My Son Matt sold his .040 over 360 shortblock out of his Duster a couple of months ago to a Friend. Needing a set of heads for it I have been researching ways for him to get the engine assembled and into a Dart that he recently bought. Knowing the Procomps (Speedmaster) had some issues I tried to find some info on the ProMaxx small block head that Jegs sells. With springs good for up to a 575 lift cam they cost slightly over 1400.00 a set shipped, app 200 plus dollars cheaper than Edelbrocks. I told him if he bought a set I would flow test them on my bench and strip on down to check it out for free. So far I have nothing but GOOD news for these heads and they put the Edelbrock heads to shame in both quality and flow numbers. The only issue I see so far is that the exhaust port flows almost EXACTLY the same as the Edelbrock head and they both have terrible (slow) air-speed on the exhaust side. He is going to install these as delivered so I can't wait to see the results. Air-speed at .500 lift on the exhaust port maxed out at 175-180 FPS and I good exhaust port should be at least 325 FPS and needs bell-shaped to get there. Both exhaust ports maxed out around 182-185 CFM and were checked without a ex flow pipe

-----Edelbrock--------------ProMaxx
--------Intake-----------------intake
.200-----128--------------------129
.300-----182--------------------184
.400-----215--------------------235
.450-----226--------------------251
.500-----233--------------------255-260 high air-speed
.550-----236--------------------260
.600-----242--------------------264
.650-----243--------------------270
.700-----243--------------------263-270
.750----------------------------263-270

As you can see by the numbers this BOTH ports need more volume. The air speed on the ProMaxx at the pinch at .400 lift is 300 average (center) at the pinch and 370 on the pinch turn. At .400 lift 365 FPS-390 FPS on the short-turn. At .500 lift at the pinch center 340-350 FPS and 401 FPS (pegged my gauge) at the pinch turn. At .500 the short-turn is way high at 390-401 FPS (pegged).
So far 4 valves were removed and the valve guide clearance is GREAT and a very nice at least 4 angle valve job done. The stainless valves look nice and come with a 30 degree backcut. I will be buying a couple sets of these later this year. One set with stock 2.02 valves and one set bare so I can go with a 2.08 valve

thanks for posting this info!

Monte said the Promaxx guys have nice equipment and know how to use it, which really makes me tempted to get some big block Promaxx heads for a hot street build and save some cash over the Trick Flow heads.

Some pictures

More

He are some Edelbrocks that I bought last year. This is one I have preped for a 2.08 valve so the valve job is NOT from Edelbrock. Their quality control is really going down-hill

Good info John, I think by the lack of replies it shows the mopar world here is still reluctant to embrace the offshore castings even when looked at from a decent company with decent qc.

If this were 25 years ago or better most would think the top pics were the usa cast headand the lower being the china junk.

I know your all about buy usa but what can ya do when it seems edelbrock takes so much for granted or simply just dont care.


Would you trust this company and quality of parts to run every set ootb, or would you still pull them down for inspection?

Thanks. Honestly I was starting to think it wasn't worth the effort even posting results or findings anymore. Fat guys are more worried about installing aluminum bolts to go faster. Lol

I am never going to install an out of the box head on any of my builds. A good friend bought a set of AFR chevy heads that were then sent out for some cnc porting. The flow numbers provided were 20 cfm low and the air speed was out of control. 2 valve guides were so tight I know for a fact he would have had issues. I was very glad he was at my shop to witness this. Some guys think all CNC'd heads are the same but trust me they aren't. I sure hope more of today's kids take an interest or years from now I see problems. Someone's gotta get dirty

Those are some pretty good numbers as-cast. What sort of rocker gear do they take?
What size valve stem?

Do the ProMaxx heads come with heli-coil style thread inserts?

They are nice looking heads, for sure. Thanks for posting.

Vey Interesting and useful info.

What's very telling is the ~20 to 25CFM OOTB difference from .400 through .600 is going to be worth roughly 40HP or more to a combination with enough cam and compression to take advantage of it, that's a VERY SUBSTANTIAL difference.

