SBC CHEVY 327 350 383 NKB-200cc ALUMINUM HEADS 64cc ANGLE PLUG NKB-272-A
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NKB 200cc/64cc ULTRA HIGH FLOW CYLINDER HEADS, ANGLE PLUG, FOR SBC CHEVY 327 350, 355, 383 ENGINES.
Setup for hydraulic flat tappet cams.
200cc RUNNERS, 64cc COMBUSTION CHAMBERS.
THE BEST FLOWING, BEST QUALITY SBC ALUMINUM HEADS ON THE MARKET FOR THE MONEY.
This sale is for one fully assembled set of heads.
The springs in these heads are set up to operate with hydraulic flat tappet cams up to .535 lift. For those running hyd. roller cams, see our other listings for these heads with the part number NKB-200-274.
The NKB aluminum heads have 64cc combustion chambers with 200cc runners, 2.02/1.60 stainless valves. These heads are not built by Procomp, and have no association with them in any way.
PART NUMBER # NKB-272-A
We certainly know where to draw the line with low end products, and we continue to eliminate parts that we once accepted but that eventually had problems. Sometimes it's not that a particular product has had a problem that leads to its elimination; something better just comes along. The NKB cylinder heads are that â€œsomething better" coming along. Considering the price is only slightly higher than our former line of heads, this has to be the best value in a set of cylinder heads we have ever offered. We now use the NKB heads on all of our 350, 383, and 406 engines. The performance has been outstanding on every combination we have tried them on. In the rare event you have issues with our NKB-200 heads, the problem will be addressed. As of today (2/17/16), we have been selling the NKB heads for around 2.5 years. We have sold approximately 3500 sets, and problems have been near non-existent.
We have complete top end hardware kits available for the NKB-200 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-1003-1205, or for those that favor the MLS multi layer style head gaskets, part number TEK-5219-1205, or any TEK kit that has the 1205 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 NKB heads. The 1205 is the intake gasket part number, and that is mandatory for use with the sbc NKB heads.
These heads are also available in straight plug style, and with steam holes. See our other listings for the part number NKB-200-A-274.
Recommended accessories for these heads.
Please see our other listings.
A breakdown of the part number.
The NKB stands for "New Kid on the Block"; 200 represents the runner size, 272 designates the use of 100 long valves, and single springs with a damper setup for hyd. flat tappet cams. You will also see the heads listed with the number 274. The 274 designates the use of 200 long valves with dual springs with a damper, setup for hyd. roller cams. We also have the valve train setup for solid roller cams, and will have the number 583 rather than 272 or 274. The heads listed with the letter "A" in the part number are angle plug design. We also offer these heads with steam holes for GM 400 blocks. These will have the letters SH (Steam Holes) in the part number. Be absolutely certain of what you need before buying.
See our other listings for these heads with our Competition Series PBM valves.
Our NKB-200 heads have been designed especially for us. After receiving many recommendations from our engine builders, we came up with the best quality, best flowing heads on the market relative to cost. The only way youâ€™re going to get a set of heads that flow as well or better will be to spend at least double the cost or more. We have installed these heads on all of our 383 and most of our 406 engines for the past 2.5 years. Many of these engines were dynoed on our Superflo dyno. The engines had every possible combination of cam, intake and carb. The results have been amazing. These heads are excellent in design and quality. Our choice of hardware and precision assembly also contribute to the performance and reliability of the heads.
These heads can be used with outer perimeter or center bolt valve covers.
Flow chart information.
In the flowchart above, the NKB-200s are superior to the Procomp heads in flow numbers, and also edge out the Dart SHP heads on the intake side. The intake numbers are far more important than the exhaust. The overall average flow numbers on the NKB-200 heads are higher than most any brand of non cnc'd cast aluminum heads on the market. We guarantee the flow numbers to be accurate, as well as the horsepower numbers produced by them.
Most importantly, all three of these heads were tested by the same person, on the same machine, (Superflo bench 1020) using the same testing method, on the same day. These numbers show the true difference between each brand, and that's what counts.
The difference in horsepower and torque generated by these new heads is monumental compared to the Procomp heads. We offer four different cam choices with our 383 and 406 engines, and every combination has shown an increase of up to 50 horsepower and no less than 40 hp when coupled with the various combos. We assumed the new heads would generate a considerable increase in power, but to our surprise, they generated even more power than expected.
We tore down the heads that were on our 383 house engine and checked the guides as this was an area we are most concerned about, and found zero wear. The seats were also in perfect condition. We tested the spring pressure to see how much was lost after a brutal 80 or so dyno passes, and saw approx. 5 lbs of pressure drop on the nose, and even less on the seat, and this is to be expected.
