PROMAXX 200cc SBC CHEVY ALUMINUM HEADS 64CC COMBUSTION CHAMBERS BARE SET
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PROMAXX 200 BARE HEADS FOR SBC CHEVY ENGINES.
64cc COMBUSTION CHAMBERS, 200cc RUNNERS, STRAIGHT PLUG.
The heads offered in this auction are bare as pictured below. See our other lisings for fully built ProMaxx heads setup to accommodate hyd. flat tappet and hyd. roller cams as well as solid roller cams.
Incredible flow numbers, outstanding quality.
The build quality exceeds that of all low cost aluminum heads on the market.
These heads are highly recommended for use on SBC 350, 383, and 400/406 engines. They are the perfect runner size for mild to Pro-street buildups. Those building 350 engines to Pro-street levels can also make use of the ProMaxx 200 heads.
Used on a 350 engine build, these heads will produce up to approx. 360-450 hp. on pump gas depending on cam size and type, intake, rocker ratio, compression ratio, and carb. When combined with a 383 stroker engine, the horsepower and torque numbers will increase in the lower rpm band dramatically. We have achieved 570 hp in our Stage 2.2 383 Super Stroker engine with a hyd. roller cam and a single plane intake with 1.6 rockers, setup for street use, and running premium pump gas.
We have complete top end hardware kits available for the ProMaxx heads in our other listings. The kit has the correct head and intake gaskets, head bolts with special washers, and stainless intake bolts. The part number is TEK-1003-1206, or for those that favor the MLS multi layer style head gaskets, part number TEK-5219-1206, or any TEK kit that has the 1206 part number in it. The first number is the type of head gaskets, and we offer around 5 different head gaskets that will work with the ProMaxx heads. The 1206 is the intake gasket part number, and that is mandatory for use with the sbc ProMaxx heads
These heads have had extensive bowl blending.
Flow comparision chart.
Note from Skip White, President.
We certainly know where to draw the line with low end products, and we continue to eliminate parts that we once accepted that eventually had problems. Sometimes it's not that a particular product has or will have a problem, but something better comes along. When the NKB heads came to us, we thought that was about as good as it gets in the world of low cost aluminum cylinder heads. Then, ProMaxx came along. The price is a bit higher than our NKB heads, but for those wanting to move up to the next level of quality, reliability and performance, we think they are the best choice.
We have tested these heads extensively before introducing them into our product line. Since the price is considerably less than any of the high end name brand heads, we feel these to be a great value. We offer the ProMaxx heads as an upgrade on our 350, 383 and 406 engines. The performance has been outstanding on every combination we have tried. In the rare event you have issues with the ProMaxx-200 heads, the problem will be addressed. The warranty for these heads is two years, vs. one year for the NKB heads.
We have sold many sets of the ProMaxx 200 heads as upgrades to the NKB heads that came standard on our 350, 383, and 406 engines. This gave us a chance to see how they perform on different combinations compared to the NKB heads. When using any of our four popular cams, the ProMaxx heads outperformed the NKB heads. The most important aspect of the ProMaxx heads is their outstanding quality and workmanship, leading to reliability and endurance beyond any of the lower-cost heads we have sold in the past, including the NKB heads. That’s why ProMaxx is our choice for the best set of heads for the money.
If you receive the heads and don't think what we’re saying is 100% true, we will give you a full refund. If you were to take these heads to a machine shop to have them installed on an engine or just to have them looked over, you would be surprised to find what the engine builders have to say about these heads. They can check them inside and out, and rest assured that the heads will get their seal of approval. When we received our first set, the first thing we noticed was the overall appearance, and we found them to be the best looking heads we had seen in some time. They went on an engine the very next day, and we did extensive dyno testing. Intake installation was very good. Everything lined up very well.
TWO YEAR WARRANTY, UNLIMITED MILEAGE.
In-house dyno testing.
As of 9/15/2013, we completed installation of our brand new Super Flow 902S dyno. In the past, we outsourced our dyno work. In order to do the research and development we truly wanted, we made the $105,000 investment. Every aspect of our engines can now be monitored, calibrated, and tuned. More importantly, we can see what combos generate the best power, taking drivability into consideration.
We have built an engine that we refer to as our "house engine." Every week, we put this engine on our dyno to research different combos of head, cam, intake, carb, and setting changes to optimize the engine. The ProMaxx-200 heads have been tested many times on our house engine without fault. Similar testing was done with our NKB heads. We have torn the engine down once already and checked the ProMaxx heads thoroughly. We checked the valve guides for even the slightest wear, and all of the hardware. The ProMaxx heads were in perfect condition.