The Story Bryce Mulvey (yes I am aware of the horror Show) told was that Procomp sent their Eddy clones to DrJ's/Airwolf for testing and they suggesting some mods to the roof and the next batch would outflow the Eddies. Full disclosure, my 414 motor has the Airwolf SBM (using Steve Dulcich's 408" shortblock) heads from the magazine article.

That's what I liked too. I'm thinking that with very little work these heads would go 280 plus and I mean very little. Bell shape the exhaust port to get some speed and let her breath.

Looks like they did a better job of the port entrance/exit than they did with the BB head.

I am a little puzzled why they cost $320 more than the BB heads though.

If you open the exhaust exit, won't it be out beyond the size of most headers?

I don't know if it's just the pics or what, but the roof of the intake port, adjacent to the guide boss, looks much more "normal" than the Edelbrock head.

The exhaust port kinda has a Herman Munster forehead on the exhaust short-side and needs widened some and shaping. Like I said on these its all free checking for a Friend to get him up and running so the grinder won't be touching these. It will be a good test. On my car I will make the exit however I deem necessary because my headers (1 7/8 hedmen) have already been modified. The headers on my Duster are W2 headers with adaptors.

What have you gotten out of an rpm head(intake port),and what was the runner volume when it was done?

I've never poured one after porting but I got 315-318 cfm with a 2.08 valve without moving the pushrod. Tubed but not moved and a lot of work. Bolt hole is also tubed but I do that on every Edelbrock head I port. K&S tubing makes it to easy not to. I won't be sonic checking the floor on this set but I'm betting they learned from Procomp (Speedmaster) to fill the floor some. From what I hear several guys approached Edelbrock about doing this and they didn't want bothered.

Some good info.


https://www.youtube.com/watch?v=hxLnEID_Xfc

Intake port cut-away

https://www.youtube.com/watch?v=BZzudIxHY0g

Combustion chamber


https://www.youtube.com/watch?v=4op2k_k301E

That 315+ is way way more than I've gotten out of them. But, I'm usually going for the no-holes-no-tubes plan.
I think low 280's is the best I've gotten out of a basic porting job, 2.055 valve.
Those made 589hp on a 419.

This project was for a very good Friend that does my transmission work and it became a challenge project for me. They started out with me repairing a set of 400 dollar open chamber Edelbrock (340) style that I repaired then added a 2.05 valve. He was then curious how much we could get out of a 2.08 valve so I tried it. Without moving the pushrod I would NEVER do a set like this for anyone again, except for myself. A 2.05 is the way to go. He ended up never even using them and when he said he was going to sell them I bought them back because I had to much time in them to not have them. Being retired and not doing it for a living allows me to play around and I love flow testing and probing a port.

Edit

Ok, good info.

So the procomp is the same as speedmaster? I do not like what i have seen in the procomp stuff for brand x

The promaxx is different then those castings?

I was in the market for sb heads and found it very confusing

Did you watch the videos as they will answer a lot of your questions. This head is not even on the same page as the speedmaster (old procomp) and in my eyes so far is way superior than the Edelbrock.

Just to put this out there....not a reflection on the Promaxx stuff. But I would find someone that has real world experience with them from a durability standpoint. My buddy just dropped off his truck with a very nice 496 stroker BBC short block topped with offshore heads and the quality of the guides and valves wrecked the whole thing. I am talking about mushroomed valve stems to the keepers , a valve that dropped a head off with no prior evidence of touching anything, valve to piston was .270, and valve guides that are .030, yes .030, out of round.

The heads were very nice out of the box...I could not tell the metallurgical make up of the parts though.

the casting looks ok even after all the destruction......

Has anyone run these heads for any extended period of time?

And what kind of heads were these. Please don't tell me procomp speed masters because there is a crazy amount of info out there to stay away from those heads.

