Edelbrock RPM aluminum heads for 360LA.. opinions

[Scooter]

Going to tack this onto the end of this thread. Since I saved a few hundred bucks on the heads by going with the PM's over the Eddy's.. I'm thinking of upgrading the rockers while I am at it. With the springs and flow numbers of the new heads I'm thinking of maybe using a 1.6 ratio rocker. The flat tappet cam currently installed has .450 intake and exhaust lift @110LS. If the online calculators are correct going from 1.5 to 1.6 will add about .030 for .480 total. Well within the .575 maximum of the springs the head ships with. Is there a downside I am not taking into consideration? Speeding up the the ramp, increasing the duration and valve lift all seem to say do it!

[7212Mopar]

Are you thinking roller rockers? They make 1.7 ratio too but most just go with 1.6. I was looking at the Hughes Engine setup but my builder put in the PRW SS to help save some $. Bad reviews on them on quality control if you Google. But those were older reviews. So far I don't have problem with them and some other members have them in their build as well.

[Scooter]

Are you thinking roller rockers? They make 1.7 ratio too but most just go with 1.6. I was looking at the Hughes Engine setup but my builder put in the PRW SS to help save some $. Bad reviews on them on quality control if you Google. But those were older reviews. So far I don't have problem with them and some other members have them in their build as well.

Quite possibly rollers if the $$$ is close enough. The Hughes are really nice... probably too nice for my lil low compression setup & pricey. Mancini makes a decent set and I've looked at the PRW SS. I'm looking at 1.6 to bump valve lift to .480 on both sides. I'm still under .500 so I don't think I'd run into valve to piston clearance issues. I'd have my machinist buddy who is going to give the heads a once over measure clearances to be sure. Would go back together initially with the stamped rockers.

[Chryco Psycho]

I don't see a downside to going with the 1.6 , you will not have a problem typically with hitting the piston with lift that low .
For similar $$ you could swap the cam & get a better result .

[Scooter]

I don't see a downside to going with the 1.6 , you will not have a problem typically with hitting the piston with lift that low .
For similar $$ you could swap the cam & get a better result .

Don't know if that thump stick comes out with the block in the car.... AC would be a pain to get out of the way. Then I'd need to get better rockers too boot.

I'm thinking the heads are coming out anyway.. why not get 1.6 & maybe a thinner head gasket to bump the compression a bit. What is a stock 75 360LA from the factory like 8.4CR?

Got at least 4 weeks till the heads arrive.. will be keeping my eyes open for a deal on rockers. 

[7212Mopar]

Compression will go up with the new close chamber heads. You can check valve clearance and with clay before torque down the heads. May be check the push rod length just in case.

[mopartaz]

Racer Brown cams:
http://4secondsflat.com/Racer_Brown_Cam_Specs.html

[gzig5]

Are you thinking roller rockers? They make 1.7 ratio too but most just go with 1.6. I was looking at the Hughes Engine setup but my builder put in the PRW SS to help save some $. Bad reviews on them on quality control if you Google. But those were older reviews. So far I don't have problem with them and some other members have them in their build as well.

Quite possibly rollers if the $$$ is close enough. The Hughes are really nice... probably too nice for my lil low compression setup & pricey. Mancini makes a decent set and I've looked at the PRW SS. I'm looking at 1.6 to bump valve lift to .480 on both sides. I'm still under .500 so I don't think I'd run into valve to piston clearance issues. I'd have my machinist buddy who is going to give the heads a once over measure clearances to be sure. Would go back together initially with the stamped rockers.

I have a set of the PRW 1.6 SS rockers for my PM heads.  Overall, the quality of the rockers is pretty good, but they need to be gone through and have the threads and holes cleaned up.  Mine had some machining debris in some of the passages.  The only down side is that like a lot of other aftermarket rockers on aftermarket heads, the rocker body interferes with the spring retainer on a few of the valves.  Easy fix is to just grind the rocker body for a little clearance. The interference comes from a couple sources, one being the cast body is hand finished, ie they are not all identical. The other is that these heads really need to have the rocker shaft shimmed to move up and away from the valves a bit to optimize the geometry of the longer valves and taller springs, and center the sweep of the roller on the valve tip.  The rockers fit fine on stock heads with stock valve lengths and stock diameter springs.  The only company to address rocker shaft location I am aware of is TF with their new effort and it is why they recommend certain rockers.  Not the end of the world but be aware of it.  This is fairly common with various aftermarket heads and rockers because they were not really engineered to work together and it's part of "hot rodding".  I haven't decided if I'll correct the geometry or just grind the clearance on mine.

Here is a good read on the details of it.  For a street motor that isn't revving much over 6k, geometry isn't going to kill the motor. If you have higher HP and RPM goals, it might be something to consider.  There are a lot of engines out there running just fine without shimming the rockers on aluminum heads. 
http://www.b3racingengines.com/techcorner.asp

[Chryco Psycho]

Yes the cam can be swapped out with the engine in the car , the condenser would have to be moved to allow enough room which usually can be done carefully without disconnecting the lines . Lunati VooDoo has a number of choices over .500 lift with tight duration for great street drivable use .
Yes closed chamber heads will raise the static compression but alum loses heat faster so you also lose approx 1 point of compression with heat loss .
You can check Cometic head gaskets , you can get any thickness made , almost ] & they work bets with Alum heads & the very different expansion rates between Alum & steel .

[DrEamer]

...... but alum loses heat faster so you also lose approx 1 point of compression with heat loss .
You can check Cometic head gaskets , you can get any thickness made , almost ] & they work bets with Alum heads & the very different expansion rates between Alum & steel .

