Predator 212cc/Hemi Upgrade ?s

#1
Did as much research as I could and still had a few questions to clear up...

I have a couple of "carts" with products in them and want to make my order within a day or so... those that have upgraded this motor, please feel free to give your opinion or advice...

am i missing anything, or is money best spent elsewhere on anything? just want to do anything i can, without wasting money and without having to machine the block

on the Hemi headed predator:
1- arc billet flywheel 6626 (with 8 degrees timing advance) (ARC)
1- arc billet rod 6254 (but will go +.20 if piston is in the hole) (ARC)
1- 26lb spring set (smallenginecams)
1- isky black mamba cam (smallenginecams)
1- 27mm stainless valve DJ-1127 (is this stock size?) (ARC)
1- 25mm stainless valve DJ-1121 (is this stock size?) (ARC)
2- HD retainer kit, w keepers DJ-1047 (?) (ARC)
2- Chromoly Push Rods (not sure on length ???, same as old style?)

1- port work and mill on stock head (??? youngengines?)
1-aftermarket carb (???), e85 ??? unleaded gas??? ethanol???
or
1- etube 140 and jets (will determine which jet based on test and tune) ???

research has revealed that I cannot use a larger spring than a 26lb, without cutting the pockets? cannot use 1:3 ratio rockers? push rod lengths are different?

am I missing anything, is anything a waste of money for this motor...
 
#2
for this project... no rules to follow, just want a nice running engine/performing bike... the current old style predator in the bike, performs well, but would like to get more outta this motor...



14t clutch sprocket/54t axle sprocket, 13.11" ish rear tire height
 
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#5
The cam can rev to 8000 but you must make sure your seat pressure is at least 26lbs. If you get chrome moly pushrods you need to get the ones that you cut to size. I don't know if anyone has the right pushrods for them yet. you may want to go with the cheap mikuni carb as it flows much more that the stock type carb.
 
#6
The cam can rev to 8000 but you must make sure your seat pressure is at least 26lbs. If you get chrome moly pushrods you need to get the ones that you cut to size. I don't know if anyone has the right pushrods for them yet. you may want to go with the cheap mikuni carb as it flows much more that the stock type carb.
thanks, ill measure the stock push rods and/or see if that number is floating around too

the cam comes with the 26 lb springs, but i see your point and may have to double check that the actual seat pressure is 26+ lbs? maybe with the head work, i can have whatever needs to be done to put bigger springs and go slightly bigger cam (just not sure and trying not to over complicate/budget it)...

if i were to buy a carb... would rather buy one modified for a different fuel type, if it squeezes any more performance over unleaded...

still researching to see if there are any threads out there like Barry's old style predator thread, where he actually posts the results from mod and dyno work... cant find any such information... if i follow the results off of his old style predator thread, im thinkin the performance gain should be comparable or better with this motor...
 
#9
most all info or results I find and whatever I end up doing, will go in this thread... as it has been difficult for me to find much on this motor (in thread/documentation form). especially for people who are intimidated to just buy parts, test/try on their own... I will include prices I paid for what ever it is (as I buy them)... and their will be pics and video... as this motor is going on a project bike, some of the same pics and video will be in that thread, but less detail info...

i took tons of pics, when i modified the other predator, but there are tons of threads/vids showing governor removal etc... i will upload good documentation, of whatever i do, component delete, motor install, etc, on this motor... because.. well, this is my thread... lol...
 
#10
My budget is to be under $1000, if possible, when all said and done with the upgrades (to make this actually run, carb, throttle plate, etc).. I wanted to do only what is necessary to achieve my personal goal with this motor. which is to gain the highest possible hp/tq or in the highest area, without having to machine the block for a stroker crank or bigger piston. To do that would blow my budget almost instantly.