Many of the dyno passes were run to 6500 rpm as the large cam needed 6300-6400 rpm to make peak power, and you must run past this to determine the fall off point. The super sized cam (choice 1) was run on the heads towards the end. Considering the size of this cam, it was very impressive to see zero issues with the heads or hardware. We made a good 25 passes with the big cam trying out different carb sizes, jetting, intake manifolds, timing setting, and adding the Super Sucker plate last.
The two paragraphs above were written a couple years ago. We have now sold several thousand sets of the NKB heads. To this date we have had no problems of any kind with them.
ONE YEAR WARRANTY, UNLIMITED MILEAGE.
Here is a rundown on the hardware used in these heads and the assembly process.
Melling High Performance Dual Springs.
COMP CAMS "POSITIVE STOP" VITON VALVE STEM SEALS. # 529-16
We purchase most of our valve train hardware in bulk for our engine program. Below is a copy of one of our invoices from Comp Cams showing several of our rather large purchases of valve train hardware. We have removed the price and our account number for privacy reasons. This is the best way we can prove to our customers that the valve train products we use and sell are genuine Comp Cams products.
IMPORTANT NOTE, MUST READ!
We have noticed several sellers offering these heads with a one size fits all valve springs for dual use on hydraulic flat tappet and hydraulic roller cams.We are sure this is not the proper way to setup the heads.
If they have this one size fits all setup somewhere in the middle spring pressure values of what is required for a hyd. flat tappet and a hyd roller cam, then it would be too much for the hydr. flat tappet cam, and create a wear issue. Putting too much pressure on flat tappet cams is a sure way to kill the cam. If these middle of the road springs were used on a hyd. roller cam, then the spring pressure would be too low. Valve float and its damaging effects, along with a loss of performance, are sure to occur.
We use the correct spring for your setup and it is never the same on a hyd. flat tappet as it would be on a hyd. roller cam. As mentioned above, the spring requirements between a roller cam and flat tappet cam are dramatically different. Even the odd ball solid flat tappet cam has its own unique setup depending on the lift. The one size fits all hardware claims also to work on these cams. We know of several sellers offering this insane setup to unsuspecting buyers, and itâ€™s not the proper way to set up a set of heads. We would not even consider using a spring setup like this, and believe me, the simplicity of it is appealing.
The results produced by these heads will vary greatly depending on the type of setup you are running. The engine combos we have dynoed are what most people use for cam and intake selection, and the results are listed below. The engines dynoed were many 383's, and several 406 cid engines in the 10:1 to 11.2:1 compression range. All ran on pump gas. Our Stage 2.2 383 engine ad has a selection of four different cams. I have copied this info from that ad. This will give you an idea about the capabilities of these heads with combinations of cam, intake, rockers, and carb. This may also help you select the proper cam for your build.
As mentioned, below is just an excerpt from our Stage 2.2 engine ad. We also built and dynoed a 350 engine recently with the new NKB-200 heads for a customer, and will have the actual dyno results in this ad soon. The cams mentioned below are all hyd. roller cams. If youâ€™re using a lower lift than those listed below, then it would be fair to say the hp will drop, but not by much, providing your lift and duration are somewhat close to any of the cams mentioned below. This will give you an idea of what kind of power to expect with these heads, and it can certainly help you choose a cam and intake.
Please do understand that a cam is not included with the heads. This is just a guide to show what you may expect with a given combination when building a 383 engine using the NKB heads.
Cam choice #1
PART # 186755-10 This is a hyd. roller cam for use with OE roller blocks only.
PART # 116755-10 This is a retro style hyd. roller cam for use with non roller blocks.
Valve lift with 1.5 Rockers: Intake .600/Exhaust .581
Duration @.050": Intake .251/Exhaust .255
This cam choice # 1 is very aggressive in the 383 Super Stroker engine. We have not offered this cam in the past with any of our 383 engines. This is the same cam choice used in our 421/427 engines. The reason we decided to try it in our 383 Stage 2.2 was to see what the max potential was with our new NKB-200 cylinder heads. We pumped up the compression a bit with a flat top set of pistons, topped it off with a set of 1.6 rockers, and went with the Single plane Hurricane Plus intake, added the Super Sucker plate, and produced an amazing 560 horse power at 6500 rpm with 502 lb ft of torque at 5400 rpm.
