Hey matt.

The head guy I used is Mike Haley, at Hi-Flow heads in Alsip, IL. Mike is a super guy. He does heads, and thats it, since early 90s. Extremely anal, honest, and pretty good timeframe. He answers the phone, and always willing to discuss your needs, etc.

When I first brought him my old dart heads, he inspected them thoroughly. He had me come to the shop, to actually show me what was done incorrectly to them, and what would need to be done to correct them. Many shops will tell you this or that, and expect you to take your word on it, but Mike actually shows you.

I mentioned these EQ castings to him. At first he seemed skeptical. When I mentioned that they were supposed to be the same castings as the RHS/Pro Topline, he seemed more curious about them, as he had worked with those in the past. Anyhow , i orded two sets of them, and brought them to mike. He immediately began looking them over, and liked what he saw with them.

We started doing flow tests. We flowed the darts I had, and had a baseline. Mike started doing some mods to the EQ heads. He adjusted the throat diameter, ported the chambers, did a nice valve job, etc. The exhaust flow was a little weak he felt, so he did a little cleanup there, and the exhaust improved.

Overall, right out of the box, they outflowed my old darts. I could have stopped there, and been fine. The goal was to get the flow numbers from .100 to .650ish up. The port was flowing pretty good at 600-700 out of the box. The low lift flow was what we were looking for.

As for setup, mike checked each and every valvespring for pressure and coil bind . Each valve gets micd for install height check. Unlike the last shop that did my heads, and had major variance in install heights, spring pressures all over the place, wrong hardware with springs, etc. You will not get that kind of work from Mike at Hi-flow.

I was not too concerned over the iron head thing with a supercharger. Mercury marine did it for years, and many many have supercharged stock mercury engines, with iron heads, and had zero issues. I do like the fact, iron is more resistant to corrosion, expands at the same rate as the block, and head gasket brinelling is really not an issue. Everyone has their own opinion on that topic though. As far as the weigh gain, that obviously didnt hurt me. Matter of fact, maybe it helped. My boat likes bow lift, maybe the extra weight in the stern is helping . Who knows

It's so easy to measure one intake and exhaust and then set the rest up the same.. And that's where you get into trouble.

For example; I was adjusting installed height on a set of heads for a customer this summer and out of 16 one was way out... After scratching my head for a moment and thinking the machine work to the spring cups were machined incorrect, I pulled the intake valve out and measured it up against the rest of the intake valves and figured out that the one valve was shorter then the rest. I put a new valve in it so they were all the same but if it went unchecked it could have surely meant disaster for this high dollar engine!

Panther, how did you end up making out on those 502 MPI you did with the EQ heads? A buddy was thinking about them for his 502 mags

The combo I built netted him roughly a 10mph +/- gain. He put a lot of hours on them this year and was really happy with everything.

Fly by: https://youtu.be/r2QiV9bHmU4

Idle: https://youtu.be/bzhqoP7eIAc

Awesome. Not just on the heads, but the whole builds.

Thank you

Hey guys I'm thinking about using ch454a heads on an 502 Mag I'm freshening up. Could anyone comment on the exhaust valve length there using, spec sheet recommends a +.100 valve. Thanks

Ferrea 1261P super alloy is what i am using


http://ferrea.carshopinc.com/product...63828/F1261P-8

Mild Thunder did you use std length for the intake also.

Those are +.100 exhaust valves. I forget which # i used for intake, but they are +.250 if i recall.

Pretty sure Ferea1232p was intake.

Thanks for the info.....

Hard to beat the performance and value of these heads. For 900 a set bare shipped to your door, vs 2600 a set for a set of afr's bare, hard to beat. And the afrs certainly dont perform 3x as good , or last 3x as long

I am seriously considering them also. I have heard nothing but good on EQ. My only concern was limiting cam choice. Since I decided on building NA for time being I need every edge I can get.

This might sound like a joke but any one have the balls to try a set of the promaxx that use to be patriot but now under new name and ownership I believe and foundry as well. I've read some articles on them where individuals were dissing them however they never owned a set. The positive feedback I've read are from individuals that actually are using the heads and like EQs don't take much to get decent numbers out of them.

But ya MT having two engines to consider the price gets pretty expensive when you go the high end brand name heads especially after there loaded up with all the good guy valves and parts.

I'd rather have a little less of a head and put the extra monies of what goes in it as well as machine work and getting set up 100% correct.

I just saw on Facebook, where someone was offering a CNC program on those promaxx heads. I believe they are offered in 320 and 360 cc as well.

That was my thoughts on the EQ heads. I am not looking to bolt on any brand head out of the box. So, whatever head I would purchase, is going to the machinist.

Lets say, you save 1700 bucks on a pair of heads . Thats 1700 you can use towards GOOD hardware, not some entry level springs, made to fit a variety of cam profiles. You can have the guides properly sized, some cleanup work done, or whatever. In the end, I feel you will simply have a better product for the same or less money.

Of course, there are some downsides. Dart, AFR, Brodix, offer a much greater selection of port sizes. I know alot of guys don't like iron, because they fear it will cause detonation, or sink their boat with all the extra weight.

