Thanks Eric , as always you never disappoint with your findings . Ya , I had crappy experience with P-comp as well , way off seat machining , worn out guides on S block , and pulled stud casting right out on a big chev , so , no more of those , lol .
Good video Eric. My guess is the ProMaxx intake valve is not back cut. All the ones I have bought never have been. I always do a back cut on them, a little chamber work and some minor short side work on the intake and exhaust and the valve job they come with. All that I have used went on 496 that end up at 10.25 to 1 and have been great. Hydraulic roller camshaft, 9.8xx at 3500lb and run pump swill. The cars are very well set up, so it doesn't take much to get them down the track. Overall a great head. I'm sure you will make anything better than I can.
Eric, thank you for taking the time for this, very professional! I did not realize what a big difference the valves make. I ported a set of World Products Merlin 3 heads. Really easy, there is lots of room on a BBC vs a SBC. If building a BBC I would only buy a head made in the USA. And most of them have raised exhaust ports, this creates nothing but problems. Brodix makes the best BBC head IMO.
Really interested in a future review and testing of the Promax oval port 290 head. Hopefully it's a budget solution for a heavy street cruiser. Thanks Eric!
What I've been curious about with alot of these Chinese heads, what actually scares me off of using them, is the thought of the valve seats actually falling out. I've heard of it happening with budget heads for other motors, and even with OEM heads, like the modern hemi engines. Is that an issue with these heads?
always good content, can you throw a vid together on the 185cc SBF chinese head? The 302w's are a good budget builders but are weak on the HP front compared to other engine combos.
I've got the pro max cnc version 352 cc intake with afr 2.35 valves they flowed right around 430 on long runner and 420 short runner around 300 on exhaust pretty sporty head on my 564 ci bbc
Hey there Eric, I've slowly grown into machining, mostly head rebuilds. I haven't done performance work, but have been trying to learn. I've only been grinding a 45 on my valves, but I have two machines. Would working a 30 degree back cut be worth the 10 or so mins to do while I'm already refacing them? Or would it just be pointless on stock heads? Just seeing if I couldn't improve quality for a customer when possible
As usual always the best information provided. A quick Google search has each promaxx head costing $1,100 dollars more than the AFR enforcer head. AFR is using quality valves and springs. And the flow difference just can't justify the extra price. So does the AFR have a quality or longevity issue? Where it's going to fail and take out the engine? For a Chinese head Promaxx has an insane price tag.
I don't know why people act like American made is better... i just paid DOUBLE what a chinese intake would cost to get a RPM Performer $440 (small block mopar.. Edelbrock screws us just cause they can) And all the holes to bolt it on are .125 too far forward (gasket actually hangs over into the port)... another guy on the mopar forums has 2 victors with the same issue. American made is no better although you pay a lot more... BTW... edelbrocks response is umm yeah.. that's wrong but we have never seen it before (of course) and we can't replace it cause we don't know when we will have one.. sorry.. sorry bout the rant but a bit pissed off bout it still.
@@njclsx4252 They were cool bout it.. but didn't want to believe me even with pics til i showed them the forum post from a professional porter showing the issue
People are misguided about Chinese manufacturing and have been for a couple decades. They will make whatever is required. The importers, distributors and retailers set a price and demand a product built to that price point. The Chinese companies are happy to oblige. That doesn't mean they are cheap, it means the consumers(in our case Americans) are cheap. Chinese companies can and do build top quality up to mil spec or aero-space quality products. Oddly enough, when that spec is called out the price falls right in line with any other world market manufacturer making similar products. They aren't building and putting up satellites on rockets made with harbor freight tooling.
Eric - what is the max cubic inch you would run the 317's on? I have a 555, flat top piston currently running an old Edelbrock 6055 casting on and have been looking at the Promax 317s.
Thanks Eric. Very good information. I would agree with another comment that suggested the same comparison with the SBC. I just had a SBC built by Jeff Taylor Performance and he used Pro Maxx heads. I was not familiar with Pro Maxx and your video answered some questions.
Eric, do you or anyone else know anything about the Blueprint BBC head part number PS-8012? it's a Chinese casting with a 358cc runner, 2.30 valve and .300" raised D shaped exhaust port. Wondering how they compare to the Chinese heads you just tested. They also offer a 317cc runner and both retail for $1,299 complete set up for hydraulic roller. It seems possible they may offer more potential then the other Chinese heads with the raised D shape exhaust port when fully ported. It looks like the Blueprint and the ProMax may share the same D port exhaust shape. Just wondering if you guys know anymore about the Blueprint heads?
I would have enjoyed seeing the Flotek included. I am expecting the rest of the parts I need today to be able to assemble them with Ferrea valves for a 489 cu in marine engine I am building for a guy.
ProMaxx and FloTek BBC 290, and 315 (317) models are essentially the same. FloTek does carry a cheaper BBC 320 and 360 which are made by a different manufacture, and not as good. FloTek 290 is a great head on 489-511 cubic inch engines, it's all any reasonable person needs on the street, and will crush many rectangle port heads in average power production below 6800 rpm.
Also wanted to point out that Promaxx’s % of flow (exhaust cfm/intake cfm) were better than the others. Intake cfm is great but if you can’t get the exhaust out, then what’s the point?
I would like to know if you ever heard of J and c enterprises cylinder heads they have a small block chevy head that sounds pretty good and reasonably priced
Can you really get the 317 with a 2.25 valve? I have a set on a 496 I built for a customer and I think they are great, but I haven't seen the 2.25 available anywhere just a 2.30. Are you able to sell the promaxx heads?
It is the last time I checked. I do sell it and the afr dual plane was tested in a different video. It is better up top than Edelbrock rpm air gap but not through most of the run.
I know you’re a busy man, but what are your opinions on helicoils in aluminum heads from the intake manifold holes? You trust those better than just tapped aluminum? Yay or nay.
I have a set of promax sbc heads sitting on my bench. Really nice looking, but the guilds have a sloppy egg shaped hone job. The seats are out of round valve job. Heads came assembled, they need new guilds and seats . They will basically need to be rebuilt never ran. Piss poor machine work but no one actually checks. But nice castings.
Equal ports are easier to tune, get the most from each of the 8 cylinders. Race teams in NASCAR and NHRA pro stock look at the engine as (8) 1 cylinder engines and try to tune each one for optimal and equal power production. DRCE heads have the ports raised way up, and are a completely different animal to the conventional BBC heads street folks use. In recent years Pro Stock teams have been also making their ports smaller, due to RPM limits, and fuel injection.
@@donavan2676 I understand what the trend is but why did they not chose the port that points to the center of the cylinder? Eric thinks that port is much better, he keeps saying that.
@@racerd9669 DRCE heads do not have stock valve locations, angles, or chamber design. Most have very small combustion chambers with the valves stood up, so the port design is not comparable either. DRCE heads were originally designed to get better alignment between the valve and the carburetor booster. Basically nothing about conventional BBC heads is comparable to DRCE. The heads GM is putting on their new 632 (RSX) are more like DRCE, but still 4.840 bore spacing, not 4.900 like DRCE.
@@donavan2676 I understand all of that, but the port still points at the cylinder wall, maybe Ford new something about port design that GM did not. GM could have reworked the DRC head so the port pointed at the cylinder CL but they did not. Maybe Eric can tell us more.
Is it depend on what the peak rpm the inlet runner should be .like if you had a 496 and peak power was at 6500 then ypu would what the 320 to 330. .if the peak power was at 7500 then won't you want a 345 to 360 range on ypu intake runner
@@donavan2676 How about for a BBC ?? I have them on my motor now it made just shy of 850 hp ...was just wondering if for a few more $$ another head would have made a big difference !!
@@donavan2676 I wouldn't buy them as anything but a bare casting to build but they are the supplier for skip white lots of circle track guys run them for a season then just have another set built for the next season and leave the old ones at the machinist or sell them for a couple hundred bucks as is we know they are soft chineseum castings
@@79huddy Like Eric said, don't waste your money, buy the better castings and then build them. The FloTek 290, 315, and expensive 360 (they have a cheap 360 too that is junk) are really good castings to build from, IMO the best value BBC castings on the market. AFR CNC heads are great, but many people cannot afford their CNC heads, FloTek gets you similar performance for less $$
I have found that only Ben Alameda answers my questions. Uncle Tony ignores, Richard Holdner drops a smart ass condescending comment and you seem too busy. I build motors and have worked for one of the best...Ed Pink, and consider myself somewhat knowledgeable but am always thirsty to learn. RU-vid has disappointed
@Eric Weingartner No worries brother, I wish you all the best and will continue to watch as I've learned plenty about porting from you and it's appreciated very much. 45 years as a machinist, i can put together a stout motor but a bit of a rookie with the magic involving cylinder head and manifold modifications. Keep doing what ya do. Thanks
Lmao..their the same, no they are not the same, yes in fact their the sme head. They really aren't the same head. Their dfinatly are not the same head.
Chinese materials are junk. The aluminum, the valves, springs, retainer etc. Might look the same. But don't buy that crap. No engine parts. Hoses are junk,clamps,quality is all junk.
