Predator 212cc/Hemi Upgrade ?s

[LSCustoms]

Also watch E85 it is not the most user friendly...it can gum things up, and may need more maintaining than gas.
Depending on the mix.

Well, what I "was" going to say is Sounds like pump gas to me. And if you do end up with some insane, non-pull start compression ratio, you can mix race gas with pump gas, and there are on-line calculators to compute theoretical octane ratings.

next time, Sir, do not hesitate to post in one of my threads, your opinion is more than welcomed!

No where in your data do I see possible numbers on final compression ratio.

You won't see any fuel savings in cost with E85. You'll end up burning more- in some tests I've seen a 20% increase to maintain the same AFR as with race gas.

There is also some data out there from folks having aluminum oxidation within their combustion chambers as a result of burning it. That guy saw a 3% power increase with the E85 on the dyno by the way.

the above advice, along with the pm from Dave and speaking on the phone with Russell, has forced me to change my mind on the carb choice... I cannot be arrogant and ignore logical reasoning... I had ordered the carb and head, but was able to call and change the order to GAS on the carb... less potential complication for me at this point (and i am familiar with regular and race gas)... the extra money $10 to convert to e85 was credited toward and extra set of 26lb springs, so that it did not complicate the payment i had already made... i will have to sell these, or add them to the new take of hemi head (until i figure out what to do with it)...

 

[LSCustoms]

hopefully the last/ish order I will need to make, before i try and sell some unnecessary parts to help lower the total spent and clean up the budget goal.

following parts from NRRacing:

-Genuine Honda GX390, GAS, race prepped (but choke installed), stock bore, $49
-Racing Head, fully ported Predator Hemi, milled .080, 26lb springs installed, aluminum retainers and split keepers, stainless valves 28mm/25mm, 3 angle valve job, complete head including valve cover (everything but the head gasket and push rods) $239
-aluminum choke holder $2.50
-shipping $18
-totaling $308.50 shipped

GrandTotal: $914.11
Left in Budget: $85.89

 

[LSCustoms]

GrandTotal: $914.11
Left in Budget: $85.89

Initial Evaluation:

Money is Time (in that the more you spend, the more time you save)
Patience is Money (the more you have the more money you save)

most of the time, I'd rather spend more time and less money!

I have to find a balance with some of the stuff i do and have more patience, but such is life and is no big deal!

More than likely, with a little more PATIENCE(waiting for answers/advice/research), I could have saved budget/money in the following areas (looking at the cost:gain factor):

-Wiseco Piston, wrist pin $108.95
-shipping $20 (give or take a few, could have got an actual total parts list together before making one order and wouldnt have paid double shipping on some items)
knowing the carb i wanted before ordering, now having extra springs $10
-cost of life experience/total : $138.95

grand total could have been: $775.16
budget left could have been: $224.84

As i have wasted more money on sillier things in the past, moving forward... the smile on my familys face, just one smile, PRICELESS (of course)

 

[youngengines]

Hi LSCustoms,
The black mamba cam works great in the hemi headed predators. You will not be disappointed in the power it makes.
Tim

Remember guys, the predator build I just did has a Black Mamba in it. I don't suggest anything I wont run. I just got 3 cams from Tim today!!

 

[LSCustoms]

Remember guys, the predator build I just did has a Black Mamba in it. I don't suggest anything I wont run. I just got 3 cams from Tim today!!

it runs GREAT in my other motor too!

 

[LSCustoms]

got some parts in

 

[fistfullabar]

got some parts in

nice got the goodies now slap that bad boy UP and RUNNING

 

[LSCustoms]

nice got the goodies now slap that bad boy UP and RUNNING

will get to it, soon as i get the wifes kart motor swapped in... hopefully this weekend... head and other parts should be here beginning of next week... all other parts have already been shipped and are enroute...

 

[LSCustoms]

GrandTotal: $914.11
Left in Budget: $85.89

This post will contain any parts sold and budget recovered from take off parts:
-sold stock Piston and extra 26lb springs, net $30ish

GrandTotal: $884.11
Left in Budget: $115.89

 

[vwfan79]

Everything looks good with your build but I have one question, and maybe its answered and I just missed it, your using a 390 carb with arc adapter is your motor plate on an angle? The reason I ask is that unless they have a new adapter the one I got is ment for kart racing where the motor is at 15 degrees. On a flat surface it drowns the idle circuit and the motor doesn't want to idle good if at all. On a flat surface my motor will only idle on half choke, but once I get going it screams with the 390 carb. I have a similar build as you and will be seen in a future bike build, my specs are hemi block .010 head gasket Honda 14cc head all port matched ss valves with locks and retainers 26# springs 1.3 rockers black mamba cam arc rod 390 carb with air filter rlv header, I feel like I might have missed something but you get the idea. Anyways great thread love all the detail.

