INDY/RHS heads

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I plan to on my 408 project, Brian at IMM Engines in California has them for $1469 a set, set up for .620 lift. My buddy had them on his 408, car went 10.80's thru the mufflers in his street Duster, 4.10 rear, 28" tall tires, heads had no port work done.
 
I have them on the 410 Brian built for me and they make good power . Best head for the buck you will find .
 
here also, IMM Engines LA-X Heads on my 408 for two years now....i still like them! Good machine work and a clean casting. i´d buy them again.

Michael
 
best heads for the Buck!
Had them on both Engines. 340 Stock block and then on the 416.
i would buy them every time again!
 
MRL Performance, a sponsor here, has done a lot of work with them as well.

http://www.mrlperformance.com/

He didn't do them, but a while back when I swapped a set of those heads in place of OEM J heads, I picked up 2-3 tenths on the same 360 engine. Both were professionally prepped/blueprinted with original valve sizes, but no port work. (1.88/1.60 vs 1.92/1.625.) Chambers were about 2-3 cc smaller on the LA-X heads.
 
I bought them for my pump gas 408 from Brian Fully CNC ported Hoping to haul some
Axx with them. Big giant roller and Indy intake
 
The only down side there heavier than stock
 
I have heard nothing but great things about these heads but I have a question.

Wouldn't it be better if they were aluminum so in addition to the obvious weight
savings, you could run at least another point of compression?
 
Old Man Mopar said:
I have heard nothing but great things about these heads but I have a question.

Wouldn't it be better if they were aluminum so in addition to the obvious weight
savings, you could run at least another point of compression?
Click to expand...

In theory heck yeah ,however in my case I'm not allowed to have aftermarket Aluminum heads on my motor and still maintain my Collector plates and the cheap insurance that goes with them so these iron LA heads are the cats backside .
 
I'm thinking these bars boys are gonna rock. It's gonna be awhile before its back together
Heck it's not even apart. I wanna spray my 360 before I take the car apart
But I will revive this thread and post a tuned up result
 
cannucky said:
In theory heck yeah ,however in my case I'm not allowed to have aftermarket Aluminum heads on my motor and still maintain my Collector plates and the cheap insurance that goes with them so these iron LA heads are the cats backside .
Click to expand...


Have you gotten yours back together after the head gasket problem ??
 
Old Man Mopar said:
I have heard nothing but great things about these heads but I have a question.

Wouldn't it be better if they were aluminum so in addition to the obvious weight
savings, you could run at least another point of compression?
Click to expand...
Ditto on the reviews... We went with the Edelbrock Performer RPM heads for this exact reason..... lower head temps and added detonation resistance. The lighter weight of them plus an AL intake shaved a total of 70 pounds off the car's nose vs stock iron.

As for best bang for the buck...... you can get the Edelbrocks on sale frequently with the discounts from one of the box stores (whose name starts with A); 15% off for those heads is easy to do and more % off with the right sale. The E's should be looked over IMO; we did for ours and a few issues were corrected and the area below the valve seats worked with a steep angle for better low end flow... all to the tune of $95 extra. I assume the RHS heads come better but do not know.

The level of the valve and spring quality between the 2 is unknown to me. The E's come out of the box for .575" lift rated, so the RHS buys you some extra lift if that is what you need. Looks like either is an easy 400 HP setup for 340/360 c.i., with a modest cam and intake/exhaust, or more with other stuff.
 
Old Man Mopar said:
Wouldn't it be better if they were aluminum so in addition to the obvious weight
savings, you could run at least another point of compression?
Click to expand...


Remember that extra point is restoring the heat that the aluminum takes away. You're not getting more bang for it - just getting back to where an identical head made of iron would be.
Aluminum vs iron always always always comes down to value - meaning cost vs reward. If someone places a higher value on initial buy in cost than some of the benifts aluminum will never make sense. Personally, if better heads are needed, no way I'm paying to run iron.
 
moper said:
Remember that extra point is restoring the heat that the aluminum takes away. You're not getting more bang for it - just getting back to where an identical head made of iron would be.
Aluminum vs iron always always always comes down to value - meaning cost vs reward. If someone places a higher value on initial buy in cost than some of the benifts aluminum will never make sense. Personally, if better heads are needed, no way I'm paying to run iron.
Click to expand...

I seen an article a while back to see if that was true or not. The test was on a small block ford and the heads they used I forget which ones but apparently there identical except the aluminum ones come with smaller chambers to give the CR a 1 point bump over iron and the aluminum ones made more power. At least in that one case it did.
 
moper said:
Remember that extra point is restoring the heat that the aluminum takes away. You're not getting more bang for it - just getting back to where an identical head made of iron would be.
Click to expand...
Seriously not trying to start any argument, but that simply is not making sense.... not sure it was stated as intended....?? The higher compression ratio indeed results in higher cylinder pressures and higher combustion temps, regardless of the head material, and thus more torque across all RPM's (as with any higher CR). The AL heads run cooler simply due to a thermal conductivity that is 3-4 times better than cast iron up at engine operating temps, not due to any difference in the the combustion temps by themselves.