I will not edit what I buy, even if a mistake was made, or somehow i end up over the budget :confused:... just so a person new to small engines (like myself) can see what I went through... seeing a thread like this, would have saved me a ton of headaches... thanks to guys like youngengines, I am quickly becoming more comfortable with choices, without buying my own dyno machine etc...

this is where I am at so far and what has ALREADY been ordered or obtained:

-Harbor Freight Engine 60363, Predator 212cc, Hemi-Headed Version $97
-ARC 6626 Billet Kohler CH270/New Predator Flywheel $100
-ARC 6236 Billet Rod (3.595" X .490") $83.95
-11132P94 Wiseco Piston (2.756" X .640") $89.95
-ARC 6521 New "Short" Heavy Duty Wrist Pin $19.00
- DJ-1146-P ARC Top Plate/Throttle Station (For Hemi-Head) $25
-Walbro FPC1-1 Fuel Pump (New Style, good up to 25hp) $17.50
-Autolite Spark Plug AR3910X, $7
-Misc (Shipping) $9

Total so far: $448.40
Left in budget: >$551.60

will sell any take off parts I can, to bring the overall money spent down to as low as possible for my budget...
 
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#11
Still need to figure out:
1. The cam I wanted to go with, initially, is the Isky Black Mamba ($65 with 26lb springs and racing oil). will running a larger cam profile (with my mods) be more beneficial and increase hp/rpm? pros/cons? Black Mamba .275" LIFT 246 DURATION @ .050" 108 L.S.A. Versus, lets say a .310" LIFT 246 @ .050" 108 LSA, my spring choice will depend on this...

2. NRRacing is the only company I found, that sells a Race Port/Modded Hemi Head, the only problem/issue is that this entire motor cost me $97. the head through NR, with the mods I would want, will be $247 shipped. Is the head worth the purchase and selling my stock take off, to offset the cost. The head is complete, with the exception of not having pushrods, or head gaskets:
Fully Race Ported and bead blasted
Milled to increase compression (.080)
Lightweight Stainless Valves (28mm/25mm)
Aluminum retainers and Split Keepers
3 angle valve job
Choice of single or dual springs (55lb springs add $30)
valve cover, rockers, etc

3. Exact Carb Choice... Where to buy and specs... E85 vs METH (and pros/cons), which gas will produce the most hp, or best HP/Tq
 
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#12
I am about to build a similar motor to yours. But because I could not fit the salsbury TQ and am now using a comet 30 series I may go with the black mamba JR. My drag bike with a black mamba and a salsbury 330 goes best when I set it up for a 3800 rpm engagement. I can't do much with the 30 series and it engages around 2200 where the black mamba is not making much power. Before BOB's 4 cycle went down there were a number of threads on the hemi and in general it made a bit more top end power than the regular headed motors but a bit soft out of corners and less low end. I plan to weld up my head to make it like a fast burn chamber to raise compression and am thinking for this build will go for low end grunt. Also it looks like you are going with the long rod and weisco piston. You do know that the Hemi motor has a good lightweight flattop piston already in it and many reported that the piston was in the hole .010 or less in some cases. That would save you some of your budget. I always do my own heads and will soon flow the stock head to see what it flows. You may want to wait to see the results before plunking down cash on the nr head. You could just radius the short side slightly and a 28mm intake will work on the stock seat according to some on the 4 cycle forum and it comes stock with a 27mm intake. Just my thoughts. I will post pics when I get into the motor.
 
#13
I am about to build a similar motor to yours. But because I could not fit the salsbury TQ and am now using a comet 30 series I may go with the black mamba JR. My drag bike with a black mamba and a salsbury 330 goes best when I set it up for a 3800 rpm engagement. I can't do much with the 30 series and it engages around 2200 where the black mamba is not making much power. Before BOB's 4 cycle went down there were a number of threads on the hemi and in general it made a bit more top end power than the regular headed motors but a bit soft out of corners and less low end. I plan to weld up my head to make it like a fast burn chamber to raise compression and am thinking for this build will go for low end grunt. Also it looks like you are going with the long rod and weisco piston. You do know that the Hemi motor has a good lightweight flattop piston already in it and many reported that the piston was in the hole .010 or less in some cases. That would save you some of your budget. I always do my own heads and will soon flow the stock head to see what it flows. You may want to wait to see the results before plunking down cash on the nr head. You could just radius the short side slightly and a 28mm intake will work on the stock seat according to some on the 4 cycle forum and it comes stock with a 27mm intake. Just my thoughts. I will post pics when I get into the motor.
i saw where someone put they used a 28mm in the stock with no issues, just wasnt sure... also am aware the stock piston is good, but may have slightly more advantage as the weight of the wiseco is less and with the combo, the stroke would be more? and then the better wrist pin? when i added up the parts to buy for the head, with the stainless etc., it came up to roughly around $110 or so... the price difference would be around $147... i can prob have the head work done for around $100 (would want this done professionally, or by an experienced builder, so that it isnt just cleaned up, but flows as best as possible)... not so comfortable doing the head myself (milling .080, valve job, etc), to get the best result...