Actually, the engine produced only 4 hp less at 6400. The horsepower numbers are very accurate. We performed the testing on our new Super Flo 902s dyno. The flowchart above certainly explains why we achieved such numbers. This setup is considered Pro street, and only usable in very lightweight cars with proper gearing, and a stall of 3200-3500. This is due to the cam size, 1.6 rockers, and intake choice. The compression ratio of approx. 10.7 was used, and cannot be run in very heavy vehicles with tall gearing. The drivability would be considered poor with this setup in a medium to heavy weight vehicles, (3400 lbs. or higher)
Those not familiar with Pro street setups should educate themselves on the subject before choosing a cam and intake such as this.
Buyers wanting decent street manners, explosive power off the line without the need for deep gearing, and with the need for a high rpm stall converter, need to stay away from this setup. Below are three more choices that will better suit your needs.
On the flip side, those that want the most powerful pump gas 383 available and enjoy the thrill of a pro street setup need look no further. This setup would please the Pro street minded to a very high degree. This cam beats the ground with no mercy. Give it the right stall, gearing, and a set of ET streets in a lightweight car, and you will have that sound and feel of power with acceleration unlike any 383 has ever achieved on pump gas considering the cost.
For those demanding top end power in the 550 hp + range and not wanting to sacrifice too much drivability, then I recommend building a 406 engine with the same cam setup. The 406 engine will move the torque band down much lower in the rpm range.
Cam choice #2
PART # 180345-10 This is a hyd. roller cam for use with OE roller blocks.
PART # 110345-10 This is a retro hyd. roller cam for use with non roller blocks.
Valve lift with 1.5 Rockers: Intake .565/Exhaust .580
Duration @.050": Intake .245/Exhaust .253
This cam choice (2) coupled with our single plane intake and 1.6 rockers will produce right at 530 horsepower at 6,400 rpm in a pump gas 383 engine with our NKB heads. Compression ratio would be right at 10.5:1. It must be noted that the dual plane intake will have much better drivability, and throttle response is also noticeably improved. The engine would feel stronger with the dual plane intake in the bottom and mid range. The single plane intake would have a greater impact on the hp numbers if the engine were setup in race form, as we have seen up to 20hp difference on larger cubic inch engines, and/or higher compression setups with larger heads and cam.
The single plane intake is not recommended for use in vehicles weighing over 3250 lbs. Our cam timing components were left in the straight up position. Ignition timing was set at 33-34 degrees total, using 93 octane fuel. During very hot weather, total timing should be set at 31-32 degrees. This cam choice should only be used in vehicles weighing around 3,500 or less. A final gear of approx. 373 and a stall of approx. 2,800-3,200 is recommended.
Below are our dyno results on one of our 406 and 383 engines with a set of our NKB heads using this cam and a single plane intake. The horse power numbers will usually improve anywhere from 5-10 more than what the dyno results show after the rings have fully seated.
Official Dyno report on our 406 engine with this cam, flat top pistons, and a single plane intake.
Official Dyno report on our 383 engine with this cam and a single plane intake.
Cam choice # 1 and a single plane intake.
Cam choice #3
PART # 180265-10 This is a hyd. roller cam for use in OE roller blocks.
PART # 110265-10 This is a retro hyd. roller cam for use in non-roller blocks.
Valve lift with 1.5 Rockers: Intake .530/Exhaust .545
Duration @.050": Intake .233/Exhaust .241
This cam choice (3) is the perfect all around setup for those wanting a decent bottom and mid range, while still generating excellent power at the top in a 383 engine. This engine will use the same pistons as the cam choice above, but you could have a bit less compression ratio and that would be fine. This cam will make its peak power at approx. 5700 rpm. If your car is in the medium weight range or up to approx. 3,700 lbs, and youâ€™re wanting slightly better streetability, then this is a good cam choice. You still want to keep the final gear ratio at .323 or higher, but keeping the gear ratio on the tall side is more acceptable with this cam compared to the other choices mentioned above. You may choose 1.5 or 1.6 rockers with this cam, but we recommend the 1.5 rockers for better low end response.
This cam should be paired up with the dual plane Crosswind intake for excellent daily drivability. The single plane Hurricane can be used, but the dual plane will have much better bottom end and mid range response. You can also expect a longer valve train life with this cam compared to the larger cam choices # 1 or 2.
Below are our dyno results on one of our 383 engines with a set of our NKB heads using this cam and a single plane intake. The horse power numbers will usually improve anywhere from 5-10 more than what the dyno results show after the rings have fully seated.
Official Dyno report on our 406 and 383 engines with the cam mentioned above. The 406 engine had a dual plane intake, yet still achieved over 500 hp with the NKB heads.
Cam choice #2 and a dual plane intake.
This cam and a single plane intake.
Cam choice #4
PART # 180245-10 This is a roller cam for use in OE roller blocks.
PART # 110245-10 This is a retro style roller cam for use in non-roller blocks.
