[PDC]

I found this thread of a build that Paul Carter did for a client who wanted the 703 in an iron D-port Head 455. The results were impressive.

http://forums.maxperformanceinc.com/...d.php?t=776169

Although the Round Port E-Heads could certainly make good use of more cam, I can’t help but believe you’d get better numbers than iron D-ports with the 703.

Think of the now tired ‘Junker to Thumper’ article: boneyard, non-rebuilt motor made 390 hp with unported 7k3 castings and power jumped to 440hp with a pair of original style bathtub chamber 87cc round port E-Heads ... using the much maligned XE-274. I know that article is a lightning rod on this forum, but I do think it provides a decent indication of how the E-Heads will generally make the most of whatever your cam can feed them.

Point is, if I had a brand new 703 on the shelf and was pressed for time and parts availability, I wouldn’t hesitate to use it.

[Steve C.]

Down the road if your considering a change in valve springs keep in mind when the talk rolls around to minimum pressure requirements for a specific cam, That minimum might be when the springs have lost a bit of pressure after run in, as they often do.

Example the Comp 986 spring is a popular choice that will fit Edelbrock heads, rated 132 lbs at 1.800". A real world example, years ago Ken Crocie did a nice engine build and he used that spring. The pressure was set at an initial setting of 130 pounds on the seat, with 320 pounds open pressure. Knowing the pressure would ease down toward the rated value. The actual pressure after a day on the dyno was 122 pounds. After run in it lost 8 pounds seat pressure.


.

[glhs#116]

OK. So since I have one of my heads (the other is still on the way) I thought I would start documenting some of the sorts of things I would have been interested in seeing. My heads are the 87cc CNC chamber heads. My factory heads are 1971 197 HO heads.

Here's the chamber versus head gasket view for each:
Factory 197


Edelbrock 87cc CNC


Sorry for the sideways pics. The only easy way to do this was with the heads standing on end.. Looks like PY forums doesn't see the "rotation" metadata..

Sam

[glhs#116]

OK. So here's the intake and exhaust ports also versus gaskets..

Factory 197 intake


Edelbrock 87cc CNC intake


Factory 197


Edelbrock 87cc CNC


Crazy how much smaller those Edelbrock exhaust ports are. And there's a stern note in the box telling you not to try to make it bigger..

Sam

[glhs#116]

Here's one chamber with head gasket close up.

Factory 197 chamber


Edelbrock 87cc CNC chamber


On the exhaust side of the CNC chamber there is a bit of an undercut. This leaves a slightly sharp edge. Should I be trying to smooth this off or leave it?

Sam

[glhs#116]

I was kind of interested in the extra money the factory spends that the aftermarket doesn't. For one thing, no freeze plugs. For another thing, Edelbrock don't bother with that little bevel that lets you stick the intake gasket in place using the little coloured plastic buttons.

But the bit difference I could see was the huge factory oil drainback channels being replaced by four small holes. Do these heads really drain back oil sufficiently? The view of the massive factory drainback channels is a bit hidden in these pictures by the pushrod plates but anyone who has seen one in person knows what I mean..

Factory 197 overhead view


Edelbrock 87cc CNC chamber overhead view


On the other hand, Edelbrock obviously continue to evolve their product. In the box the card warns that valve cover bolts need sealant because the bolt holes protrude into the intak ports. On my head, all those holds are blind. A relief, really.

Sam

[steve25]

I posted about a drain hole mod for these heads, but I forgot about your need to now have atleast one 1/2" pipe plug to close off the driver's side hole at the end of the head, and really in the heat where you live you can plug off both sides since you do not at this time need a nipple for the heater hose to the fire wall.

Also do a double check and make sure none of Intake Manifold side valve cover bolt holes break into the roof of the Intake ports, if so it's sealer time on the bolt or stud your using.

Also it's critical with Aluminum heads to lube up the head bolt pad well to get a clean torque reading.

[grivera]

Nice comparison! BTW, my JBP e-heads came with the 1/2" pipe plugs. Do the round ports not come with the plugs?

[Steve C.]

