i blew two stock rod predators without ventilating or opening a window in the block. the rods ends came apart into three pieces, but didn't touch the block....lots of metal bits in the oil and all over the inside, but it didn't touch anything else. btw...i did scrap the crank and the bearings because of the metal shavings...
Holy Moses Cam
- Thread starter W5R
- Start date
Much bigger engine than a 200-212 clone also lol.
And mikey, are you torquing the rod bolts with a torque wrench? 2 rod ends breaking thee same way for you appears to be more of an installation error, if not by you then possibly at the factory.
two different stock rod motors (predators) with a high lift cam (356) twisting above 7 grand...they just don't like that! this past season was home built clones with arc rods....not a lick of problems reaching and staying in the high 7K to mid 8K rpm range....
both engines were opened up and rod bolts torqued....made sure of that....
both engines were opened up and rod bolts torqued....made sure of that....
Why all the hype of turning all of these rpms. This happened in nascar with the invention of the spintron and nearly over night adding 1000 rpms to the engines. Heck we even built cranks that were built exactly like a two stroke crank and turned well over 10000 grand. But the engines were just spinning not making any real power the same thing the clones are doing on a quarter mile plus track while only loosing a couple of hundred in corner. Seen this happen with the flat heads and the 96-3 cam I believe. Remember horse power is for show, torque is for go.
Now, was that a polite thing to say. LOL
in mathematical terms, one horsepower is the power needed to move 550 pounds one foot in one second. torque can be generated without moving an object. however, when it does move an object, it then becomes "work," and this is what most people think of when they think of torque (usually in terms of towing). the more torque produced by an engine, the more work potential it has. torque is the base number for work, and power is the rate of doing more work. the more horsepower produced, the more torque potential there is from the engine. there's not a lot of work needed, in a relative sense, to push a kart forward, so less work is accomplished, leaving more power for speed.....not my words, just what I found.....
looking at it from my point of view....you can't have one without the other....horsepower isn't for show...nor is torque for go.....you can't separate them that way....
just sayin!!!
looking at it from my point of view....you can't have one without the other....horsepower isn't for show...nor is torque for go.....you can't separate them that way....
just sayin!!!
Mikey Torque is tha amount of work capable, horsepower is the rate that the work is being done.
The more torque you have, the more work potential you have.
Torque is the force, power is the rate.
You do not have any horsepower from an engine without torque. In reality it is torque that moves the vehicle.
The more torque you have, the more work potential you have.
Torque is the force, power is the rate.
You do not have any horsepower from an engine without torque. In reality it is torque that moves the vehicle.
youngengines
Member
People say torque wins, but not if its at the wrong rpm's. I want torque, but I want it in higher rpms...
Hence the common statement "at that RPM they are just making noise"
Fortunate Son
New member
The ability to move the powerband of any engine comes from Cam timing events. The ability to advance or retard timing from the centerline. Something I wish we could do with existing cams that can be adjusted by the User to suit there application or situation. We did this all the time in my drag racing days.
Fortunate Son
New member
I may also add that Cam grinders probably don't want the user to have ability to adjust timing so you would have to have separate Cams for each application. If you could have the ability, you could do alot more with a single Cam.
The oil you were using could have possibly been the cause of that, or something could have been out of spec at the factory, even installing the rod at the factory without assembly lube or some type of lubricant to protect the engine on the first startup could have caused your problem. It is not the stock rod causing problems like that, or you would see a hell of alot more of them than you see now. Im with Dynodon on this issue, there is no reason to use anything other than the stock if you are keeping the engine at a reasonable RPM (6500 or less) and changing the stock rod when the engine is rebuilt or serviced. Its a $6 rod, there is no reason not to replace it when in doubt.
I agree with this, but there are ways to modify an existing cam(twisting), whether it is advised my many or not, it does work from what i have seen.
thanks guys...everything you've said is right. you can't seperate the two. but you will have a point where, like kart 43 said, you'll be doing nothing but making noise. everything has to work together inside a motor to produce the horsepower necessary to produce torque that will propel the kart forward. in our application, neither horsepower or torque is limitless, you will soon reach a point of diminishing returns...meaning that you will reach that point where you can't produce any more horsewpower to produce the torque necessary to move forward at a faster pace, you can sustain it, but you can't move forward faster than what you are already. if you can't produce the horsepower or harness the torque to move you forward, your nothing but a very expensive boat anchor.
but i digress....this is about the HM cam and what you can expect from it.
but i digress....this is about the HM cam and what you can expect from it.
I do believe Isky sells his billet cams with adjustable timing!
All we can find why the rod let go was it got hot to either fry the oil causing to seize to the crank, or the rod let go...
we speced and torqued everything and have do a lot of these engines...this is the first one that ever did that?
alvin l nunley
Site Supporter
I call this a truism. It sounds so neat and appears to make so much sense, it must be true. My favorite is, “torque off the corners and horsepower down the straight.
The fact is; compare 2 torque curves and you’ll find, at any given RPM, the engine with the higher torque curve is making the most horsepower. Torque X RPM / 5252.1 = horsepower.
If, with the same gear ratio, you’re turning more RPM, you’re going faster. If you add a tooth to the axle, you need to turn about 100 more RPM to be going the same speed. I say “about” because, the needed increase in RPM will be different depending on the gear ratio.
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory.