Edelbrock Heads

[jdscofield]

Has anyone purchased the Edelbrock E street heads for big blocks?  Was wondering if anyone had an opinion of them once they used them.  I'm considering purchasing the 75cc ones for my 400

[ottawamerc]

Ya I bought them and thus far I'm happy with them, although not issue free. Problems encountered were my MSD RTR dizzy wouldnt fit as it hit the head casting, I had to grind some material off of the head and the distrib to get it to fit, the angled spark plugs have some clearance issues on #1 #3 cyls. I used the stock rockers and theres some rattling noise but not crazy. OTHER than that there great

Scott

[jdscofield]

Hey Scott,

Did you purchase them assembled and have to go back to your stock rockets?  When you say clearance issues, are you referring to issues with the plugs and headers and did you use the recommended spark plugs as per Edelbrock?  The Edelbrock rep made it sound as they were plug and play.  Also, did you notice an immediate difference the moment you were able to take it out for a ride?

[XH29N0G]

I thought the e street heads had straight plugs.  I know little about them, but have seen discussions comparing them to stealth and mopar 452 heads.  Let's see if others chime in.    

My understanding is that they can either come with or without valves, locks, springs installed, but will not have rocker arms and shafts.  Also that it is advisable to have someone who has experience (a machinist) look them over.   I have also heard that it can be good to know what your compression is like (compression test) before upgrading.  I do not know if it is because a new top end on an old bottom end may result in more blow by the rings, but I also assume a lot of people have done this and it has helped.

FWIW, I changed the cam and put heads on a 383 and noticed a difference.  I noticed a bigger difference when I changed the rear gear ratio though, but that is a different issue.

[jdscofield]

Hey XH29N0G,

I just rebuilt my 400.  it took the guy 5 months to somewhat give me my specs.  I told him I wanted to push 400 horses out of it and that I wanted my compression at 9.5:1 minimum.  When he finally gave me some of the specs over the phone, it had 8.75:1 compression.  yes, it's better that the advertised 8:1 compression (most 400's really had compression ratio's in the 7's), but it's not what I wanted.  I believe the lower compression ratio limits me to extreme mild cams.  I told him to work the heads and he didn't touch them.  So now I have a 400 with the following:

400 block
.30 overbore
10 bearing
hypereutectic pistons
mild cam  272/454 .272/.454
compression 8.7:1
stock heads
edlebrock performer RPM dual plane high rise intake
Holley 750 double pumper
headers
flow masters
2700 rpm stall
373 drive ratio

I don't know if I'm going to be happy with it.  The tranny went out 20 miles after the engine was installed and I got laid off shortly after.  I think I'm only going to pull 300 horses at best.  Once I get the tranny repaired and finish breaking in the engine, i'm gonna have it Dyno'd.  Who knows, maybe it will perform better than I expect it will, but this is why I'm considering the Edelbrock heads

[XH29N0G]

Let's hope some others pipe in.  There is a lot of knowledge here and I would wait to decide until you have it.

My understanding is that the 75cc will help to change your compression and this may make a significant difference.  I also assume the flow will make a difference.  It will probably be worthwhile knowing ahead of time exactly what sort of compression you are likely to end up with.

I understand there are differences in the manufacture of the different heads and there are a number of people on here who can provide sound advice. 

I assume you have searched through the various threads on the forum and are specifically wondering about the e-street versus the other heads.  There is also information that I find informative on the proven engine combos sections.

[Brass]

My understanding is that the E-Street heads share the same casting as the RPM heads (they cost almost as much) with the same flow numbers.  But the valves/seats/springs are different.  Edelbrock recommends using adjustable rockers and keeping RPM to 5500.  Also, the 75 cc chamber version will probably give a bump in compression over stock.  (How much and what the final static compression would be depends on multiple factors.)  Do a search on this site – there has been some prior discussion regarding these already.  But I too would love to hear how they improve performance on a low comp motor.  I intended to get a set and find out - but ultimately had to delay that plan. 

[cudaken]

jdscofield, your Machine shop sucked on this build.

Eddy heads are going for what, $1300 plus these days? 

Personally I would do 1 of 2 things first.

1 Take the 400 to a good machine shop and have the motor checked. (If you live around ILL or MO I know a few) With the last shop dropping the ball this badly, how do you know if they did anything right?  $1300 should easily cover any need block work to get the compression you are looking for.

Main thing I would wonder and worry about is if the deck height is correct! Maw Mopar was really bad about it.  It effect everything and is why BB run like there legend, or are road kill. For more details on deck height start a new post and we will fill you in. 

2 If the motor is in the car, drive it first before you throw money at it! A real 300 HP is fun. Then if it is still as not much fun as you want you can start playing around with new parts.

Main thing is you need some thing solid to start with! Does not sound like you think you have that at this point. I sure cannot blame you either.

Great parts on a crap short block = wasted great parts on top of crap!