I don't think power level is really an issue with the EQ heads. In the right hands, there are plenty of guys making 800, 900, 1000hp on motor with them in truck pull classes mandating iron heads. Of course these arent pump gas 5500rpm engines, but you know what I mean. Also, Quite a few guys are now offering CNC programs for them , flowing well over 400 cfm when ported. Chad Spier, Eric Weingartner, High Velocity heads in tennesse, and some others have CNC programs. Hell, Eric's CNC ported versions of them, he gets 2450 a pair bare. Flow 460 CFM he claims. Of course, they are no longer 320cc runners though after his cnc program.

I've heard good things about the new Promaxxx so far. A very reputable machine shop I use and trust just became a dealer. A friend of mine got a set of their full CNC through this shop to put on his 565 with an 8-71 blower. I am considering the 320 cc version myself. Should see some dyno numbers hopefully soon on that one. I have another friend who is probably going to use them on his 600SC refresh/pump up. That should be interesting too. I will post more when I hear more. So far reports I've heard from the one friend and the shop who is a dealer is that quality is very nice and so is the machine work. Thick decks too.

getrdunn - why would the EQ's limit your cam choice ?

i am gathering parts to build a 509.i bought a set of the eq 320,s that i am having a cnc valve job done on them,no port work .i got joe,s old inconel valves from his old heads and a set of manley severe duty ss intake valves.also have a set of 2618 forged pistons that will give me 10.1 to1 c/r.i am going to use a 525 efi cam and see what kind of power it makes,looking to spin it to 6000 rpm.i am looking for 625 but won,t be suprised if it does a little better.i won,t have time to complete this project untill late spring but when it is done i will post the results.

Very interested to see results of this!

Somehow I knew I'd here this from you and I think you know the answer. A point less in compression will limit cam choices due to valve timing etc. Iron 9.5 and aluminum 10.5 max on this heavy boat but at least has effficient bottom.

You ever install a cam in an engine that requires 11:1 static comp in an 9.3:1. Valve timing on cams I've got lined up are all 10.5:1 - 11:1. Back in the day I had friends who wanted the king of the drive in cam in their muscle cars so they and had an awesome ratty azz idle but ran like turds.

I was looking at the promaxx 2211's but it says they are limited to .600 lift. and I plan on a 731 cam which is .610

For a boat engine? 10:1. Or something else?

Buy bare

I would get non cnc'd and make valako work hard. Yup I alaways get bare heads and do what I can port wise and off to shop they go for detail porting/blending. Will be interesting to compare cnc to hand porting results. Getting 320's either route I go but have narrowed down anyway.

I think there are far more things in an engine build, that can induce detonation, than simply the cylinder head material.

They told me I couldnt run boost with an iron head. They told me I couldnt run much timing. Because iron heads , don't dissapate the heat as well. 9lbs and 35* deg total, and no issues yet.

Only one season so far with them, but probably 15 or so wot runs like this. If she was gonna melt something, crack spark plugs, or anything like that, it prob would have happened by now. It doesnt take long at the 1.75hp per ci level. https://www.youtube.com/watch?v=DtWGMAdeKbU

it should work in a car or a boat.i don,t have any plan for this one and will no doubt sell it sooner or later.

If it wasn't for guys like JimV, there would be no cnc programs. :)

Dammit. I had to go and post that video. Now I miss my boat. Is it spring yet?

Racially profiled comments will get you no where here. :lolhit:

Your engines no doubt educated yourself and others. Like BB says if you don't push the limits a little from time to time and keep up with the same o same o you never advance or gain performance or knowledge. MT how your plugs look after those hard runs. Also you ever use a bore scope to get a visual of upper land. Any signs of hot spots or signs of breaking down near the exhaust. Just curious. I gotta give you credit. You've obviously got them tuned perfectly. That's the key for sure.

Thumbs up. That's good power for 468/420 on pump gas.

Geterdunn - you also have to remember, which all of us need to remember, that alot of the compression and a/f 'safe' ratios and 'safe timing' settings where set before modern combustion chambers, wide band's, and etc.

Plus most, not all, boats being set up to run as much cold water as possible thru the engine provides a lot cooler head temperatures than those running arm/hot water back thru the block.

Jim just returned my call. I'm gonna have a set drop shipped and will keep you posted on results. I think flow will fall in line with worked over EQ's, Profilers, darts, afr's etc with the 320 runners. My biggest concern is valve seats which is ductile iron I'm pretty sure as well as all the right holes in the right places and angles.

I will be on the maintenance program big time first 50 hrs especially paying close attention to the seats getting hammered up in the heads.

So what heads are you going with?

Promaxx 320's starboard side and EQ's port side. Will help weight distribution when running solo... Jim wants to play with the promaxx and see what he can do. Evidently he's pretty impressed with the casting but not much or any seat time with them but wanting to give them a shot.

How about 332's. :)

Jim ordered today. Done thinking about it. To much other chit going on in my life right now. I think about engine builds etc about like a kid looking forward to his first remote control car or mini bike. Well now maybe iPads or Xbox.

Anyway it's done. Now it's up to Jim to work his magic.

They'll end up about there if I had to guess. Hah

So once somebody gets a look at the promax 320's, what would be the likely difference on a 454, 8.5 comp, 731 cam and 525sc blower?

And being alum, if the comp stays at 8.5 with 5 psi boost, would one be able to use lower octane fuel??

Jim V just finished 2 sets of eq320s for my 525sc rebuild. Here is the flow numbers with just a bowl port.
.2 148 151
.3 223 201
.4 295 240
.5 340 273
.6 375 289
.65 387 292
.7 391 295

Chamber was 122c.
Pretty decent numbers.

Awesome!