Performer rpm package?

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fnaramore

fnaramore

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Hey guys, got a 73 swinger with a 318 with a weiand stealth, 600 edelbrock, comp XE256H, 2.25 in exhaust from the manifolds back and timed 10* BTDC. This summer I am looking to swap out my heads for edelbrock performer rpm heads and maybe switch my weiand for a performer rpm manifold. Anyone have an opinion on performer rpm cam vs. a comp cam XE268H or this setup? Its a three speed automatic with the stock stall and 2.73 rear end.
 
Can't comment on the Ede cam,but I can the XE268.
I run this cam in my mild 360,and it pulls hard.
One of the top recommended Cams on this site.
 
What's been done to the 318??? Seems like a mismatch of parts if it's a stock bottom end with a 2.73 rear.
 
I think those heads have 2.02 intake valves, yes? If so don't you need some work to create clearance in the top edge of the block. This was always the case putting old Chrysler X heads on a 318, otherwise the valve edge catches on the top edge of the block and mayhem ensues! Heads with 1.88 valves, like 360 heads work fine.
 
All that's been done to the engine is what I have listed. Its the original with an original 76,000 miles. I would like to swap the rear end to a posi with like 3.73s. And your right str12-340, the intakes are 2.02. Didn't know that issue exists, thanks for the heads up!
 
Just some stock 1.88 360 heads have them milled .040 or so and use a thin head gasket your cr even with the mill will be low. Also have the intake side milled use a small cam in the 218 to 220 @.050 range. Or do up a 360 and then use the eddy stuff you mentioned.
 
EL5DEMON340 said:
Just some stock 1.88 360 heads have them milled .040 or so and use a thin head gasket your cr even with the mill will be low. Also have the intake side milled use a small cam in the 218 to 220 @.050 range. Or do up a 360 and then use the eddy stuff you mentioned.
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Would 220 to 234 at .050 just be too much? Thats what the comp XE268H is. My current cam is 212-218, just figured I'd get more outta the new heads with a more aggressive cam
 
with a stock bottom end 318 i would stay right around 220 @.050. the eddy heads and rpm intake would be a little much for this engine.
 
str12-340 said:
I think those heads have 2.02 intake valves, yes? If so don't you need some work to create clearance in the top edge of the block. This was always the case putting old Chrysler X heads on a 318, otherwise the valve edge catches on the top edge of the block and mayhem ensues! Heads with 1.88 valves, like 360 heads work fine.
Click to expand...

No bore notching is necessary. It is possible to put a 2.05" intake valve in a 318 bore without bore clearance issues.
 
fnaramore said:
Hey guys, got a 73 swinger with a 318 with a weiand stealth, 600 edelbrock, comp XE256H, 2.25 in exhaust from the manifolds back and timed 10* BTDC. This summer I am looking to swap out my heads for edelbrock performer rpm heads and maybe switch my weiand for a performer rpm manifold. Anyone have an opinion on performer rpm cam vs. a comp cam XE268H or this setup? Its a three speed automatic with the stock stall and 2.73 rear end.
Click to expand...

The Edelbrock heads and intake manifold with the XE268H will light a fire in your 318. If you do as others have suggested and put some gears (even 3.23) in there, it'll be a stormer.
 
I think right now your big restriction besides the rear gear are the stock 318 exhaust manifolds. you would notice a great improvement with even a cheap set of headers.
 
IQ52 said:
The Edelbrock heads and intake manifold with the XE268H will light a fire in your 318. If you do as others have suggested and put some gears (even 3.23) in there, it'll be a stormer.
Click to expand...

Are you positive the 2.02 intake valves will clear and you think a XE268H would be perfectly fine?
 
fnaramore said:
Are you positive the 2.02 intake valves will clear and you think a XE268H would be perfectly fine?
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x2 with IQ... especially on the gearing change and headers. I'd bet with just those two and what you have it would be a barnstormer.
 