 

[LSCustoms]

Everything looks good with your build but I have one question, and maybe its answered and I just missed it, your using a 390 carb with arc adapter is your motor plate on an angle? The reason I ask is that unless they have a new adapter the one I got is ment for kart racing where the motor is at 15 degrees. On a flat surface it drowns the idle circuit and the motor doesn't want to idle good if at all. On a flat surface my motor will only idle on half choke, but once I get going it screams with the 390 carb. I have a similar build as you and will be seen in a future bike build, my specs are hemi block .010 head gasket Honda 14cc head all port matched ss valves with locks and retainers 26# springs 1.3 rockers black mamba cam arc rod 390 carb with air filter rlv header, I feel like I might have missed something but you get the idea. Anyways great thread love all the detail.

thanks...

as far as idling issues, etc., I have to verify this again, but was told to use the Insulator that Arc says to take off (and you may need an extra gasket if this is needed)... it may have been to use the 390 insulator, but i have to re verify that info (im a little tired, I cant remember off hand)... but for sure, i know there was a suggestion given to fix that issue, if I had it...

 

[vwfan79]

Well if you run into this issue and figure out a fix for please post it as myself and others would be interested. My motor is going on an angled motor plate so I should vw alright but when first built it was on a flat one and was kind of annoying.

 

[LSCustoms]

Well if you run into this issue and figure out a fix for please post it as myself and others would be interested. My motor is going on an angled motor plate so I should vw alright but when first built it was on a flat one and was kind of annoying.

will do, I was given this information from Russell (NR Racing)... I had called to change the carb from e85 and while talking to him, he mentioned it... and said he had hear this issue a few times (with the arc short plate) and that should be able to fix it...

 

[ole4]

Just a FYI the two motors I have with the Black Mamba both had issues with pull starting. On my two cams the base circle was reduced about .100 but the compression release tang was not changed. It wound up that cranking compression was 20PSI. If you used a electric starter it would fire up just fine but no-go on pull starting. When you are assembling the engine just watch the ex valve/lifter and see how close to TDC on the compression stroke it goes before the exhaust valve closes. On mine it did not close till near TDC. After modding the tang by squeezing it with a large waterpump pliers all was fine and I had about 60 lbs of compression. If base circle is reduced by .100 the compression release should be reduced by .050. You may want to measure the stock cam base circle and height of CR VS the Isky cam.

 

[youngengines]

Just a FYI the two motors I have with the Black Mamba both had issues with pull starting. On my two cams the base circle was reduced about .100 but the compression release tang was not changed. It wound up that cranking compression was 20PSI. If you used a electric starter it would fire up just fine but no-go on pull starting. When you are assembling the engine just watch the ex valve/lifter and see how close to TDC on the compression stroke it goes before the exhaust valve closes. On mine it did not close till near TDC. After modding the tang by squeezing it with a large waterpump pliers all was fine and I had about 60 lbs of compression. If base circle is reduced by .100 the compression release should be reduced by .050. You may want to measure the stock cam base circle and height of CR VS the Isky cam.

I have ran into that as well,(don't remember what cam it was though). Good point. I also thought one was too high and bent it down too much, it would want to rip your arm off..LOL

 

[ole4]

I still had my stock cam so I tried to match it. I had a hell of a time squeezing it and finished it with my cremel. Still only had 60Lbs compression but now it started OK.

 

[youngengines]

I tapped mine down with a hammer, them polished it with a sanding roll. I think it had a round 80lbs then.( and like 235lb using a starter)

 

[LSCustoms]

Just a FYI the two motors I have with the Black Mamba both had issues with pull starting. On my two cams the base circle was reduced about .100 but the compression release tang was not changed. It wound up that cranking compression was 20PSI. If you used a electric starter it would fire up just fine but no-go on pull starting. When you are assembling the engine just watch the ex valve/lifter and see how close to TDC on the compression stroke it goes before the exhaust valve closes. On mine it did not close till near TDC. After modding the tang by squeezing it with a large waterpump pliers all was fine and I had about 60 lbs of compression. If base circle is reduced by .100 the compression release should be reduced by .050. You may want to measure the stock cam base circle and height of CR VS the Isky cam.

I will check, when cam gets in... thanks for the info...

 

[ole4]

Just for reference the picture 2nd from the bottom is CR on stock cam bottom pic is the black mamba before mods. If you look close you can see black mamba has base circle ground down compared to the stock cam.

 

[Boogie Man Ryan]

I talked to russ about the safe issue regarding the arc adapter. i told him the air bleed on the back of the 390 carb was un able to vent with just the adapter.... you can do two things... One is run a insulator...and you still at a 15 deg angle, or you can jb weld the back of the carb, and drill the air bleed on top/side of carb with a small nipple to vent...this will allow no insulator just gaskets and give the true stock appearing look. If you get nr racings 390 to gx200 adaptor it all ready had the insulators vent areas built in...and will sit at the angle you need... if you go this route the carb is nowhere near as aggressive as the short arc adapter..it feel like a 22mm at best... the first way at the 15 angle did idle and surge...but as soon as you got full throttle it was like warp speed:laugh:...just food for thought.