Edelbrock Performer RPM (7577) and 360 Magnum CI heads

[MechEngr]

1998 magnum 360
stock rods & crankshaft
KB-107 pistons +.030
PIE stage 1 EQ heads
Comp Cam 20-746-9
*** Edelbrock Performer RPM Intake Manifold (7577) ***

I'm building this 360 magnum for my 1967 Barracuda and am questioning my choice of intake manifold and am hoping for some experience/guidance from the experts.

I have 2 concerns with intake manifold:
1 - The heads have coolant ports at both the front and back of the heads. The Edelbrock manifold only has coolant ports at the front of the manifold and my concern is lack of adequate cooling for the cylinder heads.
2 - There is a significant mismatch with the ports on the engine -vs- ports on the manifold.

It might be that this intake was only intended to be used with Edelbrock Performer RPM heads.

I guess I could modify the intake gasket to accommodate the Edelbrock mismatch, but even with that I think I would end up with slightly restricted flow due to the mismatch. My other option is just to look for another intake manifold that has the proper coolant ports.

Any sage advise out there?????

 

[MechEngr]

I just look at the kegger that came of the engine and it doesn't have coolant ports on the rear of the intake manifold. I wouldn't have expected this!

 

[Bobzilla]

Coolant ports are NOT an issue, normal as you saw comparing the kegger. It makes the heads able to go on either side of the engine and the intake blocks the rear ports that are not needed.

Can you post a picture showing all four ports at one time. Last picture looks like a problem but only if the ports not shown ARE lined up nicely while those shown are not.

 

[MechEngr]

The first photo is of the intake with the gasket lined up with the intake ports, and all intake ports were lined up correctly. The second photo is of the intake with the gasket lined up with the coolant port, and all the intake ports were offset. I will post additional photos.

 

[Bobzilla]

The first photo is of the intake with the gasket lined up with the intake ports, and all intake ports were lined up correctly. The second photo is of the intake with the gasket lined up with the coolant port, and all the intake ports were offset. I will post additional photos.

Got it. Do not worry about the coolant port being a little off, as long as it has plenty of gasket coverage to seal the coolant port. Make sure the intake ports are lined up, which will line up the intake bolt holes, and you will be all set.

 

[MechEngr]

Thanks for you input!!

 

[rumblefish360]

1998 magnum 360
stock rods & crankshaft
KB-107 pistons +.030
PIE stage 1 EQ heads
Comp Cam 20-746-9
*** Edelbrock Performer RPM Intake Manifold (7577) ***

I'm building this 360 magnum for my 1967 Barracuda and am questioning my choice of intake manifold and am hoping for some experience/guidance from the experts.

I have 2 concerns with intake manifold:
1 - The heads have coolant ports at both the front and back of the heads. The Edelbrock manifold only has coolant ports at the front of the manifold and my concern is lack of adequate cooling for the cylinder heads.
2 - There is a significant mismatch with the ports on the engine -vs- ports on the manifold.

It might be that this intake was only intended to be used with Edelbrock Performer RPM heads.

I guess I could modify the intake gasket to accommodate the Edelbrock mismatch, but even with that I think I would end up with slightly restricted flow due to the mismatch. My other option is just to look for another intake manifold that has the proper coolant ports.

Any sage advise out there?????

View attachment 1716079441

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I have a 5.9 w/a RPM, 740 AFB, hooker super comp headers @-1-3/4.

The lack of a cooling port in the intake at the back of the intake is a non issue and works like stock. Take notice of the head gasket which cover a cooling hole in the block to head. This is needed because the Coolant would just come into the head and up to the thermostat.

This forces the Coolant to the rear of the block and up into the head at the rear and then to the front of the engine and up to the thermostat. This is how it works.

If your running a very hot engine, performance wise and also temp wise, tapping the rear of the intake s possible to do.

I’ve been running this stock long block and RPM intake for a long time now without issues.

 

[MOPAROFFICIAL]

I just look at the kegger that came of the engine and it doesn't have coolant ports on the rear of the intake manifold. I wouldn't have expected this!

Want to see something uglier?
This is how much smaller the stock intake Port windows are to an Edelbrock Magnum intake gasket... as for advice, how about using an Edelbrock intake gasket.

 

[66Valiant528]

318 port 340 gasket . I thought all Magnums had the larger 340/360 port?

 

[rumblefish360]

Tweener I think.

 

[MechEngr]

Want to see something uglier?
This is how much smaller the stock intake Port windows are to an Edelbrock Magnum intake gasket... as for advice, how about using an Edelbrock intake gasket.

View attachment 1716079538

The Felpro intake gaskets that I have are almost perfectly matched to the ported heads. I will look at the edelbrock gaskets to see if they are a better fit. Thanks for the suggestion.