Okay cool! thanks for all the info guys! My last real question then is I was talking to comp cams since they say XE268H needs an adjustable valvetrain, but the guy I was talking to there made it seem like that I could use my stock rockers provided I take the time to measure the preload on the stock pushrods and then buy longer or shorter ones as needed. Does this sound correct?
 
fnaramore said:
Hey guys, got a 73 swinger with a 318 with a weiand stealth, 600 edelbrock, comp XE256H, 2.25 in exhaust from the manifolds back and timed 10* BTDC. This summer I am looking to swap out my heads for edelbrock performer rpm heads and maybe switch my weiand for a performer rpm manifold. Anyone have an opinion on performer rpm cam vs. a comp cam XE268H or this setup? Its a three speed automatic with the stock stall and 2.73 rear end.
Click to expand...

You know,, because your engine is still together, and running, and by your description should be very strong, except you're beating your head against the wall because of your gear and exhaust limitations..

I humbly suggest that instead of spending over a grand$ on heads, cam, etc.,, you give the engine you have, which should be very stout, a chance to show it's stuff..

Headers and Gears are the most cost effective mods you can make,, so to keep trying to make more H/P while shackling/choking the engine, just doesn't make sense, imho..

Spend the $$$ on gears and exhaust,, you will see/feel/have more usable H/P that you already have...

Then if you want more power,, you'll have the platform to USE more power, and you will actually feel the improvement to it's full value.. jmo

hope it helps
 
I plan on doing the rear end very soon, I just wanted to finish up the valve train and the exhaust system on there now is a custom made system specifically designed to let if breath more than you might think. I know this statement is gonna make someone bent out of shape and say its not the same as headers, but I have done the work behind the airflow numbers. Finally putting my physics degree to use! haha but definitely thanks for your opinion man! I always wanna hear what people have to say.
 
Alright, just finished some good long talks with both comp cams and edelbrock. Looks like I am gonna go with performer rpm heads, the XE268H cam and then use a comp pushrod length checker to buy the proper length pushrods for preload so I can use my stock rocker arms. Most likely also gonna keep my weiand stealth for the time being since the ports are only .21" less in height than the performer rpm manifold. If anyone thinks I am on the brink of destroying my engine or has any suggestions, lets hear 'em
 
Is the low (1973) compression and small cubes, going to work well with the big valves/flow and fairly aggressive cam? Seems like it's not a great combo unless the comp. is brought up at least.
 
I don't think there's any disaster looming with that combination, but like all the comments pretty much sum up:

If you're going to the trouble to upgrade the engine's top end, you'll need gear and realistically a stall. That XE268 isn't a big cam really, but anything over stock will benefit by allowing the engine the freedom to hit the powerband quicker.

and the exhaust system on there now is a custom made system specifically designed to let if breath more than you might think
Click to expand...

Please do enlighten us...
 
Kevin Jonker said:
Is the low (1973) compression and small cubes, going to work well with the big valves/flow and fairly aggressive cam? Seems like it's not a great combo unless the comp. is brought up at least.
Click to expand...

Ahh yes, the constant back and forth of compression vs flow...I'm usually on the side of compression with good flow, but realistically, if he uses the Edelbrock heads, he might actually get a bump in compression to about 8.5:1. And despite the larger numbers on the 050 duration, the small advertised duration will keep some cylinder pressure in check-especially if he were to perhaps advance the cam a couple degrees-old trick that still works pretty well with lower static compression. That being said, the increased flow will still benefit his combination-especially if all other aspects are commensurately updgraded; e.g., induction, exhaust, gears, stall, suspension, and chassis.

Would it benefit from more compression? Yes, but for a streetgoing engine, it'll still run fine I bet, IMO

EDIT: btw, the CR figure I stated above is assuming pistons .080" in the hole, an .039"x4.1" gasket, and 63cc chambers as advertised by Edelbrock.
 
Thanks for your opinion txstang84! Engine has a 8.6 compression and should go up more when the heads go on kevin
 
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