Head bolt washer recommendation.
The ProMaxx-200 heads require the use of special head bolt washers, and extended reach head bolts. Using stock length head bolts will not allow the use of the special washers required, as the OE bolts have a limited amount of thread on them. Not using the special head bolts and washers may cause serious damage to the cylinder heads. See our other listings for many of the items needed to complete your engine build. The correct part number for the head bolts to be used with these heads is ARP-134-3601. We offer the ARP head bolts with the top end kits.
Guide plate recommendation.
We strongly recommend the use of the Dart guide plates with these heads, or with any aluminum heads for that matter. These guide plates will allow better rocker tip alignment due the fact the rocker stud holes in them are oval shaped. We use them on every set of heads we install on our engines, including the Dart Platinum Pro-1's. The rocker tip may end up offset to one side more than is acceptable, and the Dart guide plates allow a decent amount of correction. The variances in stud position to valve guide alignment vary on all brands of heads. The rockers could also contribute to this issue, as the trunnion or rocker body could have variance. By having proper rocker tip alignment, you are distributing the pressure on the valve tip evenly. This not only reduces uneven valve tip wear, but also prevents undue stress on the valve guides in the heads. See our other listings for many of the valve train products that you may need for your project. The part number for the correct studs and guide plates to be used with these heads is 38-GP for those running 3/8's size roller rockers, and for those with 7/16's roller rockers the part number is 716-GP These kits are available in our other listings.
Do not use stock OE pushrods with these heads. The spring pressures on aftermarket heads is somewhat higher than on OE heads. Combine this with the larger lift and duration cams often used, and stock pushrods may flex or permanently bend. The stock pushrods are usually made from a mild 1810 steel that has been heat treated. Under high rpm they will usually flex and cause a loss of lift resulting in a power loss. The engine will usually run erratically when pushrods are flexing. The Spintron valve train dyno proves that inadequate pushrods will flex to a great degree as engine rpm increases.
Some GM pushrods have a welded ball on them, and they stand a greater chance of breaking off with the use of larger than stock cams, and increased spring pressure. We offer pushrods made from 4310 chromoly with an .080 wall thickness. They are superior to any stock pushrod. Our prices on them are the best you will find.
Pushrod length may vary due to other factors such as block deck height, gasket thickness, and, as mentioned, brand of rockers. You certainly want to be sure you have the correct pushrod length. If you end up 50 thousandths plus or minus from the perfect length, it's usually acceptable but any more than this, and you will affect valve lift. There are many low cost pushrods on the market in the $29-$39 range. These are totally unsuitable for use with these heads for the many reasons mentioned above, and they are not guide plate compatible. They usually have a wall thickness of only .065. These types of pushrods will cause problems when used on a high performance setup. Many factors determine pushrod length requirements. The 7.250 length is the most applicable for hyd. roller cams, and 7.900 for hyd. flat tappet cams. Should you purchase a set of pushrods from us and find that the length is not suitable, you may return them, and we will send out the size you request.
Stud Girdle recommendation.
If you are running full roller rockers, we recommend tall valve covers, and this can cause the oil that is pumped up into the top of the heads to not be deflected back down onto the valve springs, valve tips and roller rockers. The lack of oil on these parts can lead to not only a lack of lubrication but also to a lack of cooling on these parts. Heat transfers up the valve stem from the combustion chamber. This heat is very high in temp, and may cause serious damage to the valve guides, springs and roller rockers.
The cure for this would be to install a low cost set of stud girdles. Stud girdles increase stability to the rockers’ studs, eliminating flex that is may be present to some degree when running cams several sizes over stock, not to mention increased spring pressures over stock. Stud flex robs your engine of power and smooth operation in the upper rpm ranges. As mentioned above, another very important aspect of using stud girdles is that they deflect oil directly back onto the valve springs, valve tips and roller rockers. On a stock engine this is not an issue due to the fact that stock valve covers are very close to the top of the rocker arms.
If you have ever removed the valve covers on an engine while it is running, you would notice that the oil sprays up out of the back side of the rockers and goes in all directions. The most important reason that oil is brought up into the top of the engine is for lubrication and just as importantly, to cool the valve train components. The oil temp does have a great cooling effect, as its temp is only around 215 deg. and the heat that is transferring up into the valves and springs is far greater than this. If oil were not flushed onto these parts, lack of lubrication would be just one problem. Valve guides and stems that are heated up to high temps, and also lack the proper lubrication may experience excessive wear. We suspect that these parts may be stressed due to the oil not being redirected back onto them, and stud girdles would positively protect these parts to a great degree.
We now use them on every engine we build regardless of the degree of cam and spring pressure. Those running cams that are above 460 lift should use stud girdles, since this is about the level that stud flex may come in, especially when running the smaller 3/8's rocker studs. Excessive valve guide wear along with other valve train components can be very expensive to repair.
IMPORTANT NOTE CONCERNING ROCKER ARM STUDS.
If you have been a regular shopper with us, you will have noticed we do offer some knock-off products that are made off-shore. We do also sell many products made in the USA. We have always been very particular as to the quality and workmanship of such products, while considering the cost. We scrutinize our products very carefully and refuse to sell products that simply don't meet our standards. We have now eliminated another of the low cost knock-off products from our line. The low cost imported rocker arm studs have shown numerous problems unlike those in the past. We have looked at several others on the market, and still find many issues with them that are not acceptable.
Many of the studs had run-out in the shaft of up to an eighth of an inch. This caused major problems with rocker alignment, and depending where the position was when the stud tightened up, would determine the direction of the rocker misalignment. If the warped stud was facing toward or opposite the valve, then the roller tip would would not be centered to the valve tip. This would then create a loss of lift and cause increased wear on the valve tip.
If the warped stud tightened up in a side to side position, then this would allow the rocker tip to be cocked on the valve tip. This would then side load the valve tip with undue pressure, creating a serious wear problem on the side of the valve tip and create excessive wear on the valve guides in the heads. This also side loaded the rocker trunnion and front roller, creating an excessive wear issue in the roller rockers.
We also found a difference in the tread pitch and depth compared to the ARP studs. The rocker studs in an engine are under a tremendous upwards pull and improper thread design may cause the studs to pull out of the head. The ARP studs screw into the heads with a very precise fit and feel.
After thoroughly comparing the ARP studs and several off shore models, it is certain that we will never offer the off shore studs again, regardless of the price difference. They were never as bad in the past as what we’re seeing now. This run-out was most likely caused by improper heat treating methods.
We are aware of only one other rocker arm stud besides ARP on the market of decent quality, and that's from the GM Performance division, and it's fair to say they are most likely supplied to GM by ARP under private label.
We have rejected many products that are outright junk and would cause serious issues in your engine only to see other sellers offering those same exact products.
Studs and guide plates are NOT included. Other sellers may include these items but rest assured, they are usually not suitable for these heads. We use nothing but the Dart adjustable guide plates and ARP rocker studs when we build an engine using these heads, as they allow for perfect alignment of your rockers. See our other listings for a full selection of accessories.
See our other listings for valve train related items that you may need for your project. The part number for the correct studs and our Dart guide plates to be used with these heads is 38-GP for those running 3/8's size roller rockers, and for those with 7/16's roller rockers the part number is 716-GP These kits are available in our other listings.
Torque specs for rocker arm studs is 50-55 ft/lbs and you must use thread sealant on every stud.
We are glad to offer many great low cost items, as well as the high end products, but will always give careful consideration to quality, functionality, and overall value.
Most sellers do no testing whatsoever on the cylinder heads they sell. We do more than
just flow testing before we market a new style cylinder head.
The video clips say it all. A must watch!
Please watch the video clips below. Jason from ProMaxx sent these heads to Tony at Headbytes for testing. It's obvious from the videos that Tony enjoys doing reviews on cylinder heads, and it certainly complements his head porting business. Tony offers professional head porting services, and has seen many heads through the years that were not worthy of extensive port work. His skills and porting work on cylinder heads are well known in the world of racing. When we saw the video clips, we were very impressed. All six of our engine builders watched every clip, and were more than convinced that these heads were of outstanding quality and workmanship.
We did a thorough inspection of the heads ourselves, including flow testing, measuring the valve guides, measuring concentricity of the seats to the valve stem, lap marking our valves to see that they mated up with the valve seats correctly, and making numerous observations of the heads in general. We spent many hours critiquing these heads, then did extensive dyno testing. The testing that Tony did went beyond our scope of knowledge, and these video clips were what convinced us to take on the ProMaxx product line. The testing on our end, coupled with the testing done by Tony, told us that we now have the best cylinder heads on the market considering the low cost. You would have to spend some serious money on a set of heads to exceed these in performance and quality. As you watch the video clips, you will see why many of the low cost heads on the market have had problems, and still do have problems. Even some of the name brand heads on the market have had issues mentioned in these videos.
