djcwardog

Some of you have been following several threads I put up as I make decisions on an engine rebuild for when I get home this summer. I like the Voodoo Cams (shorter duration end of their line) and am looking for solid torque down low - never to rev over 5700 or so... Thinking oval ports are it for me. Likely to stay with stock cast-iron manifold or a '68-'69 427 390 HP al manifold if I can find one - all so I can keep using the stock hood. Will use 1 7/8" Hooker Super Comp headers.

I am considering doing a compression check and possibly just doing the top end first and driving for awhile before rebuilding with new pistons. I like the Edelbrock Al heads and also the GMPP heads. In fact, the 110 cc models seem almost the same. I want to get at least 9.5:1 CR and may consider going as high as 10.5:1 by virtue of having Al heads which are said to allow an additional point of CR before detonation occurs. My stock pistons are basically flat tops with valve reliefs. I get 8.25:1 CR with my '049 stock heads (119 cc). If I use and refresh my stock heads (or buy Al heads with 118 cc chambers), then I will need to skip straight to a rebuild using small-dome pistons to get to my desired CR. Gets a little better if I go with 110 cc heads (offered by both Edelbrock and GMPP) as I get around 9:1 CR with flat tops. Really interesting is Edelbrock's #6049 100 cc "TBI" head. These are basically closed chamber heads. That would give me a good CR (maybe up to 10:1 depending on head gasket choice) with flat top pistons - which are said to be better than domed pistons when one is worried about quench and detonation avoidance.

Does anyone run these Edelbrock 100 cc heads? Do they flow like their 110 cc (6045) brethren? Anybody have 28" flow numbers for them?

By the way, SDPC also sells GMPP L29 cast iron 99 cc small valve vortec heads. I wonder if they would flow well with 2.19/1.88 valves installed...? Of course, being cast iron they would likely give me too much CR and they may not work with my other planned components due to being Vortec? Comments on any of these (or other) heads or just in general? Please look up my other posts and see sig if questions about my setup.

Thanks!

73 LS-4

hey djc,

As far as I have learned with reading a few of my BBC books, the open chamber heads are the way to go, I've been considering the Performer RPM oval ports for a long time now and I think they will fit my bill giving me a little over 9:1 compression. Check through the threads somebody was looking at swapping an aluminum L-36 for something else not too long ago. I also saw a set of 049 heads for sale in the parts section, as another option you could have those heads reworked with bigger valves and shaved in order to bring the compression up, don't forget the intake will have to be shaved to match afterwords though. The 049's are one of the better flowing large oval heads, so given your not going to very high rpm's a warmed over set may fit the bill, of course you don't have the weight savings you would with the aluminum.


Pat Kunz

micks69

Wait untill summit has a 10% off day and go for the Performer RPM oval port heads I've got them on my LS4 and they really wake up the motor!

Jughead

I think Edelbrock makes the aluminum heads for GMPP. I'd still get the GMPP aluminum heads only I'd get the 100cc size this time. Weren't available when I bought my 110cc. At the time, I wanted GM parts. My choices were 118cc and 110cc. The 110 cc were the best flowing in their classs (290 intake) according to CHP magazine...even beat Edelbrock...

I wanted a complete "assembled head" and not something requiring purchasing valves, spring & retainers. I thought they were the best bang for my buck.

Shop around for prices. Salleee Chevy had the best price at the time and cost only $47 to ship from the left coast.

Les

I went w/ the Edelbrock 100cc heads because my bottom end was fresh & I'd built the motor to 9.5 to 1 w/ the stock closed chamber heads. I wasn't willing to lose any compression, especially since i was stepping up quite a bit w/ my cam choice. The flow numbers are supposed to be the same for the Edelbrocks in both chamber sizes.

In your case I think you need to decide on a cam first because that will affect your cylinder pressure & therefore what chamber size would work best for you. Good flow won't do you much good if your motor is lazy due to low cylinder pressure.

The heads I have work very well w/ my cam. Since I changed them both at the same time I can't tell you how much difference each made but together they changed the personality of the motor- in a good way.

GDaina

Where's the left coast?


Also try www.Paceparts.com Len...you could have driven to Girard, Ohio and picked up the heads.

ImBatman

djcwardog


I did alot of comparisons before I bought my heads and it came down to the Edelbrocks and the GMPP heads that Jughead went with. I don't think you can go wrong with either head. I did talk to edelbrock tech about the valve size and they recommended the smaller 2.19' vice the 2.25 for my application. My target rpm range is 6500 and under and based on my cam and intake choice the 2.19 110cc were the better fit. The decision between the GMPP and the edels was purely the fact that I wanted to get everything from the same place. Flow #'s and price were all closely comparable.


Hope this helps.

djcwardog

Guys,

I was a bit confused by the product names on all the heads, so I went and read up some more. I am quoting Edelbrock's info and sticking with street head info. They do make a Victor, Jr. 112 cc race head with oval ports but it likely wants too much RPM before it starts to make power...

A new question - what does an exhaust cross over do? Is it needed for the EGR valve or is it the source of hot air under the carb that makes a stock divorced choke work?

Anyway the street (and two marine heads as well) data:

Performer RPM 454-O

Chamber Size Bare (single) Complete (single)
110cc #60449 #60459
Polished Performer RPM 454-O
Chamber Size Bare (single) Complete (single)
110cc N/A 604519

Designed for big-block Chevy 396-502 c.i.d. engines, these oval port heads will support over 540 hp with 9.5:1 compression when used as part of the Total Power Package. Our unique intake port design produces flow close to rectangular port heads, but with the smaller port size and velocity of an oval port for excellent seat-of-the-pants performance and crisp throttle response. The semi-open chamber design maximizes combustion efficiency with streetable compression ratios. The stainless steel 2.19" intake and 1.88" exhaust valves have smaller-than-stock 11/32" valve stems to promote excellent flow and lighter valve weight. The deck surface and water jackets were specially designed to work with all big-block Chevrolet engine blocks. Heads include top-quality ARP rocker studs, bronze guides and hardened, ductile iron valve seats. See chart for more specs.

Street legal Performer 454-O
Chamber Size Bare (single) Complete (single)
110cc #60469 #60479

Performer 454-O cylinder heads have the same outstanding features as the Performer RPM heads but with an exhaust crossover passage for a 50-state emissions legal status. Match these powerful heads with our Performer manifold, Performer-Plus cam and an Edelbrock square-bore or spread-bore carburetor for a Power Package that’s capable of over 470 ft/lbs. of torque at 3500 rpm. See chart for more specs.


Performer High-Compression 454-O
Chamber Size Bare (single) Complete (single)
100cc #60489 #60499

Designed for 396, 427 & 454 (7.4L) c.i.d. engines, these 100cc semi-open chamber heads feature a 1-1/2° rolled over (angle milled) design that improves intake port alignment and provides a smaller combustion chamber without shrouding the valves. The 100cc combustion chambers are coupled with the same size valves and ports as the #60459 Performer RPM heads, producing 9.2:1 compression with flat-top pistons for an outstanding high performance street head. When used on 1987-up TBI equipped 7.4L dished piston motors they produce an 8.8:1 compression ratio and made over 450 ft/lbs. torque when combined with our Multi-Point EFI System. The heads also feature an exhaust crossover passage for 50-state emission legal status. Available assembled with high quality components: one piece stainless steel, 2.19" intake and 1.88" exhaust valves: ARP 7/16" diameter rocker studs, bronze guides and ductile iron seats with 3-angle valve job. Features stock port locations, 9/16" deck thickness and heli-coils in the rocker stud and exhaust bolt holes. Mark IV rocker arms and valvetrain parts required. See chart for more specs.


Performer RPM 454-R (These are rectangular port heads)
Chamber Size Bare (single) Complete (single)
118cc #60549 #60559
Polished Performer RPM 454-R
Chamber Size Bare (single) Complete (single)
118cc N/A #605519

Performer RPM rectangular-port heads have specially designed intake and exhaust ports for increased flow and velocity over standard big-block heads. These heads feature a highly-efficient 118cc open-style combustion chamber and high-velocity 315cc long/300cc short intake ports. Designed for street/high-performance big-blocks operating from 2500-7000 rpm. Stainless steel, hardened tip 2.19" intake/1.88" exhaust valves have 11/32" valve stems for excellent flow and lighter weight. The deck surface and water jackets work with all generations of big-block Chevy blocks. Heads include top-quality ARP rocker studs, bronze guides and hardened, ductile iron valve seats. See chart for more specs.


Note: The spark plug has been moved closer to the center of the bore and will interfere with high-dome pistons designed for stock Chevy open chamber heads. Use high-dome pistons designed for these heads.

Important Notes:
Please use Head Bolt Kit #8551 for an easy installation.


Marine-Duty Performer RPM 454-O and 454-R
Performer RPM 454-O Marine oval port
Chamber Size Bare (single) Complete (single)
110cc N/A #61459*
Performer RPM 454-R Marine Rectangular port
118cc N/A #61559*

Designed for 396-502 c.i.d. big-block Chevy engines, these heads include heavy-duty, 1.89" Inconel exhaust valves that provide the added durability needed for marine applications and have one-piece stainless steel 2.25" intake valves with hardened tips and swirl-polished heads. The high-velocity flow capabilities of Edelbrock Performer RPM cylinder heads provide increased torque across a wide rpm range that’s ideal for marine use. Cast from A356 aluminum and heat-treated to T6 specs. The oval-port heads have 110cc chambers and the rectangular port heads have 118cc chambers. Both the oval and rectangular port heads are hard anodized to protect the aluminum in the harsh marine environment. Edelbrock big-block Chevy marine heads are sold with seals and valves only for a variety of combinations. Match with an Edelbrock Performer RPM manifold, Performer Series 750 cfm or 800 cfm carb and Performer RPM cam for proven performance.

ImBatman

I have the 459's. No cross over. I am not quite sure what it is for so some others can probably shed more light on this than me but with my combination it was not needed. I would think that you would not either.

Wade

Steve's74

The exhaust crossover was originally intended to provide a source of heat in the intake manifold to improve fuel vaporization on cold engines. In later years with EGR, this passage was also utilized to provide the supply of recirculated exhaust. Since maximum power is usually achieved via a colder air/fuel mix, race engines eliminate the crossover. On a street engine, many people "block off' the crossover to prevent heating of the intake. The "heat riser valve" in the exhaust mainifold is spring loaded (and/or vacuum operated) to force exhaust into the crossover when an engine is cold. The crossover also provides heat for the divorced style auto chokes to warm up.

If you can tolerate a little cold hesitation, stumble and bog you do not need the crossover. Having said that, in emmission inspection states, you may be required to have the crossover.

Steve

djcwardog

Looks like the #60499 100cc heads only come with the crossover. I like the idea of keeping my divorced choke and I can choose a different manifold ('68 or '69 aluminum L36?) that has no EGR, so I get the best setup. That said, looks like it boils down to the Edelbrock #60499 100cc or the #60479 110cc versions. I agree that 2.19" valves are all I need with a non-race 454. If I were running a 502 I would want the 2.25" valves. By the way, Edelbrock's web site says that the 100cc heads deliver 9.2:1 CR with flat top pistons... Maybe a very small dome is needed to get a bit higher... TRW 2399 pistons (aren't these in your engine Jughead)?

LemansBlue68

I recently got a flyer from Summit that listed these marine heads at $1450 for the pair. These are better heads than the street version (because of the better valves) and cheaper too! I just wish I had the cash at the moment to afford them myself. Only draw back is the 100cc version isn't available as far as I know, but you can always ask.

Another outfit that has some outstanding prices on aluminum heads is Competition products in Oshkosh, WI. They have quite a variety and very good service reps.

djcwardog

$1450 a pair is a good deal at Summit. Of course, seeing the recent thread with the LS-7 motor (20 years on a crate) and the going auction price just reminds me how much I will spend to modify/rebuild the stock motor... With that LS-7, I could just swap out pistons and run a hydraulic cam and have a streetable piece of history - easily convertible back... Of course, forget the low rpm play with that one - revs to the max! At what point will I just say OK and buy a second (crate...ZZ454?) motor that has the features I want and put the original motor in the corner of the garage? It's like building your own PC from parts. Years ago, you saved lots of money and had a great computer. Now they're all so cheap that a home-built costs more! Same with these awesome big blocks!

Jughead

They're '71 LS-6 replacements. They have a smaller dome height than the original LS-6's 13.8cc I think.