so i was looking at the net difference of $47... given the fact that it comes with a complete head, valve covers (pretty much everything to bolt on, aside from the push rods and the head gasket), I figured that if i dont swap the head over to the wifes old style predator, i could sell it to make up the difference, as some would prob pay for just the head... bolting it on the wifes motor would be a good improvement as it is...

just explaining my thought process, to see if that makes sense vs trying to do this headwork myself...
 
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#14
Your logic is good and 247 shipped is a good price. And you could sell your old head. I would give you 50 bucks for the hemi head if you don't use it on your wife's kart. The long rod and weisco piston do not change stroke that is a function of the crank. The longer rod has other advantages like less rod angularity and longer dwell time around TDC. For me I plan on a billet flywheel and rod, stock piston a cam maybe the mamba Jr. the cheap mikuni and one of my homemade stainless headers.
 
#15
Your logic is good and 247 shipped is a good price. And you could sell your old head. I would give you 50 bucks for the hemi head if you don't use it on your wife's kart. The long rod and weisco piston do not change stroke that is a function of the crank. The longer rod has other advantages like less rod angularity and longer dwell time around TDC. For me I plan on a billet flywheel and rod, stock piston a cam maybe the mamba Jr. the cheap mikuni and one of my homemade stainless headers.
ok... thanks for the clarification on the longer rod... makes since... that $110 piston and wrist pin upgrade, is now a lesson learned... I know it is lighter though, so hopefully that somehow makes a difference along with teh angularity, etc... good info...

i will keep your offer to buy the head, in the back of my mind, after/if i get the new head in my hands... wouldnt want to sell it and then something go wrong with the order...

waiting on a response from isky on a few questions i had about cam options, then will order the cam and make a final decision on the head... I would love to save money having the head done somewhere, but it would have to be quite a savings for me to go a different route and it would have to be for a head that would perform the same or better than the NR (same options and mods)...

for the carb, im leaning toward e85 (genuine honda, modded) for the price and availability, but still looking at options..

the other choice would be the Dover SA meth carb that youngengines rec. to me, but there is a back order on this and i intend to move pretty swiftly on this project...
 
#16
BM karting...has a head milled either .02 or .065, P&P, and a S/A carb on their site...
Head with work done $90.00, and a S/A carb for $70.00

FYI
 
#17
You may want to call Tim. He is a great guy but very busy and has a hard time keeping up with email if he happens to be getting a lot of them. He answers them in the order he get them. He does not always pick up so keep trying every so often. Once you get him he will talk till all your questions are answered. Love his cams!!! Great prices as well.
 
#18
BM karting...has a head milled either .02 or .065, P&P, and a S/A carb on their site...
Head with work done $90.00, and a S/A carb for $70.00

FYI
thanks, i checked their website out and i didnt see a hemi head on the site... saw the clone carb though and option for e85... but NR has a genuine honda/modified carb with same option (e85 or alky) and a hemi head, complete (if i sell the existing head, would have spent a net $100 labor, for a built head and the above listed mods)

You may want to call Tim. He is a great guy but very busy and has a hard time keeping up with email if he happens to be getting a lot of them. He answers them in the order he get them. He does not always pick up so keep trying every so often. Once you get him he will talk till all your questions are answered. Love his cams!!! Great prices as well.
yes... i like the black mamba... gotta see if he does harley cams too (as i need a more aggressive profile for that as well)... i will call or fire up the harley and take a trip to his shop... i will wait till i hear from him, as i want to buy an isky cam for sure...
 
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