Those are the ProComp/ Speed Master Heads

Im in mexico. I will check them out when i get home

These were not Procomp/ Speedmasters............

Ok I always up for a good challange. I called and talked to PROMAXX in Alabama and Steven told be these are not Procomp (speedmaster) heads. 100 percent of the machining is done in house. So from this point on all the naysayers PLEASE start your own post and post any results YOU find. No wonder guys that used to pass tech on this site are in hiding and no longer post.

PROMAXX


http://www.promaxxperformance.com/index.php/racing-parts/sbc.html


PROMAXX (Speedmaster)

https://speedmaster79.com/contacts/

If you go to the speedmaster website, it says that procomp is the sole US distributor for speedmaster.
So speedmaster is procomp.

I can't speak about the SB mopar heads, but when the Sidewinder BB heads were first being talked about, one of the owners of the foundry in china confirmed that at least for the BB Mopar head that it was the same head as the ProMaxx head.

I just received a set of speedmaster BB mopar heads, and I can see no difference between these and the Sidewinder heads. They even came in the same looking box.

My guess is, the speedmaster/procomp/ProMaxx SB mopar head is all the same casting.

Watch the videos on the valve guides. procomp like I said changed their name to Speedmaster because of poor reviews. They are sold right of the ship from China like all the junk electrical products. ProMaxx too recieves them off the ship from Chine as a rare casting then machined in-house adding to the price of the Speedmaster product. I'm done.

I don't doubt the guides are better. When ProMaxx was Patriot they used to advertise that the guides were made and sized in the USA.

Edit- just checked one of my catalogs for ProMaxx, says all heads come with USA made guides.

Edit

Edit

to Bad our Promaxx heads didn't stand a few mile in a Little red....
a valve spring broke in 3 pieces and dropped a valve......

BUMMER.........

Can I see some pictures of the head PLEASE. Front, back, ex side, and intake side please.

edit

We have to pull the head first..right now the truck is behind the garage...

When we got the heads, casting looked pretty good...I was even impressed!

I bit discouraged so we parked it for the 2 weeks vacations...
Dan

A lot and I mean a lot of guys don't know what they have so yes I would like to see pictures from 4 angles. I will not buy a Speedmaster head (formerly PROCOMP) so I too am learning. Monte has spoken highly about ProMaxx heads before and being highly displeased with the quality of Edelbrock heads I started posting questions about the ProMaxx brand of heads. Probably 80-85% of racers entrust others to build their engines and don't know a Speedmaster from an Indy head if they held it in their hands. Like it says in the links I posted one place is in California and ProMaxx is in Alabama. Asking for pictures is a true way of getting quality information.

I would assume, from the pics you've posted, if the head with a dropped valve is a ProMaxx head, it's CNC'd right into the end of the head.

Maybe... all of these heads (Speedmaster, ProMaxx, Airwolf, etc.) could all be manufactured at the same factory or factories in China.
The head companies just place orders and have their name put on a box, or etched into the end of the head.


https://www.alibaba.com/product-detail/S...4857.0.0.wvmncJ

Same for the big block casting out there. I bought some PC vectors after speaking with Jeff at MCH. He advised that the castings were decent but to buy them bare and build them using good valves, springs, etc.

That would be my thought as well.

When given an reasonable option I will always put our own people to work..

with all that has been said so far, would/could it be possible to buy a set of heads that had problems real cheap, and rebuild them to some what acceptable standards using quality springs, retainers, guides, and seats, and have something usable on the low end of hp/torque for a reasonable/lower cost than spending big money up front ?[compared to rebuilding a set of iron heads]. this is just a rhetorical question. i'm guessing it would not be possible [unless a guy could do all the work necessary himself], but i'm asking because i will be needing heads in the future and pennies will be counted very closely. i understand also, a good,used pair of heads would be the way to go, but would still need disassembled and checked. just throwing this out there and hope not throwing the discussion way off track.

Well, Im right back to being confused

All I would add to that is consider the guides also....