I know I have seen you post this information on various forums, and heard this myself. Last year Engine Masters  on Motor Trend did an episode to test this and found no difference in aluminum and cast iron heads power wise. I found an older article from Hot Rod where they came up with the same conclusion which I'll link below. If nothing else, I would like you take on it.

https://www.hotrod.com/articles/ccrp-0602-iron-versus-aluminum-cylinder-heads-test/

[Scooter]

Compression will go up with the new close chamber heads. You can check valve clearance and with clay before torque down the heads. May be check the push rod length just in case.

Roger that, would like to see CR over 9. Still streetable on pump gas without detonation issues even with the crap gas we have here in CA.

Was playing with the Summit compression calculator last night. Just going from the 68cc to 65cc heads bumps the CR to 8.7. If I use a .027 Head gasket that kicks it up to 8.9. The unknown right now is the deck height, don't know exactly how far down the slugs are in the hole. The receipt the original owner provided only provides a check mark next to decked... no numbers. I'll have to wait till the heads are off to get the number so I'm going with stock on the CR calculator right now which info on the pistons on the receipt say should be about .111.

[Scooter]

Are you thinking roller rockers? They make 1.7 ratio too but most just go with 1.6. I was looking at the Hughes Engine setup but my builder put in the PRW SS to help save some $. Bad reviews on them on quality control if you Google. But those were older reviews. So far I don't have problem with them and some other members have them in their build as well.

Quite possibly rollers if the $$$ is close enough. The Hughes are really nice... probably too nice for my lil low compression setup & pricey. Mancini makes a decent set and I've looked at the PRW SS. I'm looking at 1.6 to bump valve lift to .480 on both sides. I'm still under .500 so I don't think I'd run into valve to piston clearance issues. I'd have my machinist buddy who is going to give the heads a once over measure clearances to be sure. Would go back together initially with the stamped rockers.

I have a set of the PRW 1.6 SS rockers for my PM heads.  Overall, the quality of the rockers is pretty good, but they need to be gone through and have the threads and holes cleaned up.  Mine had some machining debris in some of the passages.  The only down side is that like a lot of other aftermarket rockers on aftermarket heads, the rocker body interferes with the spring retainer on a few of the valves.  Easy fix is to just grind the rocker body for a little clearance. The interference comes from a couple sources, one being the cast body is hand finished, ie they are not all identical. The other is that these heads really need to have the rocker shaft shimmed to move up and away from the valves a bit to optimize the geometry of the longer valves and taller springs, and center the sweep of the roller on the valve tip.  The rockers fit fine on stock heads with stock valve lengths and stock diameter springs.  The only company to address rocker shaft location I am aware of is TF with their new effort and it is why they recommend certain rockers.  Not the end of the world but be aware of it.  This is fairly common with various aftermarket heads and rockers because they were not really engineered to work together and it's part of "hot rodding".  I haven't decided if I'll correct the geometry or just grind the clearance on mine.

Here is a good read on the details of it.  For a street motor that isn't revving much over 6k, geometry isn't going to kill the motor. If you have higher HP and RPM goals, it might be something to consider.  There are a lot of engines out there running just fine without shimming the rockers on aluminum heads. 
http://www.b3racingengines.com/techcorner.asp

^^ Funny.. I read that entire article just last night. Should not be a big issue on mine, 360 rarely gets spun up over 4k. Will be checking clearances and contact points as I go for sure no matter which rockers I go with.

[Scooter]

Yes the cam can be swapped out with the engine in the car , the condenser would have to be moved to allow enough room which usually can be done carefully without disconnecting the lines . Lunati VooDoo has a number of choices over .500 lift with tight duration for great street drivable use .
Yes closed chamber heads will raise the static compression but alum loses heat faster so you also lose approx 1 point of compression with heat loss .
You can check Cometic head gaskets , you can get any thickness made , almost ] & they work bets with Alum heads & the very different expansion rates between Alum & steel .

Plan right now is to roll with the cam that's in it. Replacing it in the car is just more than I want to take on this summer. 

[Chryco Psycho]

Here is my take , the piston stay at TDC a lot longer on a Mopar engine due to the long rods , a stroker chev smallblock is a completely different engine , how often does anyone really test on a Mopar engine for starters . The piston will run away from the head & combustion a lot faster on a Chev . Does this matter overall Maybe or maybe not , but with a piston that sits at TDC longer there is more complete combustion & as the piston moves away slower there is more time for the pressure to work against the piston , time may affect heat loss .
What it of most concern is quench so the piston at TDC needs to be under .060 away from the head , this will stop detonation as demonstrated at least partially in this test using almost 11:1 compression .
After I win the lottery I will buy my own dyno & do testing just like this all day long & learn constantly !

[Scooter]

Here is my take , the piston stay at TDC a lot longer on a Mopar engine due to the long rods , a stroker chev smallblock is a completely different engine , how often does anyone really test on a Mopar engine for starters . The piston will run away from the head & combustion a lot faster on a Chev . Does this matter overall Maybe or maybe not , but with a piston that sits at TDC longer there is more complete combustion & as the piston moves away slower there is more time for the pressure to work against the piston , time may affect heat loss .
What it of most concern is quench so the piston at TDC needs to be under .060 away from the head , this will stop detonation as demonstrated at least partially in this test using almost 11:1 compression .
After I win the lottery I will buy my own dyno & do testing just like this all day long & learn constantly !

^^^ LOL.. this. If I had a dyno & a good test mule you'd need explosives to get me off it.