 

[MOPAROFFICIAL]

318 port 340 gasket . I thought all Magnums had the larger 340/360 port?

Nope. In between.

 

[mopar65]

1998 magnum 360
stock rods & crankshaft
KB-107 pistons +.030
PIE stage 1 EQ heads
Comp Cam 20-746-9
*** Edelbrock Performer RPM Intake Manifold (7577) ***

I'm building this 360 magnum for my 1967 Barracuda and am questioning my choice of intake manifold and am hoping for some experience/guidance from the experts.

I have 2 concerns with intake manifold:
1 - The heads have coolant ports at both the front and back of the heads. The Edelbrock manifold only has coolant ports at the front of the manifold and my concern is lack of adequate cooling for the cylinder heads.
2 - There is a significant mismatch with the ports on the engine -vs- ports on the manifold.

It might be that this intake was only intended to be used with Edelbrock Performer RPM heads.

I guess I could modify the intake gasket to accommodate the Edelbrock mismatch, but even with that I think I would end up with slightly restricted flow due to the mismatch. My other option is just to look for another intake manifold that has the proper coolant ports.

Any sage advise out there?????

View attachment 1716079441

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View attachment 1716079445

You need to send that intake to Pitsburgracer and have him do his porting magic to the intake ports. But cool build nonetheless. The as cast ports of my indy 360 magnum intake needed some porting to match the Felpro intake gaskets I was useing.

 

[mgoblue9798]

Just a heads up before you buy head gaskets, build the short block and check to see how far the pistons might be out of the magnum block. May need a thicker head gasket than the usual .039 felpro

 

[MechEngr]

Thanks for the caution. I did check the piston to deck height and the piston is .002" below the deck. The stock pistons were setting .060 below the deck and the calculated CR was around 8.8:1. I went to the KB-107 piston to increase the CR and was aiming for a calculated CR around 9.5:1. I believe that I'm now actually more like 10.5:1, which is a lot more than was expected.

 

[mopar65]

Thanks for the caution. I did check the piston to deck height and the piston is .002" below the deck. The stock pistons were setting .060 below the deck and the calculated CR was around 8.8:1. I went to the KB-107 piston to increase the CR and was aiming for a calculated CR around 9.5:1. I believe that I'm now actually more like 10.5:1, which is a lot more than was expected.

I run my 11.1 compression 360 magnum on 93 pump gas.

Thanks for the caution. I did check the piston to deck height and the piston is .002" below the deck. The stock pistons were setting .060 below the deck and the calculated CR was around 8.8:1. I went to the KB-107 piston to increase the CR and was aiming for a calculated CR around 9.5:1. I believe that I'm now actually more like 10.5:1, which is a lot more than was expected.

I have a build close to your engine. Mine is as follows
2000 360 magnum
Stock bore
KB107 pistons
Stock rods with ARP rod bolts
Stock crank
Comp 555 or 550 solid lift cam
Trickflow heads
Felpro 1008 head gaskets
Indy 360 magnum single plane intake drilled for LA bolt pattern.
Compression comes out to 11.1
I run and race the engine on 93 pump gas. When my friend had the engine with EQ heads he also raced it on 93 pump gas. I think you will be surprised how good these little magnum engines can run with a little compression added to them.

 

[AJ/FormS]

Just for reference:
My Eddie-headed 367LA has been running on 87E10(street) since 1999.
The Scr has varied from 10.7 to 11.3 and the Cylinder Pressure has varied from 177 to 195psi. The KB107s are currently about .005 or better out of the holes, making the Q with the .039 FelPros to be .034>.032.
In the Early years, this engine was freshend up every winter five times in a row; because it was my DD; and I stuffed a 318 into it for the winter.
Each winter, three times in a row, I avoided catastrophe, from various shortcomings of various machine shops. The fourth was a charm. I did it one more time, and it was again solid, so that was the end of her freshenings. Shortly after that I got a better paying job, sold the 318, and the Barracuda was retired from DD duty.
Not once was there any evidence of Pre-ignition/Detonation (and I don't baby her), and, in fact, I finally replaced the sparkplugs last fall (October) for the very first time; not because they needed it but because I thought the car was sold, and new plugs were a part of the deal. My guess is that those plugs had to have, close to or better than, 100,000miles on them.
A long time ago I put out a thread here on FABO, asking what pressures and fuels guys were running with their Alloy heads. I heard numbers as high as 205psi, on 94gas. But more typical was 185ish psi. Most guys are NOT running 87. Most are running 91. Nobody wants to run Ethanol.
My Barracuda ran 93mph in the Eighth, on it's only run ever..... on that stinking 87E10 with no adjustments from street-tune. I just drove it an hour to the track, dropped the exhaust, made the run, didn't break anything, bought some merchandise, ate the crappy track burgers, watched the funny-cars, reinstalled the exhaust, and went home. Had a great day with my 20 year-old son.
My secret?
is a 2-stage timing curve that slows down after 2800 rpm, and is delayed to not be all-in until about 3200/3400. All-in for this girl is 32>34 degrees.
In the intervening years, the cost benefit of running 87 versus 91, has bought me a lotta goodies; I know it paid for the Eddies, a long long time ago.
Jus food for thought.

