enough to use buzzwords like folks on the west coast do.

AJ_92RS

Uh..... I'm kinda confused.

Is it a 402 or a 408?

You say in your first post that it's a 402, yet later you show the specs for a 408. What gives?

A 402 is a big block. It was sold as a 396 big block, but with a 4.126" bore instead of the 4.094 (both with a 3.76" stroke). For some reason GM didn't advertise it as a 402.

I'd try to check into it further. If it really is a 402, some old coot that restores muscle cars would give his left (you know what) for it.

Just do some thorough checking first. It may be a 400 SB bored .040" over, which is actually a 409, but not called that otherwise it may be confused with a REAL 409 and REALLY **** someone off.

Even if it is a 408 and has "non-stock" heads, I'd jump on it like it was Cindy Crawford.

DURTYBIRD

He said 402. I dunno how accurate that is and when I did a search, that's the 408 was the closest webpage with any specs that came up for an engine that was built by Lunati. If it IS a big block and has aluminum heads like he says it does, then fo' sho' I'll be all over that like stink on s**t!!!

More details to come! :lala: