First time swapping edelbrock aluminum for 915 cast iron heads.

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LovetheA's

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I’m planning on doing my first head swap on my 383 in my 67 Dart. I’m going from 915 cast iron to aluminum edelbrock performers. I’ve watched a few instructional videos on YouTube but still have a few questions. I though I’d put some questions out there for help. I’ll be swapping my Harland Sharp roller rockers over to my otherwise complete Edelbrock Performer heads.
Can I just reuse my pushrods and lifters? If so should I make sure same lifters and pushrods go back in the same location?
Do I need any type of modification or spacers/shims when moving my Harland Sharps over to the Edelbrocks from cast iron head?
What lubricants/supplies will I need other than listed?
Anti-seize for ARP bolts
Gasket sealer for head to block surface.
Oil for various contact points metal to metal.
Any other brake-in lubricants?
Any other suggestions welcome. Thanks
Carl
 
the edelbrock performers are a stock style replacement head. you should be able to reuse pushrods but make sure to check valve train geometry after the switch. and yes every pushrod and lifter needs to go back in the same spot, although for a head swap you should not need to pull lifters. easy way to keep pushrods in order is to take a piece of cardboard and punch holes in it the same way the pushrods would be oriented in the motor and mark which way is the front of the engine, as for if you will need shims its best to assemble it and check valve train geometry as i said, and make adjustments as neccesary
 
do not remove lifters. most head gaskets do not want sealer added. pour oil on the valves , retainers, springs. rockers and pushrods should go right on
 
Upon doing some further reading I came upon something I didn’t realize. The edelbrock aluminum performer rpm heads which I’m swithcing to from my 915 cast iron heads have angled spark plugs. It says that the plugs are angled 15% towards the exhaust valve. I’m wondering if that is going to be a problem with my Schumacher tri-y headers going on? Well I guess I’ll find out soon enough. To answer a previous question in this post. Yes I already bought the heads and had them gone over for any inconsistencies and corrected by a local machine shop I trust.
 
Upon doing some further reading I came upon something I didn’t realize. The edelbrock aluminum performer rpm heads which I’m swithcing to from my 915 cast iron heads have angled spark plugs. It says that the plugs are angled 15% towards the exhaust valve. I’m wondering if that is going to be a problem with my Schumacher tri-y headers going on? Well I guess I’ll find out soon enough. To answer a previous question in this post. Yes I already bought the heads and had them gone over for any inconsistencies and corrected by a local machine shop I trust.


It isn't a problem. I ran RPM heads with Schumacher headers
 
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The pushrods should work - but as noted you need to check. If the cam is hydraulic, preload is important and aluminum heads expand more, so watch the preload and make sure it's good. Also use the Felpro Performace gaskets for the aluminum heads. Make sure the intake will fit properly too - if the 915s were rebuild years ago or milled the intake may need attention.
 
I've been thinking of a similar swap to replace my 915's. How much of a performance gain are you expecting red? Are you also going with a large can?
 
What's gonna happen to your cylinder pressure?
Aluminum needs more pressure to break even.
Then they like 175 to be aggressive. Then they like 185psi to wake up
Some guys are over 200 on pumpgas,they say, IDK,I haven't tried it yet..
I run 185 on 87E10,in my 367
 
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What's gonna happen to your cylinder pressure?
Aluminum needs more pressure to break even.
Then they like 175 to be aggressive. Then they like 185psi to wake up
Some guys are over 200 on pumpgas,they say, IDK,I haven't tried it yet..
I run 185 on 87E10

Not if they outflow the iron heads. I went from 906's to eddy heads that were blueprinted and mildly ported. 88cc chambers on both.
 
Not if they outflow the iron heads. I went from 906's to eddy heads that were blueprinted and mildly ported. 88cc chambers on both.
Lifters have to go back in the same hole, why pull them to change heads tho?. PUSHRODS DO NOT AS LONG AS THEIR STRAIGHT AND IN GOOD SHAPE. I would almost bet u will need longer pushrods w/ alum. heads too.
 
I’ll try to answer some of your questions everyone. I believe my original 915 heads chambers if they weren’t milled down are at about 78cc and the previous engine builder about 15 yrs ago said the compression with the 915’s was at about 9.8 to 1. The cam is 284 duration 484 lift and it’s in a 4 speed. The motor has about 10,000 miles on it after about 15yrs. It still runs great at about 30-40 psi oil pressure hot at idle. I had the edelbrock rpm performers freshened up by a machine shop I trust. They say they are bolt on but I never trust that statement. The heads were milled slightly to be true and mildly ported. Originally they had 75cc chambers but my guy at the machine shop said after milling they are down to about 72cc. So assuming the gasket is a similar thickness to what was pulled off I’m thinking I’ll come in with slightly higher compression about 10.2 to 1. The gaskets I purchased are cometics .020 thickness. I’m hoping I can get away with running 93 with no probs. I’m hoping for about a 40 horsepower gain over the old 915’s. I’m a little concerned about the comment on needing different pushrods? I thought all I would have to do was swap over my Harland sharps off my 915’s put everything back and I would be good to go. What does everyone think? I’m interested for input.
 
Which 284/484?
In either case, 10.2 is in the ballpark for iron
IMO, you don't have nearly enough compression for for aluminum. At 10.2 you're bottom-end is barely stronger than a 318, and you'll need a hi-stall to get moving in hi-performance fashion.
I'd want at least 11.2 ,perhaps 11.6 with the108LSA, in straight up; that 's still less than 180 psi. That short stroker could run even more pressure.I've run 10.9@185psi on 87E10, in my 367
If you're limited to 10.2,and aluminum, I'd slam the intake shut a lot sooner, like maybe an ICA of 58*. Even that ain't right ...the bottom end is getting disproportionately strong ,compared to the top. You just need more compression.
That's what I think.
 
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AJ/Forms
Much of what your saying is beyond what I understand. Engine building definitely isn’t my forte. I’m learning as I go along. Not to discount that I’ve learned a ton from this website. My original motor ran really strong with just basic 915’s, no porting or anything special, older mopar performance 284 duration 484 lift cam, KB pistons, 9.8 to 1 comp. Harland sharp roller rockers, Edelbrock Performer intake, speed demon 650 cfm, 4 speed trans. It dynoed at 340 rwhp about 380 rwt. I’m changing out the 915’s to edelbrock rpm performers with a bump in compression to about 10.2 to 1 with the mild porting and milling which reduced the size of the edelbrock chambers to 72cc from originally being 75cc. I don’t understand why the motor is going to fall flat with those chambers. I know that a lot depends on how quick the cam reaches maximal lift and how long the valves stay open and close but I don’t know the original specs on the original mopar performance b/rb cam. Keep in mind this motor ran great on 93 octane no pinging even on hot summer days. I think that was due to original comp being 9.8 to 1. Now I know aluminum heads can run higher compression before pre detonation so I though 10.2 to 1 should work great. Why would you want to run up to 11.2 to 1 compression with the edelbrock’s and risk pre detonation on pump gas? Is the 180 your referring to the optimal cylinder pressure? I’m changing out the carb to a 850 cfm race demon and please explain where I going wrong because I don’t see how the motor is going to fall flat? Can people please explain in layman’s terms?
 
AJ/Forms
Much of what your saying is beyond what I understand. Engine building definitely isn’t my forte. I’m learning as I go along. Not to discount that I’ve learned a ton from this website. My original motor ran really strong with just basic 915’s, no porting or anything special, older mopar performance 284 duration 484 lift cam, KB pistons, 9.8 to 1 comp. Harland sharp roller rockers, Edelbrock Performer intake, speed demon 650 cfm, 4 speed trans. It dynoed at 340 rwhp about 380 rwt. I’m changing out the 915’s to edelbrock rpm performers with a bump in compression to about 10.2 to 1 with the mild porting and milling which reduced the size of the edelbrock chambers to 72cc from originally being 75cc. I don’t understand why the motor is going to fall flat with those chambers. I know that a lot depends on how quick the cam reaches maximal lift and how long the valves stay open and close but I don’t know the original specs on the original mopar performance b/rb cam. Keep in mind this motor ran great on 93 octane no pinging even on hot summer days. I think that was due to original comp being 9.8 to 1. Now I know aluminum heads can run higher compression before pre detonation so I though 10.2 to 1 should work great. Why would you want to run up to 11.2 to 1 compression with the edelbrock’s and risk pre detonation on pump gas? Is the 180 your referring to the optimal cylinder pressure? I’m changing out the carb to a 850 cfm race demon and please explain where I going wrong because I don’t see how the motor is going to fall flat? Can people please explain in layman’s terms?