GDaina

Matching piston to head ( open to open, closed to closed chamber, one exception, closed piston to open chamber is ok) is engine building 101..will make your head swirl how many make the wrong choice and upon startup wonder why the motor granaded.

djcwardog

Jughead,

Those TRW-L2399F30 forged pistons with a piston dome volume of 13.80 cc are definitely on my list to consider. However, they are $50.95 each at Summit! Playing around with DD2000 using bore 4.280" (0.030 overbore), gasket bore diameter/thickness (a Fel-Pro gasket for Al hds) = 4.370"/0.039", and a deck clearance of 0.020" (what they recommend on Summit's search results), I get a calculated static CR of 9.53 using 110 cc heads. Used with my stock 119 cc CI heads, the CR would only get to 8.92 - but that's better than my current 8.25 stock CR! If I use the Edelbrock 100 cc Al heads, I come up with 10.38 CR. Jughead, If you feel you can push CR that far on pump gas (and with a long duration cam I'll bet you can...), you may want to do another head swap!

Summit also sells two Keith Black Hypereutectic pistons that look good on paper. Their UEM-KB257030-8 has a dome volume of 25.50", and is noted for use on open chamber heads only. A set of 8 runs $293.39 at Summit. Using my stock cast iron (CI) '049 open chamber heads of 119 cc, I get CR = 9.68. The head gasket is just a bit different for cast iron heads (4.340" gasket bore diameter and 0.038" compressed thickness). If I rebuilt to this spec with these pistons and decided later to add aluminum heads, then the 110 cc Al heads and appropriate gasket would yield 10.43 CR. As a joke, the 100 cc Al head CR is a whopping 11.48 - if you could call such a head open chamber - engine grenade is more likely the case here!

Keith Black UEM-KB203030-8 are also hypereutectic, with a dome volume of 12.00 cc - just a tad less than the TRW-L2399F30 pistons above. 119 cc CI Cr is 8.72, and it goes up to 9.31 with the 110 cc Al heads. 100 cc Al heads go up more - to 10.11.

As my domes have to be within a range of ~10 to 26 cc for the CR's to work out, Summit only offered one Speed Pro (TRW) hypereutectic piston that I could find. It is STL-H426CP30 ($26.69 each) with a dome volume of 10.50 cc. 119 CI cc CR is 8.63, 110 Al CR is 9.20, and 100 cc Al CR is 9.98.

However, Summit does offer another forged TRW piston worthy of consideration, the TRW-L2465F30 at $39.95 each. With a dome volume of 25.70", the 119 cc CR is 9.70, the 110 cc CR is 10.45, and the 100 cc CR is 11.50. This is the one for hardcore users - I think a hypereutectic with its inherent tighter sider clearances suits my plans better...

There are some open chamber domed pistons of 29 cc and more, but CR is too high with these. I like the idea of picking a piston for the stock '049 heads and then being able to just do a head swap if I want more juice later.

I ran all the numbers above at recommended deck heights of 0.020" or 0.025" as each piston called for. If you run a zero deck clearance, these CR numbers will definitely go up - especially as head chamber volume goes down!

By the way - the poll shows the 110 cc heads in a clear lead. I just got flow specs on the L29 Vortec heads and ran them on DD2000. Result - they're dogs in that they flow appreciably less than my stock '049 heads and cut power on DD2000. So, forget them for my application but they're probably great on a tow rig.

Gage

I am going to run the 049 heads with the TRW2349 pistons. Should be around 10:1 comp. Just right

BB wowbagger

I`m using the #781 heads

djcwardog

Gage,

I ran the numbers on those heads but thought the CR just a bit high for the cast iron '049 with my range of cam choices (shorter duration and high lift). The TRW-L2349F30 pistons ($48.95 each at Summit) gave me these numbers on DD2000: 119 cc CI Hd yields 10.11 CR, 110 cc Al hd yields 10.94 CR, and 100 cc Al hd yields 12.11 CR. Summit reports that the CR for 119 cc CR is approximately 10.01. Are you running a 0.030 overbore? I guessed that I would end up there. If not, the numbers change only a little - no biggie.

Super Stock

Another alm. head that's worth a look is the Brodix racerite .