HOWARDS SBC CHEVY HYD. OE ROLLER CAM 600/581 LIFT 233/241 DUR @.050" # 186755-10
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FOR SBC CHEVY 383 406 421 427 434 ENGINES.
HOWARDS HYDRAULIC OE ROLLER, (STEP NOSE) CAMSHAFT .600/.581 LIFT .251/.255 DURATION @.050" LOBE SEP: 110º
This cam has a regular size base circle. See our other listings for this cam in a reduced base circle size for use in engines using a 4.00 stroke crank.
PART # 186755-10 For use in oe roller blocks.
Part # 116755-10 Retro style. For use in early style blocks.
Part # "S" at the end of the part number is for the small base version of a cam very similar to this profile.
Valve lift with 1.5 Rockers: Intake .600/Exhaust .581
Duration @.050": Intake .251/Exhaust .255
All Howards™ Cams use the highest-grade race quality cores available. Howards™ Cams are manufactured on dedicated high precision CNC cam grinding machines.
The cam gear is compatible with any standard steel or cast iron distributor gear. No bronze distributor needed. This cam is considered an OEM style, meaning it must be used in a roller block; it cannot be used with a non roller block. Retro style cams are available in our other listings. This auction is for the OEM style roller cam. Many camshaft accessories available in our other listings.
This cam is to be used on sbc engines that are equipped for factory roller cams. These blocks came out in the late 80's in the Corvette and early 90's in the Chevy trucks. As you know, all of the sbc roller engines in this era were throttle body or tune port injection. This cam may not be compatible with those setups, but many are using the oe roller blocks and running a carbureted setup and this cam is well suited on those type setups.
We have used this profile on many different buildups with amazing results. The dyno results are listed below, and show many different engine sizes and combinations.
If you would like expert cam recommendations for your engine, contact us (through the "seller information" tab or through our tech line, 423-722-5152) with the information listed below. We will tell you what cam is best suited for you. Running a cam that is too big in a given combination is not only pointless for making increased power, but creates a increased loss of drivability and unnecessary wear on the valve train. You must have sufficient cubic inch and/or compression ratio, coupled with correct size cylinder heads that will allow enough flow, to justify a particular size cam. Bottom-end and mid-range performance are always affected when you increase cam size, but it would be affected even more if a cam selection is over-sized to the point that no top-end power is gained. So choosing too large of a cam becomes a two-fold problem. Tuning also becomes more difficult with larger than needed cams.
For a recommendation on the best cam for you, please contact us with us the following information:
All Howards cams use the highest-grade race quality billets available. The hydraulic and mechanical flat tappet camshafts are 100% Rockwell checked and Parkerized to ensure the highest quality control standards available anywhere. Howard's Cams is proud of its equipment, manufacturing all of its cams on dedicated high precision cam grinding machines.
Howards maintains these exacting standards right through the shipping process. All Howards camshafts are packaged and shipped in a unique, hard, high impact, reusable plastic case. This ensures that that you, our customer receives your new Howard's Cam in the same exacting condition it left our factory.
We have posted actual dyno results below of several different size engines with various combinations of intakes and cylinder heads using this cam. The dyno report will tell what size and brand of cylinder heads used, single or dual plane intake, rocker ratio, carb size, and total timing. These are all pump gas engines for street and strip use. Our experience is vast with these cams. Few if anyone selling cams will have actual results to post. We are also going to list the characteristics of this cam, such as drivability, often referred to as street manners, as well as what stall converter is recommended and final gearing for a particular engine size.
Correct lifters to use with this cam: Howards # 91160 Max Effort tie-bar lifters. Regular low cost drop in street grade hyd. roller lifters will not perform with this cam. Even the regular street series tie-bar lifters will not do well with this cam. If you think you're going to be running in the upper rpm range (6300), then you need to invest in the Max Effort tie-bar lifters for sure. The regular Howards tie-bar street lifters encounter light valve float right at 6000 rpm in our engines. This cam lift and duration, coupled with high rpm, demands a semi race grade lifter to avoid valve float, and the Max Effort lifters are excellent for this. Comp Short Travel lifters are also an excellent choice, but they require greater spring pressure to operate at their best. We prefer the Howards Max Effort lifters. They are also much quieter than many of the race grade lifters on the market. Our experience on the dyno has proven this.
