I have a set of pre-Edelbrock made MP aluminum Hemi heads in the shop.
They’re going to be used on a stroker build going in a clone car with exhaust manifolds.

The builder wanted it to have decent power, and the original plan(prior to seeing the heads) was just a valve job and bowl blend.
I mean...... they’re Hemi heads....... should be pretty good, right?

Well, after taking them apart and cleaning them up(used heads), and seeing/feeling how rough the interior walls of the ports were...... the decision was made to just “smooth out” the walls and trim down the guide bosses a bit, along with opening what ended up being rather small bowls, and recutting the seats.

If the flow numbers are any indication....... it definitely seemed to be worth the effort...... especially considering that it’s only getting a mid-.500 lift cam.

Here’s the ootb flow: 28” test pressure, 2.25” flow tube on exhaust

Lift ———in/ex
.100 —— 83/58
.200 ——160/136
.300 ——232/195
.400 ——276/221
.500 ——294/225
.550 ——299/226
.600 ——303/226
.650 ——305/226
.700 ——307/226
.750 ——309/226


Here’s how they looked from MP:

Waiting for the 400+ numbers.

First step was recutting the valve seats, along with a bowl cut for the intake side.
Starting with the intake side, I blended away the ridge that was left from the factory bowl cut, and opened the intake bowl enough to have a smooth transition into the port walls, and then trimmed away a good portion of the rather chunky guide boss.
Then smoothed out that work with an old dull carbide. No eye candy sanding rolls for this job.
The two walls, the roof and the floor really didn’t get “opened up” at all. I just ground away the rough casting surface, and finished it off with the dull carbide.
There was a noticeable step where the seat insert met the floor at the SSR, and I made sure that was a nice smooth transition, and made the SSR itself slightly more gradual.

A very similar situation went on with the exhaust port, only more time was spent trying to improve the SSR, since it’s pretty abrupt as it comes as cast.

The fresh VJ and porting yielded these results:
(These are nothing all that fantastic for Hemi heads, but it was a very nice gain (imo), with a pretty modest gain in runner size)

Lift——-—in/ex
.100 —— 80/57
.200 ——166/132
.300 ——237/202
.400 ——310/253
.500 ——351/257
.550 ——357/262
.600 ——355/264
.650 ——357/266
.700 ——359/268
.750 ——361/270

Where these Canfield castings or another brand?

Here’s a pic of the foundry mark...... maybe if Zippy sees this thread he can shed a little light on where these were made and about how old they might be.

Also a close up of the port wall texture(they actually “feel” pretty smooth)

Very nice gain for the work done! Just goes to show that there is rarely anything ready to run out of the box and that looks like typical MP quality. Nice catch and save Dwayne, I bet the owner will be happy!

Yea, out of the box he was set to get stomped by seemingly lesser motors.

That is AWESOME !!!! Thanks for sharing Dwayne

I’m sure there were numerous 528” MP crate Hemis built with heads that were just like these.

Reworked like these are, and then step up from the MP 292 hyd cam to a nice suitable SFT cam....... I bet the difference in power would be pretty substantial.

That would make for a fun dyno test.

Its funny you mentioned that, there is id call it like a pro street cuda in the hood here with a big MP crate hemi, hes never beat my small block stroker street racer, or many others really, im probably 2.5 seconds quicker in the 1/4 but he has knocked the main bearings out of the bottom end trying.

I should ask if he ever looked at his heads?

Hes been beat so much hes not brought it out in a year and a half. It just sits.

Dwayne I agree, it should really make much better power, at 1st when I read how much improvement you made without EXTENSIVE work it reminded me of some old Merlin BBC iron heads I worked on when I was 1st starting out doing port work, basic bowl clean up, Valve job & I got about the same results of improvement as you did on the Hemi heads, I was so exited, I was bragging to my boss & he then asked me,,, Did you forget to put a spark plug in that cyl for the test,,, well, you know the answer LOL OOOPSS

Very Nice !....have you ever thought about doing this for a living

Another before/after shot:

That looks great, those heads sure looked like crap before, are these going to be dyno tested when you are done ?

Looks like MP was trying to duplicate the burr finish that some of the head porters use these days?

I’m not building the motor, but I believe that plan is to dyno it.
It’s going in a driver with ex manifolds, so the cam is pretty tame.
I’m pretty sure it’ll be running the stock type intake manifold.

I really have no feel for what it’ll make in that configuration........ other than, not as much as it could.

They sure felt more like the gravel in my driveway than any type of burr finish.

Even the coarse non-ferrous burrs I was using to rough in the ports left a smoother feeling finish that how these were as cast.

The odd part is....... the roughness was really confined to the inside of the ports.
The exterior of the heads is much smoother.

I’m pretty sure the 58cfm gain at .550 lift will pay some dividends.

I could never figure out the foundry those 110-Ms came from. I tried like heck to find the RC marking on other parts and failed. Maybe someone who knows casting really well would be able to identify that. At the time I wasn't trained on the Reynolds and Reynolds/RUMBA green screens to find all the suppliers, and depended on other folks to look that info up.

In normal old world MP fashion (using basically the same logic as paint marks which usually failed to identify cams) they weren't date coded. The only indication of a rough date of manufacture was on the box, or the yellow sticker on the crate engine they came on.

I do know the 110-Ms actually had two machine shops at the end of their run, which I thought was weird.
Cummins recon did their machining in-house for crate engines, and the parts heads had somewhere else.
Say what you will about Cummins recon (And you would be right), but the seats pretty much never fell out of crate engine heads. I can't defend them as they had other issues besides that, but they did get that one detail right.
If anyone is lucky enough to have never heard of this rightfully earned folklore, you're very fortunate to have not wasted any time on it LOL.

When 110-M's were phased out I hoarded a few sets, some with more issues than others.
Some are in beautiful shape, some have issues that required welding, and I bet you can guess the rest.
I didn't use them and went with Victor Jr instead, this thread helps explain some of the reasons why LOL.
That stuff I collected will probably get sold cheap to someone local.

You know, I am going to act like an old guy and point at history for a minute.
I'm pretty sure 300cfm @ .600 was probably considered outrageous and amazing airflow....................in 1964.
From that perspective, they kinda do what they are supposed to do.
They're like a stock replacement head in aluminum, sort of.
Well, the iron heads were never that ugly but I'm talking from a functional standpoint.

From a modern perspective,110-Ms basically HAVE TO be ported and well prepped... preferably by a pro...to stand a chance at keeping up. Having Porter Racing heads go through them was definitely a good move.

Zippy, I had the understanding that the latest aluminum heads sold by MP with standard valve sizes were “fixed”, meaning they had no issues as the earlier ones did. Date codes on the packages were around 2012-2014 I think. Have you heard this or not so?