Jason from ProMaxx tells us that defects or dissatisfied customers are non-existent with these heads, and they have been on the market for a good while. There are plenty of problematic low cost heads on the market, not to mention heads that flow poorly. We have been down that road in the past, and we take no chances when it comes to cylinder heads. Please watch the video clips below and share your thoughts on these heads. Our company founder, Skip White, will personally respond to you if you have any questions. Please send us an email through the contact tab. More valuable info on these heads is listed below the video clips.
Our Stage 3.0 406 dyno results with the ProMaxx-200 heads: coming soon.
The video clip below was made some time ago. The engine was our 406 engine with the Procomp heads. The ProMaxx-200 heads would have given the engine an approx. 50-60 hp gain.
If you have any technical questions about these heads or if you need to confirm that they are right for your application, feel free to email us with your question, or give us a call at 423-722-5152 8am-8pm Mon-Fri or 10am-3pm on Sat.
For customer support call 423-722-5152.
For overseas shipping quotes, email us using the contact seller tab or feel free to call us.
PROMAXX-200 64CC 200CC RUNNER SIZE STRAIGHT PLUG FOR SBC CHEVY.
Intake Valve Dia: 2.02"
Intake Port volume: 200cc
Intake Port Dim: 2.300" x 1.250"
Int Port Location: Stock
Intake Gasket: Felpro# 1206 fits perfectly with most intakes. If your intake drops to low, use 1266
Exh Valve Dia.: 1.600"
Exh Port volume: 70cc
Exhaust Port Dim: 1.356" x 1.420" w
Exh Port Location: Stock location & bolt pattern
Exhaust Gasket: Depends on what type exhaust your using.
Flow, Intake: See chart above.
Flow, Exhaust: See chart above.
Head Bolts: Must use extended reach with head bolt washers or head studs. We recommend ARP
Head Studs: PC-2451-STUDS (12pt)
Manifold: Most any.
Milling: Min. Down to 58.5cc or 64.5 = .060" See info in this listing for details on this.
Pistons: Most 23°aftermarket pistons.
Push Rod length: 7.900" if setup as a hyd. flat tappet. For hyd. roller cam use 7.250 length.
Push rod Guide Plate: We strongly recommend Dart flat guide plates. See our other listings these.
Retainers: Steel 10° Comp brand machined locks are used on all of our heads.
Spark Plug: Straight, .750" reach, gasket, Autolite 3923 or NGK 4544 Premium cooler plugs.
Spring Pockets: 1.550" OD (.030" deeper max)
Springs: Not included. See our other listings for the best prices on hardware for these heads.
Valve Length: Valves not included.
Valve Stem Dia: .3415" - 11/32"
Valve Train: STD SBC 3/8" or 7/16" stud mount
Valve Guides: 1/2" OD Int = Mag-bronze Exh = Phos-bronze (.002" press)
Valve Guide length: 1.950"
Valve Guide clearance: .0014" - .002" (with our .3415 dia. valve stem)
Valve Guide Spacing: 1.890" moved .030" from stock
Valve Seats: Hardened Ductile Iron, .006" press
Valve Seat dim. Standard
Valve Seat angles: Int = 32° - 45° - 60° - 70° Exh = 37° - 45° - radius
Stud Girdle: Use any standard girdle
Torque: Head Bolts = 65 ft/lb
Rocker Studs = 50-55 ft/lb
Manifold = 35 ft/lb
Block Use: Any SBC Iron or Aluminum
Weight: 60-62 lbs fully assembled pair.
A final note...
Our eBay user id is: skipwhite, and our eBay store name is whiteperformance1. You may have noticed other sellers using a similar name offering similar products. These other sellers have capitalized on our name, and many customers searching for us will inadvertently find them, thinking we are one in the same company. There is only one "Skip White." We are the original premier eBay seller under this name since approximately 2002. We have no other eBay names, nor are we associated with any other company regardless of the similarity in the name or location. Our official company name is Skip White Performance.
If you have any questions about these heads or if you need to confirm that they are right for your application, feel free to email us, or give us a call at 423-722-5152
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