To all of this, all I would like to know is has anyone run a set of these successfully for an extended period of time....If 1 person has then we know it can be done. I know the set in this post is in very good hands.
Wish that is all I would have said in my first post

this guy got a set of the bigblock 9440 promaxx heads...
i sent a PM a while back asking if he had any problems, never heard back.

https://board.moparts.org/ubbthreads/ubbt...tml#Post1799674

People can believe whatever they want to.......but I know for a FACT that ProMaxx heads are machined and assembled here in the states. Guess I should have taken a picture of the pallets of raw castings to prove it. So while it IS an offshore casting.....it is NOT a China machined and assembled head with ProMaxx etched on the end.

ProMaxx is owned by Jason Collins. Former IHRA Pro-Stock racer and also owns the track in Steele Alabama. He bought the company from Mart Witt. It started out as Alabama Cylinder head and they mostly did refurbishes on stock stuff. Marty worked for ACH and pushed the owner to get into performance stuff, which they did and renamed the company Patriot Performance. When owner retired, Marty bought company. He and Jason have always been close friends and when Marty wanted out, Jason bought it. Last time I was there, Marty was still running the shop, but not sure he still is. As I said before, they have state of the art equipment and guys who know how to run it.

To prove the quality of the castings, Marty ran his own heads on his twin turbo, big block Chevy, drag radial car. They were off the shelf water castings and he runs 50 lbs of boost. Car has been 4 teens on a radial

Good luck with that. You will not find a foundry here in the states willing to do it for you at a reasonable price. Reasonable price, demands you order a crazy amount of castings. How many small block Mopar heads you going to sell? Guys complain to high heaven if the head is a nickel higher than someone elses, so US foundry is out of the question.

Edelbrock can do it, because they OWN their foundry

Thank-you Monte. After calling them yesterday and talking to Steven I felt pretty comfortable dealing with this company.

Basically, they are offshore heads with USA assembly, sounds like. You can( and I did) throw great parts at W5 heads, but they were cast like feces. Ended up as sprinklers.

That said, no matter who cooks the steak, if the meat isn't any good, it's gonna taste like poo. That seems to be the question here, and at least regards the small block Mopar heads.... It appears to remain unanswered until somebody flogs them for a good spell if they will hold up.

Back to your regularly scheduled programming............

That was such a good post you had to say it twice. Lol. It comes down to some guys are happy running 12's, some 11's, some 10's, some 9's and some are always searching. I'm a budget racer that loves testing and pushing so I will have a couple of sets soon running in the 9's and pushing for more

I have seen that a lot of China castings that are better than
American.. as much as I hate to say that... my MP M1 manifold
looks like crap based on casting quality

Lol... Nah.... Just back in from being out on the lake. 95 degrees today, and the water is 86. Little too much sun I think.
Nobody says they may not be good, at any power level, just long term dependability seems to be the concern. I think it's a valid concern at this point in time. Don't you?

No I don't. I honestly think at this time a ProMaxx head is BETTER than an Edelbrock head. I've never owned a Proform head (now Speedmaster) and never will. Way to may stories about falling out seats, broke valves, and broke springs for me to invest in them. I love the looks of these heads so far and can't wait to see how they perform out of the box with the flow numbers I provided. I hate what has happened to Edelbrock over the years and can only hope the new Victor head shows more Quality. I want a set soon. I usually buy my heads bare and upgrade to a bigger valve but before these are gone I want to try to track down what kind of valves are in them. I should have asked yesterday when I called but forgot.

ive been watching this post.how do the valves look that come with the heads?and i wonder what would have to be done with these to work with a solid roller cam in the .640 lift range.im looking to replace the x-heads on my 340 stroker sometime and these look like the way to go,thanks

Please don't let the china issue get in the way of your technical assessment of what the heads are capable of.

The knowledge/experiences you share are greatly appreciated.

Edit

The fellow making these videos is a thief and full of crap FYI.

Want to tell us why he is what you say??

Further, WHAT does that have to do with him showing us a head casting? Did he steal it or something?...LOL.

The head he is showing us, is what IT is; has nothing to do with him.

http://classracer.com/classforum/showthread.php?t=62827

Once a thief always a thief thats why...
I have no use for a thief lot a guys are out cash because of that clown.

True, but the vid where he sets himself on fire is pretty hilarious.

Just asking, but would these heads support 530ish horse on a 408 without winding it to the sky?

Heck Ya with some porting work. I've gone 9.73 with Edelbrock heads with a 2.08 valve and stock pushrod location shifting around 6800 rpm in my duster. And these have more porting avalible if I am hearing right that the intake floor is poured solid. I won't be sonic checkng a set till I buy my own

Easy.
I went 10.70's shifting at 6600 with stage 2 eddies from Hensley(275@600) with a flat tappet and 727 at 3400 pounds with a cast crank 416. I figured that was probably 530-550.
Absolutely nothing fancy. Small TTI step headers, excellerator intake, 4150 carb.

Sounds interesting. I'm wanting to end up running 10:50's @2850#. Should be a piece of cake.

As long as you don`t go EFI that should be easy.........

EFI is easy!

That`s what Mr.Pbody said...........AT FIRST.............

What you naysayers are not getting, and probably that's because you don't want to, the China supply line is very much like a Chinese restaurant. The list of options is endless.

So when the Promaxx head guy orders up a set of bare castings, he can order any alloy he wants. It might cost him $5.00 per head.

He may be able to make mods to the casting cores as well. Bryce Mulvey talked about that when he was blowing up Moparts about the Airwolf heads. It was pretty clear from what he said that they were cast by/for ProComp and he made some changes to the port shape.

When you talk about keeping work in the USA, fine. I can go along with that. I write that into every specification I produce. BUT, keep in mind that the casting is probably the cheapest part of the head. Handling, machine work, valve guide and seat supply and installation, springs, valves are added. Then there is advertising and making the boxes and shipping from the port to the machine facility.......get the picture?

I bet if Keith Black used a Chinese foundry he'd be able to triple his output. Whoever said it above has it right, it's hard to get any product, much less a quality product, from an American foundry. They're dirty, the work is hard, and there are many dangers. Thus, the number of foundries is dwindling and the good ones are overbooked. At the same time that it's hot, dirty work, the foundryman has to have experience because casting is more of an art than a science. So foundries can't just hire someone off the street. And, the good ones probably can't expand because of the Not In My Backyard factor.

Kudos to pittsburghracer for keeping an open mind.

R.

Thanks and that was well written but I will go one step further. PA isn't the greenist state in he nation but the EPA really hit us hard in the specialty steel market. As a Millwright we used to make and pour our own babbit bearings for our equipment. I retired in 2010 but they stopped us from work like that yeas ago and you should have seen the junk we were forced to use. A local bronze shop was totally closed down

At first I didnt know it.. and my cam didnt help
with as much overlap it had... now that I understand
it.. its nice stuff.. I'd rather sit in the car and
push a few buttons... some day even you will come around
and to say it doesnt work well because of one person..
thats pretty lame

I've been helping a buddy of mine with an EFI swap on a Slant. It can be pretty intimidating, but pushing buttons is a lot more fun that changing jets and such, and smelling like gas.

Slant....... Your not eating enough beans... Lol

Was just pointing out that it can be harder than just "pushing buttons" but I WILL NEVER go EFI since I've learned from some of the the best at Carb tuning w/overall good results.........LAME?

For me it could have been as easy as pushing buttons
but I didnt know that... with a little help I understand
it now.. much better

Hey, no different than any of us who've struggled over the years to figure stuff out.......... I still struggle..........

But my struggle is on a computer... I dont even
have to get out a wrench.... plug in

40 plus years of changing carb jets for me and I will continue doing so. Way to many carbs sitting here and very happy with their preformance.