Valve lift with 1.5 Rockers: Intake .500/Exhaust .510
Duration @.050": Intake .225/Exhaust .231
This cam choice (4) has a slightly lower lift and duration than the others offered above, and is highly recommended for use in heavy vehicles like full size sport trucks or very heavy cars. The low end response with this cam is very good. Compression ratio in a 383 could be as low as approx. 9.5:1 with this cam. Slightly higher would be recommended in a 350 build.
The rule of thumb with cam size is that the smaller the cam in a given application, the more improvement in low end response. One more benefit to the smaller cam is that the requirements for lower gearing and higher rpm stall converters is reduced. A final gear ratio of 310 would be acceptable with this cam. The bottom end power would be much better with this cam than with the other choices above. This would be the only choice for those wanting to run an overdrive transmission such as the 700R4 and cruising at around 2000 rpm in overdrive. A stall converter of 2,200 would be the minimum for this cam.
Valve train life is extended greatly with this cam as compared to the other choices listed above, drivability is at its best. Low and mid throttle response is very strong. This cam choice will also produce the greatest amount of vacuum at idle compared to those listed above.
Official Dyno report on our 383 engine with our NKB heads and a single plane intake.
This cam and a single plane intake.
THE CAMS LISTED WILL COVER MOST NEEDS FOR ANY STREET ROD.
An excerpt from our engine ad about our new dyno.
Head bolt washer recommendation.
Guide plate recommendation.
Stud Girdle recommendation.
NKB-200 64CC 200CC RUNNER SIZE ANGLE PLUG FOR SBC CHEVY ENGINES
Intake Valve Dia: 2.02â€
Intake Port volume: 200cc
Intake Port Dim: 2.2â€ x 1.2â€
Int Port Location: Stock
Intake Gasket: Felpro# 1205 fits perfectly with most intakes. Should your intake drop too low, then the 1266 gasket will correct this problem. Our line of intakes have worked very well with the Felpro 1205 intake gaskets.
Head Gasket: Felpro# 1003 or our line of GR-30 and GR-40 heads gaskets. Must use head gaskets that are suitable for use with aluminum heads.
Exh Valve Dia.: 1.600â€
Exh Port volume: 70cc
Exhaust Port Dim: 1.356â€ x 1.420â€ w
Exh Port Location: Stock location & bolt pattern
Exhaust Gasket: Depends on what type exhaust you're using. Best to try and match up the gasket to your header or manifold
Flow, Intake: See chart above.
Flow, Exhaust: See chart above.
Head Bolts: We strongly recommend ARP # 134-3601 head bolts. Must use extended reach with head bolt washers or head studs.
Head Studs: PC-2451-Studs (12pt) or ARP brand.
Manifold: Most any. Our line of intakes fit very well on the NKB heads.
Milling: Min. Down to 58.5cc or 64.5 = .060â€ See info in this listing for details on this.
Pistons: Most 23Â°aftermarket pistons.
Push Rod length: When running a hyd. flat tappet cam use 7.900 length. See our other listings for these.
Push rod Guide Plate: We strongly recommend Dart flat guide plates. See our other listings for many accessories.
Retainers/Locks: Chromoly Steel Retainers, with 10Â° Comp brand machined locks are used on all of our heads.
Spark Plug: Straight, .750â€ reach, gasket, Autolite 3923 or NGK 4554 for one step lower heat range than the Autolite.
Spring Pockets: 1.550â€ OD (.030â€ deeper max)
Springs: 1.46 large size outer diameter with internal damper.
Valve Length: 5.015â€ (+.100â€) for hydraulic flat tappet cams.
Valve Stem Dia: .3415â€ - 11/32â€
Valve Train: STD SBC 3/8â€ or 7/16â€ stud mount
Valve Guides: 1/2â€ OD Int = Mag-bronze Exh = Phos-bronze (.002â€ press)
Valve Guide length: 1.950â€
Valve Guide clearance: .0014â€ - .002â€ (with our .3415 dia. valve stem)
Valve Guide Spacing: 1.890â€ moved .030â€ from stock
Valve Seats: Hardened Ductile Iron, .006â€ press
Valve Seat dim. Standard
Valve Seat angles: Int = 32Â° - 45Â° - 60Â° - 70Â° Exh = 37Â° - 45Â° - radius
Stud Girdle: Use any standard girdle. Our Gold Series Stud Girdles work very well on these heads.
Torque: Head Bolts = 65 ft/lb
Rocker Studs = 55 ft/lb
Manifold = 30 ft/lb
Block Use: Any SBC Iron or Aluminum
Weight: 59-61 lbs fully assembled pair.
A final note...
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