Box Stock

Hemi vs none hemi on predator

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woodrat1994

New member
Please don't bash me I'm new trying to learn and understand can you run a hemi predator against non hemi predator in the same class
 
I haven't seen a difference performance-wise in box stock, we run them all together. Just because a head is a hemi head doesn't mean it's a performance head. The non-hemis have a fine looking cylinder head.
 
we ran Corinth Ms this weekend first time we ran a "box stock" class rules were small pipe with muffler, stk fuel tank or top plate... chain guard, $150 claim... they ran 3 classes 1 for under 15yo 1 for med one for heavy... about 40 karts total... and non of the winners were hemi engines... only saw one non hemi block but the winners all had non hemi heads... we sat on the pole sat. with by far the fastest kart... by sunday in the race we were 1.2 seconds faster... finished 2nd sunday after starting in the rear and no cautions... the leader had checked out but our lap times were faster... but again the winner had a non hemi head on a hemi block... just like us... I got some help from the guru of these things here friday... so friday night I did some work following his advice and made the changes sat, morning at the track... and never looked back...
 
When we first started running the Predator class we bought a non-Hemi because that's what our store had. Once we got to the track we heard about the Hemi, and that "they were better", so when our store got some in we bought one. Didn't notice any significant difference between the two - including on the stopwatch.

Now realize that our rules are box stock - original muffler, original airbox, governor hooked up and working. You could run the original fuel tank or a top plate, but now they say original fuel tank only. Drill holes to vent the gas cap, and disconnect the oil sensor. No aftermarket pipe, and not supposed to put a non-Hemi head on a Hemi block (but they haven't actually published a rule stating that).

We happen to have two other Hemi engines because we were going to put another kart together, but they too run about the same lap times as our first two engines. Can't tell any real advantage over a non-Hemi (in completely stock form) so I wouldn't worry about buying another non-Hemi if I needed another engine and that's all the store had in stock.

However, I'm told by guys who claim they can build me an "undetectable modified Predator" that the hot ticket is a Hemi block with a non-Hemi head (but only certain non-Hemi heads - there are several different part numbers)... if your rules allow that then that's probably what you'll need, but your budget class won't stay budget for long...
 
So how do you tell a hemi block from a non hemi block ?? I was under the impression the head and valve cover were the difference .
 
here is the quick run down... hemi version has a flat top piston, same rod, same wrist pin... same bore, same stroke, different taper on the crankshaft for the flywheel on the hemi, different push rods shorter on hemi, same lifters, hemi cam journals are the same as the clone. side covers do not interchange because of the different cam journals..

NON hemi.... dished piston, same rod& wrist pin same bore & stroke... same crank journal size... BUT different taper on the crank flywheel... accepts clone type flywheels... cam journals are bigger... so cams do not swap... longer pushrods, same lifters...

yes many many many heads for the non hemi... some have automotive type retainers some have 5mm stems some have 5.5mm stems, some valves are bigger... some heads flow much better than others... some ports are huge compared to others...

carbs exhaust tins ect pretty much all interchange... but it gets better... there is the Ducar hemi which is a better "predator hemi" and now BSP has a 212cc that has some interesting options... to get the best "box stock" engine takes parts from several to make one (imho)... there are guys on this forum that know far more than the rest of us ever will about these engines and what will and will not work and what they need to go fast...

these are not precision built at the factory... they are 500-1000hr service life 3600-3800rpm tiller engines.. there is much to be gained just by making sure the parts fit together as they should nice and smooth...
 
Clone and non-hemi flywheels aren't the same taper. A non-hemi flywheel on a clone will knock out the oil seal. Trust me.
 
I have been running clone billet flywheels on non hemi cranks without issue... I lap them on and i see good even contact... am I wrong?
 
The dowel pins are different from the non Hemi to the Hemi so how are they getting away with dowel pin situation
 
I do not need any. My question was how are they getting away with changing the heads when the dowel pins are different
 
Don
I would type what I think but I know it would be deleted.
Basically you got all these A holes that can’t drive or set up a kart so they got to cheat to win. Just to destroy a class that is for beginners. Then you have tech that doesn’t look.
 
Marvpower said:
Don
I would type what I think but I know it would be deleted.
Basically you got all these A holes that can’t drive or set up a kart so they got to cheat to win. Just to destroy a class that is for beginners. Then you have tech that doesn’t look.
Click to expand...

if you don't know the facts you should really not say anything why open your mouth and confirm what you don't know... where we race this happens to be legal in our class... now you have confirmed that you speak before you know squat and makes you look exactly like what I think you are..
 
don
what you have to know is predator rules are not uniform from track to track... no one runs clones at the tracks we run... it's a 212cc rule... a 10.8 spring and cam rules... kinda sad that others chime in when they know not of what they speak and then they pass judgment might as well give them a sign....:p
 
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