Hi, I currently have a ungoverned predator 212 non hemi with a high flow exhaust, mikuni 22mm carb with a bigger jet than stock (I forget how big I can look in the morning), billet flywheel, rod and piston, with a stock head. I am looking into buying a cam and was wondering which one would be best, I have a spare non hemi head that I ported and is ready for use but don't know how effective it would be without a cam. Any advice on future mods and cam would be great thanks.
Cam upgrade
- Thread starter aidancc_
- Start date
- Tags cam gokart mikuni 22mm carburetor predator 212 cc
My #1 supplier for cams is Small Engine Cams (Isky Racing Cams).
Tim Iskederian knows a thing or 2 about cams.
Give him a call and let him know what your build consist of.
The Black Mamba Jr is a VERY strong cam for daily drivers, trail busters, ridge runners, mud hole stomping builds.
It can be used as a drag race cam, but he's got much better custom cams for drag racing. The complete build has got to be built to handle those drag cams, for them to work as they were designed for.
The BMJ cam works much better then ANY cheap, junk $50-$65 cam you will find, ......there's no comparison.
It's has fast aggressive ramps, closes the intake valve very early, builds power quick, hits hard from idle to whatever rpm your build can handle.
Only needs #26 springs and stock valve train.
It's gotta lope at idle, and needs 2000+ rpm to get a nice sound, smoother idle, and instant throttle response. Works really good with 2800-3300 rpm stall. I run 3000 with mine.
Your build with the ported pred 212 non hemi head, would work good with the BMJ. That head's got a big chamber, 21-22cc, so you should have around 9.5: CR, depends on head gasket thickness, flat top piston, and piston to deck height.
A head with a small chamber will have more CR, but the BMJ will be happy and have no problems working with 9.5:1 engines.
If these engines came with the BMJ cam from the factory, cam manufacturers would be outta business and sprocket sales would be out the roof.
https://smallenginecams.com/product/104482
Tim Iskederian knows a thing or 2 about cams.
Give him a call and let him know what your build consist of.
The Black Mamba Jr is a VERY strong cam for daily drivers, trail busters, ridge runners, mud hole stomping builds.
It can be used as a drag race cam, but he's got much better custom cams for drag racing. The complete build has got to be built to handle those drag cams, for them to work as they were designed for.
The BMJ cam works much better then ANY cheap, junk $50-$65 cam you will find, ......there's no comparison.
It's has fast aggressive ramps, closes the intake valve very early, builds power quick, hits hard from idle to whatever rpm your build can handle.
Only needs #26 springs and stock valve train.
It's gotta lope at idle, and needs 2000+ rpm to get a nice sound, smoother idle, and instant throttle response. Works really good with 2800-3300 rpm stall. I run 3000 with mine.
Your build with the ported pred 212 non hemi head, would work good with the BMJ. That head's got a big chamber, 21-22cc, so you should have around 9.5: CR, depends on head gasket thickness, flat top piston, and piston to deck height.
A head with a small chamber will have more CR, but the BMJ will be happy and have no problems working with 9.5:1 engines.
If these engines came with the BMJ cam from the factory, cam manufacturers would be outta business and sprocket sales would be out the roof.
https://smallenginecams.com/product/104482
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Brown Stain Racing -- do you work part time for NASA? You certainly are a wealth of information and all good. Enjoy reading your suggestions and wish I still went to the track to race, would be calling you weekly. Have a wonderful Christmas and may all of you win the lotto next year. Getting old but still can dream.
Hello Lizardking, Do you know if the shop down the street machines small engine crankshafts? What I mean is the shaft ends that are 1" and need to be machined down to 3/4" and a 3/16" keyway added. Many of us live in the snow belt and have access to inexpensive 5hp Tecumseh engines, but most of the time, they don't have 3/4" crankshafts. Any help would be appreciated. Thanks in advance.
Herman -- if it is a 5hp engine what crankshaft do they have??? The good thing about Tecumseh is the crank is not hardened so it is easy to machine but I would like to know what size you are talking about. If it is a 1" then it most likely is NOT a 5hp engine. What ever the size of the crankshaft it has to be at least 2.300 long. Anything shorter than that it is not worth doing since it will not support a clutch or a t/c. Just something to think about before you turn it down.
Jim, I'm sorry, I forgot to say that the engines come off of snow blowers. The crankshafts are over 3" long.
I've had three of these crankshafts machined in the past and they work well.
I have considered a 1" torque converter but it will not fit the crankshaft because the keyway is not machined the whole length of the PTO.
Thank you for your reply and input.
I've had three of these crankshafts machined in the past and they work well.
I have considered a 1" torque converter but it will not fit the crankshaft because the keyway is not machined the whole length of the PTO.
Thank you for your reply and input.
Yupp they can be cut down.. I had one on a 12hp tec cut from 1 1/4 to 1”
Guy told me no reason to disassemble the engine but it made it easier for him. He had a Harley engine on the stand running and he just made a hold for a cutter bit and milled the Harley crank snub down that way. Said it would have also worked for my tec.
Guy told me no reason to disassemble the engine but it made it easier for him. He had a Harley engine on the stand running and he just made a hold for a cutter bit and milled the Harley crank snub down that way. Said it would have also worked for my tec.
You wouldn’t have to worry about making or even finding a cutting bit. If you find a confident shop owner they know what to do. For me a 1 1/4 crankshaft being milled to 1” cost me $40 but that was with the crank out of the engine. It doesn’t matter crankshaft in/out of the engine getting one milled for anything less then $80 is a deal!
Jim, Thank you for your offer to cut the crankshaft. I will call you in a short while.
To answer your questions;
These 5hp Tecumseh crankshafts are not hardened in the PTO area.
Typical diameter is 1", some are stepped to 7/8" on the end.
Original keyway is 1/4" but not from outer end of PTO, so you can not install a 1" pully, torque converter or clutch with a fixed key inside the bore.
To answer your questions;
These 5hp Tecumseh crankshafts are not hardened in the PTO area.
Typical diameter is 1", some are stepped to 7/8" on the end.
Original keyway is 1/4" but not from outer end of PTO, so you can not install a 1" pully, torque converter or clutch with a fixed key inside the bore.