Hang on, I didn't say anything about falling flat.
There's three basic reasons to go with alloy heads.
1) detonation resistance
2) workability
3)efficiency.
If you spend all that money, for just one of the three, you are kindof cheating yourself. Sure, you bump up the flows pretty good, and slam a cam in there and go have a good time.
But if you don't take advantage of the heat characteristics of those heads, you're A) sticking way more cam in there than you need, boosting the power-peak up into an area you only rarely drive, and/or
B) leaving some performance on the table at other rpms.
...By increasing cylinder pressure from 155s to say 175plus, you can bring the power-peak down and fatten up the midrange, and if you care; design a cam to drive a little further down the road on less dollars, burning a lower grade of fuel.
...As to optimum pressure I can't say.In my 367, I have run 175 to 190,and more, on 87E10 (R+M)/2 Canadian gas with full timing, since 1999. IMO the bottom end is outrageous(lol) for a 367 streeter, And I give the credit to the pressure. This with a 230cam now

Here are some example of what happens to the low-rpm performance, with changing pressure. This is kindof important to a stick-car. I'm gonna assume you have the 114LSA cam, on account of you don't mention the idle lope. All these are alloys except yours in red.All should run on pumpgas, with proper Q. These are just for demonstration purposes.I will list the Wallace results as ;

-Scr---ICA---Dcr---psi---VP
9.80/74*/7.13/138/110VP this is your iron headed 383,and 284/284/114 cam
10.2/74*/7.41/145/116VP your proposed combo; alloys at 10.2
11.5/78*/7.97/159/121VP compression upped/ cam retarded
11.5/72*/8.47/172/141VP cam advanced
_____________________________________________________________

11.8/74*/8.52/173/139VP compression upped,cam retarded
11.8/76*/8.36/169/133VP compression upped, cam retarded to kill some VP.
I didn't bother going any higher, cuz I see the Scr getting excessive.
_____________________________________________________________________
With a 276/284/110 cam
11.2/68/8.62/176/151 in straight up. one size down cam,60* o/lap versus your 70*
____________________________________________________________________

Notice the VP numbers;
compare the blue to red. The VP is just 116/110=plus 5% stronger than your current combo.
Next, compare the violet line, to the blue; At 141/116=plus 21.6% stronger than your proposed combo.
Finally compare the green to the blue;151/116=Plus 30%. Where do you want your power to be?
At 151 (same as I have), this is a dump-it-and-go deal with a 10.97 starter gear. Just a blip of the throttle to put some energy into the flywheel and more or less dump the clutch and go. With 3.55s and a 1.91 second gear, this will break the 295s loose at up to 50 mph.

Remember, VP is just a number we use to help understand low-rpm performance changes .
Read about VP here V/P Index Calculation
Wallace Racing: Dynamic Compression Ratio Calculator
 
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I'm sure you will be fine. Contact a cam company like Comp Cams and give them all your info. They will guide you properly. One of the other guys said to check your geometry- measurements. Research that.
 
I don't see a problem, I'm running '67 383 in my Barracuda FB w/ Edelbrock E-street w/75cc @ 10.25 compression & a Comp XE274 w/1.6 rockers & its my daily, makes good power & I ran 12.8@108 in the 1/4 w/stock converter 727 & 4.10 gears.
 
I don't see a problem, I'm running '67 383 in my Barracuda FB w/ Edelbrock E-street w/75cc @ 10.25 compression & a Comp XE274 w/1.6 rockers & its my daily, makes good power & I ran 12.8@108 in the 1/4 w/stock converter 727 & 4.10 gears.

This is exactly what I mean
I ran 12.9/106 with 223cam and 10.9 compression at 3650 on 245/60-14 streets, spinning most of the way. A833 and 3.55s, also my daily....all summer, May-long to Oct 10th

Static compression ratio of ......................10.9:1.
Your dynamic compression ratio is ........... 8.91:1 .
Your dynamic cranking pressure is............ 183.76 PSI.
V/P (Volume to Pressure Index) is ............162