Cuda Ken

[heyoldguy]

Hey XH29N0G,

I just rebuilt my 400.  it took the guy 5 months to somewhat give me my specs.  I told him I wanted to push 400 horses out of it and that I wanted my compression at 9.5:1 minimum.  When he finally gave me some of the specs over the phone, it had 8.75:1 compression.  yes, it's better that the advertised 8:1 compression (most 400's really had compression ratio's in the 7's), but it's not what I wanted.  I believe the lower compression ratio limits me to extreme mild cams.  I told him to work the heads and he didn't touch them.  So now I have a 400 with the following:

400 block
.30 overbore
10 bearing
hypereutectic pistons
mild cam  272/454 .272/.454
compression 8.7:1
stock heads
edlebrock performer RPM dual plane high rise intake
Holley 750 double pumper
headers
flow masters
2700 rpm stall
373 drive ratio

I don't know if I'm going to be happy with it.  The tranny went out 20 miles after the engine was installed and I got laid off shortly after.  I think I'm only going to pull 300 horses at best.  Once I get the tranny repaired and finish breaking in the engine, i'm gonna have it Dyno'd.  Who knows, maybe it will perform better than I expect it will, but this is why I'm considering the Edelbrock heads

Which casting number stock heads? Any port or valve work? What are the combustion chamber cc's? 8.7 is wan't you wanted, I understand, but it won't limit you to an exremely mild cam. A bigger cam will work better than a small cam even with lower compression but more compression would be even better. I do not recommend this, but we swapped to a 509 cam in a 7.5:1 compression 440 from a cam about the size you are using and gained 40+ horsepower. Then we put on iron heads, something about equal the to flow of the E-Street and gained another 50+ HP. Still at 7.85:1 compression.

All is not lost with what you have. Do as has been suggested, drive it first and see if you are satisfied. then consider changes.

[1974dodgecharger]

Wow oldguy and they say 509 cams suck that and itz too old of technology grind.

[heyoldguy]

This documents our tests with a low compression 440.

http://www.forabodiesonly.com/mopar/showthread.php?t=249866

[1974dodgecharger]

Good inf9 old guy now I d9nt feel so bad with my 509 lol.....

[firefighter3931]

Hey XH29N0G,

I just rebuilt my 400.  it took the guy 5 months to somewhat give me my specs.  I told him I wanted to push 400 horses out of it and that I wanted my compression at 9.5:1 minimum.  When he finally gave me some of the specs over the phone, it had 8.75:1 compression.  yes, it's better that the advertised 8:1 compression (most 400's really had compression ratio's in the 7's), but it's not what I wanted.  I believe the lower compression ratio limits me to extreme mild cams.  I told him to work the heads and he didn't touch them.  So now I have a 400 with the following:

400 block
.30 overbore
10 bearing
hypereutectic pistons
mild cam  272/454 .272/.454
compression 8.7:1
stock heads
edlebrock performer RPM dual plane high rise intake
Holley 750 double pumper
headers
flow masters
2700 rpm stall
373 drive ratio

I don't know if I'm going to be happy with it.  The tranny went out 20 miles after the engine was installed and I got laid off shortly after.  I think I'm only going to pull 300 horses at best.  Once I get the tranny repaired and finish breaking in the engine, i'm gonna have it Dyno'd.  Who knows, maybe it will perform better than I expect it will, but this is why I'm considering the Edelbrock heads

Looking at your build I can surmise that the low static compression ratio is a result of the overly large combustion chamber volume on the factory heads. Most that i've checked out were 90-92cc and that is a compression killer without the right piston. 

The E-Street heads are designed specifically for guys in this particular scenario. The small 75cc closed chamber will provide a nice increase in static compression while providing better quench (detonation resistance) while significantly increasing power through improved flow. There is no downside to using this head on a handicapped build as outlined above. 

Are your pistons a flat top design ? Part number ? What was the piston to deck clearance ?



Ron

[BSB67]

Hey XH29N0G,

I just rebuilt my 400.  it took the guy 5 months to somewhat give me my specs.  I told him I wanted to push 400 horses out of it and that I wanted my compression at 9.5:1 minimum.  When he finally gave me some of the specs over the phone, it had 8.75:1 compression.  yes, it's better that the advertised 8:1 compression (most 400's really had compression ratio's in the 7's), but it's not what I wanted.  I believe the lower compression ratio limits me to extreme mild cams.  I told him to work the heads and he didn't touch them.  So now I have a 400 with the following:

400 block
.30 overbore
10 bearing
hypereutectic pistons
mild cam  272/454 .272/.454
compression 8.7:1
stock heads
edlebrock performer RPM dual plane high rise intake
Holley 750 double pumper
headers
flow masters
2700 rpm stall
373 drive ratio

I don't know if I'm going to be happy with it.  The tranny went out 20 miles after the engine was installed and I got laid off shortly after.  I think I'm only going to pull 300 horses at best.  Once I get the tranny repaired and finish breaking in the engine, i'm gonna have it Dyno'd.  Who knows, maybe it will perform better than I expect it will, but this is why I'm considering the Edelbrock heads

Looking at your build I can surmise that the low static compression ratio is a result of the overly large combustion chamber volume on the factory heads. Most that i've checked out were 90-92cc and that is a compression killer without the right piston. 

The E-Street heads are designed specifically for guys in this particular scenario. The small 75cc closed chamber will provide a nice increase in static compression while providing better quench (detonation resistance) while significantly increasing power through improved flow. There is no downside to using this head on a handicapped build as outlined above. 

Are your pistons a flat top design ? Part number ? What was the piston to deck clearance ?

Ron

Like Ron said, the E-Street was intended for your situation.  Better compression and better flow with one check.

But, the dyno should have nothing to do with you being happy or satisfied with your build.  Your intention for the dyno should be to help focus your tuning efforts to get the max from what you have.  Have fun at the dyno and with the car.  If the power when driving the car is less than desired (and lets face it, it always is) start making plans for your next change, but don't worry about the numbers.