The Edelbrock specs state the heads have a 1.800" installed height. Using Crower 68405 springs at that specific installed height will result in only 76 lbs seat pressure according to the chart:

https://www.crower.com/catalogs?id=valvesprings


Not a good choice.


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[azbirds]

While you have it apart drill the hole in the block above the center exhaust side bolt hole. It is nice that the E heads have that hole in them. I know that mod sure helps keep in cooler in Phoenix.

[Skip Fix]

Originally Posted by azbirds

While you have it apart drill the hole in the block above the center exhaust side bolt hole. It is nice that the E heads have that hole in them. I know that mod sure helps keep in cooler in Phoenix.

X2 Even did it on the IA block.

[glhs#116]

Gents, drilling up a block is pretty serious business.. What are we talking about? This?




And if I were to drill a hole straight through the deck here centered in the gasket hole how big a hole are we talking? 3/8"?

Sam

[darbikrash]

Originally Posted by steve25

Also it's critical with Aluminum heads to lube up the head bolt pad well to get a clean torque reading.

I'm curious about this. ARP head bolts use hardened washers which should not turn when you torque the fastener. The surface between the bottom of the head bolt flange and the top of the washer should have lots of lubricant to encourage the fastener to rotate freely against the washer when torqueing. The joint between the bottom of the washer and the aluminum seat pocket should not be lubricated as you do not want this washer to spin?

Same as main caps?

[adynes]

Originally Posted by darbikrash

I'm curious about this. ARP head bolts use hardened washers which should not turn when you torque the fastener. The surface between the bottom of the head bolt flange and the top of the washer should have lots of lubricant to encourage the fastener to rotate freely against the washer when torqueing. The joint between the bottom of the washer and the aluminum seat pocket should not be lubricated as you do not want this washer to spin?

Same as main caps?

Yeah, I think ARP recommends NOT to lube between the washer and cylinder head, for risk of over torquing and pulling threads. I'll see if I can find that article again...

Might not be as big a deal on Pontiacs though, as I (and I'm sure many others) have done it in the past without issue. But, I won't be doing it anymore.

[adynes]

Here it is:

https://www.dragzine.com/tech-storie...ng-head-bolts/

[steve25]

Sam, Something is a Miss with those spark plugs, as the unthreaded end lenght is like 1/4' too short!

My post about the lube thing is from seing that many folks even these days will still use head bolts with out washers.

I drill in those added cooling holes every time!

I start the hole then just roll the motor over on the stand almost 180 so that drill the hole sends all the drillings out on the floor and not in the block.

[glhs#116]

Autolite 3923. They claim to be the correct spec..

Sam

["QUICK-SILVER"]

Originally Posted by glhs#116

And if I were to drill a hole straight through the deck here centered in the gasket hole how big a hole are we talking? 3/8"?

Sam

No bigger than the hole in the head. And it doesn't have to be that big.
1/4" should be more than enough. Even with the two big holes closer to the outside...Between those two exhaust valves is hottest spot on the head.

You don't want the hole so big that it changes how much coolant goes to the back of the head. Unless you're doing balanced four corner water return to the front crossover.

Clay

[Skip Fix]

And you can use the head gasket as a template. If the short block is together masking tape off both adjacent cylinders and have a buddy with a shop vac while you drill.

I guess another question for ARP is when did they improve their bolt and washer finish? And is there a "date code" on the boxes they come in? Bet alot are previous rougher bolt heads.

[MarkS57]

Originally Posted by adynes

Yeah, I think ARP recommends NOT to lube between the washer and cylinder head, for risk of over torquing and pulling threads. I'll see if I can find that article again...

Might not be as big a deal on Pontiacs though, as I (and I'm sure many others) have done it in the past without issue. But, I won't be doing it anymore.

I just went through this Friday night. ARP instructions has you putting the lube between the bolt head, washer & cylinder head and on the threads. I found the whole experience a little nerve racking. I went 40 - 60 - 80 - 100 ft-lbs. I was sweating that last pull 80 - 100 waiting for the 45 year old block threads to pop. None did thankfully.

When using stock head bolts and iron heads, I'm pretty certain the tension on the block threads was never as high as the ARP's are with the washers and the supplied lube.