Yes on 87E10

Edit; that was in 2002
 
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Which 284/484?
In either case, 10.2 is in the ballpark for iron
IMO, you don't have nearly enough compression for for aluminum. At 10.2 you're bottom-end is barely stronger than a 318, and you'll need a hi-stall to get moving in hi-performance fashion.
I'd want at least 11.2 ,perhaps 11.6 with the108LSA, in straight up; that 's still less than 180 psi. That short stroker could run even more pressure.I've run 10.9@185psi on 87E10, in my 367
If you're limited to 10.2,and aluminum, I'd slam the intake shut a lot sooner, like maybe an ICA of 58*. Even that ain't right ...the bottom end is getting disproportionately strong ,compared to the top. You just need more compression.
That's what I think.
Yep ... the Op doesn't have a snowballs chance in hell with that measly 10.2 compression. Not nearly enough compression . What a turd it will be. 11.6 ? nah . How bout 11.750? I won't be happy until my street car is on the ragged edge of detonation to gain that last 5 lb-ft and 4 hp. That's what I think.
 
So it sounds like A/J is saying he would try to bump the compression up some more. So now suggest how he should increase compression A/J.
 
And you are saying the cam would be to big (484 lift) with his combo. Right A/J?
 
And you are saying the cam would be to big (484 lift) with his combo. Right A/J?

NO...I'm saying there is so much more potential in the combo
that at higher pressures that you could easily give up some duration.........if you wanted some some more bottom-end and midrange. OP didn't state how he intends to use this vehicle so I can't speak to the cam choice
The 284/484/114 cam is about 241*@.050 ..This is pretty big for a SBM streeter, maybe not for a BB,but at 10.2 with alloys it's gonna be a little soft on the bottom.
The clutch will help get the engine thru that, but it won't be a dump-it-and-go deal.
The lift is,even with 1.6 arms (and .516 lift),barely tapping into the alloy's potential.
That cam may not wake up until around 40mph with 3.55s. It's a good thing the 67 Dart is one of the lightest of the later generation A's, and the 383 is a typically pretty good on power.
So the bottom line to me is;installing just alloys is a lot of money for very little gain.I like to get the most bang for my bucks.
But OP says he was happy with the iron combo, and since the parts are already chosen, we'll have to see how it plays out.
And that is my opinion.
 
This is exactly what I mean
I ran 12.9/106 with 223cam and 10.9 compression at 3650 on 245/60-14 streets, spinning most of the way. A833 and 3.55s, also my daily....all summer, May-long to Oct 10th

I run 11.70's @160psi cranking compression. static 10:1. 242@.050, 112LSA. (and it is anything but soft on the bottom) It makes 550ft/lbs at 3500rpm and goes idle to 3500 like cracking a whip. I'm definitely leaving power on the table in several areas, cam, combustion chamber volume, tires, convertor. But it drives real nice on the street to and from that strip and runs consistent as hell.

I can't see putting any money into an iron head given the cost of a decent aluminum head. And they leave you room to grow.
 
In 2004
my 367,now with a 230* cam, drove 55 minutes to the airport track, clicked off a 93 in the 1/8th, and went home, one successful run of 4 attempts.
That ,Mr. Wallace says, equates to over 115 in the qtr.
On this day I was at 3467 pounds,and running 3.55s, and Mr. Wallace thinks that might be 425hp.

So, Like I said; I'm at 10.9Scr, with a little 230 cam,And aluminum heads ,now at 180psi/153VP.
If I would get my 60ft out of the mid 2.2s, my car might trap right alongside a hot BB.

I'd run more pressure but my Q is already down to .034, So I'd have to tear down the engine and modify the crowns before taking it to the next level. With all the money I've saved running 87E10 for over 100,000 miles, I should have enough money in the piggy bank to do that, but at age 64, the novelty is rapidly wearing off.
BTW
a VP of 162 in a 367 is freeky awesome,and 153 is only a little less so. The gain in top-end power,going from a 223 to a 230 was most definitely worth sacrificing the 9 points of VP. 153 is still more than street tires can deal with in a street car with street suspension.
The 292/508 was definitely worth tossing. It made fantastic power, in an rpm range that I rarely drove.With 3.55s, 60mph was 6800 in first.The VP with that cam was down at 143 or less, and with 3.55s was unacceptably soft for me. I moved it 3 times and said "enough,you're outtahere." I ran 11.3Scr with that one, and up to 180 psi .


So I can't tell if you guys are ragging on me, cuz, nobody says something like "AJ I don't agree with what you're saying, and here's why" so I just have to let my results speak for themselves.

And besides,as to the Wallace numbers, I clearly stated ;"These are just for demonstration purposes" And I included links for perusal
 
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