Oh yeah, I'm retired now, so thinking of freshening that 367 this coming winter. She's a great engine!

 

[rumblefish360]

An! You should just get a perma link to that statement.

 

[RLF Cuda]

I like to port match the heads to the manifold, but probably more important is to make sure the bolt holes line up between the manifold and the head. They can be off if the block and/or heads are surfaced even a little. I stripped the threads on a head due to forcing the bolt to start in a misalligned hole. My Bad. Take head off and helicoil it.
The porting is straight forward and you can get the bits and die grinder from Harbor Freight. Will work for at least one set of heads. Just match to the gasket and smooth into the port both directions. Nothing fancy. But how much power is it worth? Don't know. Probably no that much, but it makes me feel like I did something.

 

[chouston]

I have a build close to your engine. Mine is as follows
2000 360 magnum
Stock bore
KB107 pistons
Stock rods with ARP rod bolts
Stock crank
Comp 555 or 550 solid lift cam
Trickflow heads

Saw your info and was thinking about using KB107 4.000 pistons in a donor 99 dodge 360 magnum for my 99 Dakota rt. Just checked #1 stock piston and it is .044 below deck height. What r ur thoughts on using the KB107, seems to me they will be above my deck height a fair amount...........

 

[rumblefish360]

Saw your info and was thinking about using KB107 4.000 pistons in a donor 99 dodge 360 magnum for my 99 Dakota rt. Just checked #1 stock piston and it is .044 below deck height. What r ur thoughts on using the KB107, seems to me they will be above my deck height a fair amount...........

View attachment 1716182853

You can search for a more “Magnum” specific piston or use the KB-107’s with a thick head gasket. Cometic will custom make a head gasket for you if a regular one is not available in your thickness.

For an example, if the piston is .015 out of the hole, and you want a .035 clearance
(your call really, this just an example)
A Fel-Pro head gasket @.050 thick should be possible.

If you wanted to run a quench clearance of .032, a Cometic gasket should be custom ordered. IIRC, there thinnest gasket is a .027. They can make you a gasket at a .100 or thicker if you want.

Run your thoughts on this through a compression ratio calculator as long as you know how much the piston protrudes above deck and your cylinder head cc amount.

 

[mopar65]

Saw your info and was thinking about using KB107 4.000 pistons in a donor 99 dodge 360 magnum for my 99 Dakota rt. Just checked #1 stock piston and it is .044 below deck height. What r ur thoughts on using the KB107, seems to me they will be above my deck height a fair amount...........

View attachment 1716182853

I could say go for it. But not knowing what's all been done to your block etc. I would do what Rumblefish said. It's been a long time sense I put the trickflow heads on my magnum 360. But if I remember right the KB107 pistions were right at deck height or a thousands or two below it. I am useing the KB107 pistions with a felpeo 1008 head gaskets. My cranking compression is around 165/170 psi. Here is a picture of my KB107 pistion in my 2000 magnum block

 

[chouston]

Thanks for the info, just started taking 1999 donor block apart, original owner said approx. 95,000 miles before Durango rusted out on him. Cylinder walls look very good, with great original crosshatch. I calculated, pistons above deck .008. Good to hear yours were at/near deck height. Option 1, top end only: KB107 pistons, Hughes: Airgap intake, big gulp tb and possibly one of their cams, Intake: PIE magnum eq heads w/ 2.02 ex valves.

 

[67Dart273]

Coolant ports

ALL American SB's that I can recall are made this way, Ford, GM, Mopar. They are made this way because the heads are reversible side to side, and therefore must be non "left or right."

Actually some racers add fittings to the rear ports and hook hoses in to increase coolant. Who knows if it really helps except in extreme HP cases

 

[rumblefish360]

Rear coolant lines help keep the cylinder head more evenly cool across the whole head. This is worth some power. No sense in having one side of the head hot possibly detonating!
MoPar suggests taking it out of the center in some of there writings.

If you only added rear lines, it’s a plus. If you did rear and center, that’s as good as it gets for removing coolant out of the head.