360 4bbl Performance

[wyrmrider]

just pulled up the Lill red express specs 78 detuned in 79 355 9 1/4 rear end rear end 8.2 compression windage tray no serial number on rt side of block
no cats 850TQ PD intake manifold 252-252 mopar degree cam overlap mopar 33 degrees (compare with other mopar cams)
68 340 cam regular spec is near 276 .484 lift and 48 degrees overlap from one source but I don;t think so red stripe valve springs no rotators
another source says 268-276-44 cam
Engine code EH-1 225 net hp @3800 this was a sandbag cus it put out more than that at higher revs 295 ft lbs at 3200
hemi mufflers with crossover 2 1/2 inch pipes
1.88x 1.62 valves mopar wicki says forged crank- Ive never seen one
wiccki says 440 valve body and 9" 2500 stall converter- never seen one of those either - anyone else?
IMHO "super heads" refers to the W2 on the prototype- I've only seen standard production "selected crankshaft"
340 cam, 3:55 gears and a looser converter would almost work in an 8.2 compression motor
HRN says 8.4 cr wheras E58 was 8.0 74 360 piston PN 3780071 someone can check the spec

 

[rumblefish360]

The LRT’s 360;

The “Super Heads” is a new one to me.
The W2’s never made the production line as OE vehicle heads. Dam shame.
1.88-1.60 valves. Not 1.62.
Never seen or heard of a factory 9 inch converter, just “Factory High Stall.”
Stock HP 340 cam.
I also don’t know what a 440 valve body has over a 360 valve body for the same transmission.
Unsure of the compression ratio differences. None that I’m aware of. It doesn’t make sense to have a small short run of special pistons just for one low selling vehicle in the line, nevermind corporate wide.

 

[wyrmrider]

I thought that one website had a lot of baloney information
I think if I x-referenced that piston number it would be the same
440 hp valve bodies are different but nothing a shift kit can't fix _ IDK about 360 HP 727 valve bodies- they are all just cores to me
so it looks like to sharp guys Hoover and Koffel made about the best 360 they could (agree about the W2's)
I still think low compression 360's die with tall gears and a standard converter especially if you stick a 280 cam in one-even a fast acting 270
I'm thinking the converter they used must have been the 340HP one- nothing special

 

[rumblefish360]

so it looks like to sharp guys Hoover and Koffel made about the best 360 they could (agree about the W2's)
I still think low compression 360's die with tall gears and a standard converter especially if you stick a 280 cam in one-even a fast acting 270
I'm thinking the converter they used must have been the 340HP one- nothing special

Agreed. Regular Stock engines are low in the comp. ratio and just simply do not respond well to cams above 220/224-ish area. With no real back up beyond it. The converter and rear gears need to be addressed along with it. Nevermind what the rest of the engine could lack or bennifit from.

I’ll still say it, fast rate ramp cams are:

1: Over rated

2: Not really aggressive enough in most cases to take advantage of the .904 lifter.

3: some are just make a lot of calve train noise and/or wreck valve trains from imperfect installations/match is components.

Installing race cams in stock engines spells problems. Heck, half a race cam causes problems.

 

[wyrmrider]

Most are not really fast rate cams
they are standard rate cams that start farther from the center of the lifter so you have ore "leverage" without any faster ramp
using a fast rate chevy master on a mopar is a wear problem the mopar valvetrain (without mega $$$) is much heavier than a SBC even BBC is a little lighter than a BBM
agree about race cams on the street
back in the day of the stock size lifter rule we used to offset the bushing where you could run a FORD profile on Chevy lobe -opening on the bigger offset side
problem was they started to do fords special for the larger base circle which is a problem when you go smaller There was a lot of development for FORD size for NASCAR etc
Cranes BBM .904 grinds are pretty mild but smooth but still better than chevy

 

[rlem1977]

I've seen two HP/Torque ratings listed for a '74 360 w/ 4bbl on a couple of websites/sources now:

V8-360 4-bbl; 4.00 x 3.58; 8.4:1; HP: 200 @ 4000 Tq: 290 @ 3200 45-65
V8-360 4-bbl; 4.00 x 3.58; 8.4:1; HP: 245 @ 4800 Tq: 320 @ 3600 45-65

What is the difference in these two setups that gives one more HP/Torque? (Or is this the same engine setup measured at different RPM? Seems like a big difference though). If there is a difference, how would I be able to tell the difference if I were looking under the hood in a vehicle?

Thanks

From what I have read, the 360 debuted in 1971 and replaced the 383 as the optional engine in the Polara, Fury, and Newport. In 1974, a new version was made that had a 4-barrel = 200hp/290 ft. lbs. Since Chrysler had killed the 340, in 1974 they swapped some of the 340 performance parts into the 360 including a 4-barrel carb and cam to get performance back to 245hp/320 ft. lbs. for cars like the Challenger, 'Cuda, etc. There may be other versions of the 360, too. Hope this helps.

 

[Zell]

From what I have read, the 360 debuted in 1971 and replaced the 383 as the optional engine in the Polara, Fury, and Newport. In 1974, a new version was made that had a 4-barrel = 200hp/290 ft. lbs. Since Chrysler had killed the 340, in 1974 they swapped some of the 340 performance parts into the 360 including a 4-barrel carb and cam to get performance back to 245hp/320 ft. lbs. for cars like the Challenger, 'Cuda, etc. There may be other versions of the 360, too. Hope this helps.

Thanks, rlem1977. Did your sources mention if it was just the Late model cars that had the cam/carb from the 340, some out of certain plants, or anything specific?

 

[rumblefish360]

The hp 360’s can be found in many vehicles but it had to be ordered or legal. You would be looking for the engine code E58.

 

[Zell]

Thanks, rumblefish360. From your name alone I have to ask if you are running a hp 360?

 

[rumblefish360]

4 of them.

 

[Zell]

4 of them.

!! I've heard they are popular motors. Where do you find this kind of stuff? Keep checking Craigslist, Mopar meets, this forum?

I've never had the chance to work on a LA360, only the Magnum 360 in a Dodge RAM that 1500. But even still I had a good experience with that motor. I liked it very much.

 

[rumblefish360]

Well the older 360’s are generally the same. Just not roller cam equipped and the block has oil passages that go up to the heads. That’s the biggies.

I’d be lucky to find a car with a LA 360 in it now since those cars are now old and junked. The junk yards use them for there scrap weight.

Now, I’ll look for another cheap ride with a 5.2 or 5.9. Pirate what I can used and scrap the rest. The Magnum engines are a little nicer in the block area except no head oiling. And that creates a small problem. But the blocks are newer, machined better and are a little beefier.

I don’t know how California is for there junk yards. But I’d start there with the lowest mileage engine I can find.

Swap meets and forums are OK. But you have to have cash ready to spend when you find them.

Another good source are the car clubs. While you may not have to join, the idea of net working comes in. This forum (and FABO) has brought out a number of Mopar guys I probably would not have met. The forums make it easier and more friendly for meetings.

 

[kiwigtx]

2 cams were used. The basic broom stick 2bbl cam and the 4bbl. cam which is the 340 cam.

A broom stick cam gives a real smooth idle.

 

[rlem1977]

Thanks, rlem1977. Did your sources mention if it was just the Late model cars that had the cam/carb from the 340, some out of certain plants, or anything specific?

Power decreased gradually from 1974. The LA-series 360 in cars ended around 1980. They continued on in trucks, van, and SUVs. In 1993 the 5.9 Magnum version appeared with better heads, intake, and fuel injection - improving performance to around 230hp. Still available in trucks, vans, SUVs and cop cars. Production of the LA-series engines ended at the end of 2002.

 

[YY1]

My 73 Duster had a 76 360 built to stock 360 Mag specs including the cam.

It ran great with a 904, stock converter, 3.23 SG, manifolds with dual exhaust and an iron intake with a 600 cfm AFB.

Easy "full rotation" style chirp into second just letting it shift.

I believe I remember it running 8.90 at 93 in the 1/8 mile

Agree 360 and 400 have an undeserved bad rep, IMO mostly because of the widespread misunderstanding of the HP rating change from gross to net.

 

[Dako]

I was thinking that the high performance 360 engines in the 70's were built for the trucks like The Little Red Express.

HP went into Lil Red Express & Duster 360.

 

[rumblefish360]

I had a ‘78, 400 in a Duster. It was pretty crappy. But dead reliable.

 

[YY1]

I also had a 2 barrel 77 400 out of a van, in my 70 Super Bee for a little while.

That motor ran like a scalded dog. I was afraid to F with it it ran so good.

 

[wyrmrider]

remember what gears and converter in your superbee YY1?

 

[YY1]

stock converter, fresh 727 with "green waffle" clutches and factory 3.55 SG

also Hooker super comps and full H pipe 2 1/2 exhaust

With it's "correct" 70 HP 383 9.5:1 motor, 284/484 MP cam, torker intake, and a hybrid 600/750 franken-Holley in place of the 400 it would hang tight and frequently win on the street with mid 13 second cars.

It was almost as good with that 400-2!