As each cam we offer gets larger in lift and duration, we offer different lifter recommendations if you have noticed. Lifter requirements are based on cam size in lift and duration, and what rpm range they will run up to in a given combination. Also add to this the spring pressure you're running can make a difference on what lifters you will be able to run.
Increased spring pressure on the nose of a cam is a great defense against valve float, but some street lifters do not operate well with this pressure. Our next size up cam from this has different recommendations than this cam. It is very important to heed our warning about using incorrect lifters. It's not just about low grade lifters, it's also about lifters that are not designed for high lift/high rpm applications. We use five different grades of hydraulic lifters in our engine program.
Recommendations on using this cam in a 383 or larger pump gas street rod engine.
This cam, coupled with our single plane intake and our forged pistons with 1.6 rockers, will produce right at 570 horsepower at approx. 6,700 RPM on a 11.2 compression ratio 383 engine using our NKB cyl. heads. You would obtain close to the same hp numbers with our one step down size numbers in a 383 with normal compression ratio numbers. This cam is better suited in a 406 or larger cubic inch build. This cam requires a minimum of 11.5:1 compression ratio in a 383 but could use more to gain its full potential. The compression ratio requirements go down in larger cubic inch builds. This cam is an excellent choice in 421, 427, and 434 engine builds, for pump gas street rod use. We do not even offer this cam in our 383 or 406 engine builds for street use. The optimal compression requirements are higher than what is safe for pump gas use in our opinion, but when used in the 421 or larger cubic inch builds, the compression requirements are much less, and drivability is much better.
This cam is capable of making over 600 hp in the 421 or larger engines on pump gas with compression ranges in the mid tens, providing you have a decent set of heads. Our NKB 200cc heads actually broke into the 600 hp range on one particular engine build with this cam. If you do decide to run this cam in an engine with a 4.00 stroke crank, then you will need the small base circle version. You will see an "S" at the end of the part number for the small base circle cams. See our other listings for these type cams. For those running a 3.875 stroke or less, you can run the normal base circle cam with proper rod clearance.
We recommend a stall converter of around 3000-3500 for any 383 or 406 engine build. Stall requirements are less on larger cubic inch engine builds. Final gearing would need to be at 3.55 or numerically higher. The weight of your car is also a factor as what your final gear should be. This cam does make very good overall power, but would be considered very aggressive in a 383 or 406. The idle sound with this cam is very erratic (lopey) when used in a 383 or 406.
You would not be able to run overdrive, power brakes, or air conditioning with this cam in a 383 or 406. Valve train life and reliability are reduced with this cam as compared to lower lift and duration cams. This cam puts your setup into the Pro-Street league when used in a 383 or 406.
Drivability is radical with this cam in a 383 or 406 engine build.
If your car is over 3600 lbs, we advise against the use of this cam, unless you have a deeper than normal final gear. If your engine build is a 406 or larger, this cam will be somewhat tamer and more suitable in heavy or taller geared vehicles.
Our dyno results are very accurate. As time goes by, you will see more dyno results posted below of engines using this cam with various combinations. We use a group of approximately 5 sbc hyd. roller cams in our engine program. We tested many profiles over the years. This group of cams has outperformed many others with consideration to drivability. There are many cams on the market with similar profiles that do not perform anywhere close to the cams we have chosen.
Below are dyno results on various engine sizes and combinations with this cam. The specifics for each dyno run are found in the upper left-hand corner of the test description graphic. 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 427 engine with this cam and a single plane intake.
This engine has a 4.00 stroke crank, and uses the small base version of this cam. Same or near identical profile. This cam makes very impressive power considering it's a hydraulic roller style cam. We use it in most of our 421, 427 and 434 engines as cam choice 1
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