You MIGHT, and I mean MIGHT, see a teenie-tiny increase of combusted gas temps and pressures with iron due to more preheating of the A/F mixture, but that effect is pretty marginal if at all. It is offset to some degree by less cylinder filling with a hotter A/F mixture. (How much does lower mixture heating with AL heads (and AL intake, especially an air gap type) allows better cylinder filling? I can't give any numbers.....) The effect of more mixture heating that we pay attention to is simply to increase the probability of detonation. The AL heads simply allow for higher CR because they themselves maintain lower surface temps, plus the mixture is indeed heated a bit less with AL, and those both lower the probability of detonation.

This is all related to the basis for modern gasoline direct fuel injection into the cylinders. Those engines can run 10-12:1 SCR all day long and make more torque and HP without detonation, because the fuel is injected directly into the cylinders after the compression starts, and thus the fuel has less time to absorb heat and thus less chance to detonate. It is all about cooler mixture, less detonation, and extracting more combustion energy with higher CR..
 
moper said:
Personally, if better heads are needed, no way I'm paying to run iron.
Click to expand...

You got that right after running Edelbrocks on 2 different motors i'll never waste my time with iron heads..except if they're W-2'S of coarse:D:D
 
"Seriously not trying to start any argument, but that simply is not making sense.... not sure it was stated as intended....?? The higher compression ratio indeed results in higher cylinder pressures and higher combustion temps, regardless of the head material, and thus more torque across all RPM's (as with any higher CR). The AL heads run cooler simply due to a thermal conductivity that is 3-4 times better than cast iron up at engine operating temps, not due to any difference in the the combustion temps by themselves."

Any heat lost to the cooling system is lost power. That's why thermal barrier coatings are all the rage (and coated chambers). I would agree the effect is probably not going to "1 to 1", but the reason one can run more compression is because more of the heat is being wicked away. If you can find me two heads identical in every way but the material I'd be interested in seeing the results. I said identical heads for that reason. No arguement here. It's scientific fact and thus far I haven't seen it seriously challenged because there are no complete apples to apples comparison. Whether someone buys into it or not makes no difference to me.
 
The question revolves around how much heat is wicked away from the actual instantaneous combustion temps. If those are not lowered around the peak, then there is little to no real torque or power loss.....in thermo terms, the PV curves does not change, where it counts. And if the loss is late in the cycle, when instantaneous pressure are way down, the effect ought to be minor. The head material an get the average heat away faster and thus lower the head surface temps, and raise the cooling system temps. But that does not automatically mean the actual combustion temps drop and pressures in any significant way. Perhaps a good way to figure this would be to measure exhaust temps.....that would be interesting.

Coated chambers...... damn you..... Now I need to learn more stuph! LOL Tnx for the discussion and the simulation to think. The education continues....
 
How these work is totally dependent on where you buy them. Some vendors use much better parts when assembling. Even with the head castings being the same, the end product is not apples to apples.

To get eddy's where they perform like a good rhs 2.02 would cost in the 2400-2500 range is my guess. A lot of cash to save 30#... :)
 
moper said:
Any heat lost to the cooling system is lost power. That's why thermal barrier coatings are all the rage (and coated chambers). I would agree the effect is probably not going to "1 to 1", but the reason one can run more compression is because more of the heat is being wicked away. If you can find me two heads identical in every way but the material I'd be interested in seeing the results. I said identical heads for that reason. No arguement here. It's scientific fact and thus far I haven't seen it seriously challenged because there are no complete apples to apples comparison. Whether someone buys into it or not makes no difference to me.
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I think carbon works as a great thermal barrier coating and it's free lol... i guess if you have a special race engine that somehow doesn't build up any carbon you'd see an increase in HP, but it does happen over enough time.
 
o1heavy said:
Have you gotten yours back together after the head gasket problem ??
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Oh yeah they were on the road in a couple of days and have been cross country twice since lol , funny you ask tho cause it's coming apart for a refresh as in rings bearings and some more cam , maybe the fitech EFI setup as well if I can make enough off all the trim parts I stripped off my 77 Grand Prix before it went to the great beyond .
 
yours is a real driver , that's pretty cool to see someone doing that with a 408
mine is gonnabe driven but mostly play at the track with my cheebee buddies
prolly run a season then dissemble and upgrade the heads
what was the head gasket problem ??
 
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