By the way what the heck does this have to do with ProMaxx heads. Wholly post robber Batman. Lol

At least it hasn't degenerated into the usual quagmire of name calling.

Sorry.. no more comments out of me

That's a Small Block Chevy Head he's cutting up. NOT a Mopar head.

Oh I know and will be sonic checkng mine befor I start porting. These heads are my friends and are going on a steer car that may hit the track once in awhile. I really try to stay off the bottom as much as possible but it's nice to know meat is there if needed. Edelbrocks are a little lean in that area

Hey can we get an update on these heads?

I edited some of my detracting posts, Im a real dick some days.

But since you have hands on these heads...... whats the report card look like?

Like I said above this was a freebe job for a friend. It is still mounted to my flowbench as I ended up in the hospital with a few health issues and I'm very limited in what I can do until hopefully getting straightened up. If my health returns I will have a set of my own and will dig deeper into them. Th four valves that I removed so far feel great as far as valv guide clearance. I told my friend that if he wants to come over some evening and tear them completely apart I will assist him so he can as a 22 year old learn the process. I truly like what I see so far and will update when I have more info. This head will go 300 plus CFM with little work

Hope you heal up soon.

Thank you very much

Mr. Pittsburghracer:

I really appreciate your contributions to our hobby. Get well soon and get back to the wrenching!!!

John, I hope you heal quickly. I to enjoy your tech posts and contributions to this forum. I will be praying for your speedy recovery. Jim

I just hope you get better to get better, screw the web and car stuff, getting older and dealing with health issues suck!

Thanks guys and fingers crossed all goes well soon. Its crazy how good you can feel at 59 years old and how quickly a bad spell can set you back at 60. Last year i started walking and called it my RiverWalk program. I cut unhealthy carbs and worked up to walking 4 miles a day 5-6 times a week. I lost 55 pounds and although I didn't hit my target I FELT GREAT. Then Winter set in and stupidly I stopped instead of going to the gym. On on the downhill slide we went with 4-5 health issues so far this year. I started walking again this week for the first time since April so now its up to me and the Doctors.

During the time this post started going south 7-23-16 to 7-24-16 I was sicker than a dog and ended up in the emergency room. I apologise if I offended anyone but posting from my cell phone only I was trying to keep this post on point for myself as much as others so hopefully some good info could be shared. Trust me I tried to research them before my Friend bought them but there is almost NOTHING floating around. I'm super glad he bought a set of heads that put Edelbrocks to shame and I for one will never buy another set of Edelbrock RPM's till the issues are addressed. Victors???? yes I hope to have a set SOON.

wish you all the best healing up

Dateline, Pittsburg 8/24/16: Any updates????? Hope you are well, sir.

Do they have a magnum version??

No updates, I'm finally back in the shop some and he was sick. Its up to him now to take them apart with my tools if he wants to and check the remaining valve guides. The 4 I took apart to flow the head were great. As I said earlier everything I did on these was free and he won't be charged. We both wanted to see what the flow numbers were so I threw the FREE part out there. Now its up to him to take the rest apart to check the rest if he chooses to do so. I'll help but I have to much of my own work to do. I'm still slowly getting my stamina back but by time the yard work is done and my 3 mile walk I'm to tired to hit the shop for very long. Thinking I will buy my set bare, have them opened up for a 2.08 valve, push the pushrod over, port them, and see if I can improve much on the hair over 315 cfm I've gotten out of a stock location pushrod on my Edelbrock heads. If I can't find 325 PLUS its not worth the added costs.

Not sure but check Jegs website or ProMaxx.

Ok

Curious if you have any flow data?

Or does anyone else?

I hear crickets.

Chirp, chirp, chirp...

did you see the first post in the thread???

Lol...thus the crickets! No I came in late and never clicked back far enough.

Okay, done being stupid now.

He picked them up over a week ago and finished striping them down. He said all the other valve guides felt great. Not thinking that the engine will be together this year as he has SEVERAL projects going like most of us do.

Any updates??