Old style head on new style engine?

[TankforGod3]

Aight bros After poppin off the valve cover on my hemi predator and seeing the rocker arms on it I was kind of sad that i couldn't find that style in 1.3:1. I wondered if the old style predator head would fit my engine, or even a smaller gx series head, but I read somewhere that the old style predator is different than the hemi head. I could have possibly dreamed that but anyways would the old style head fit my motor and also would a gx160 head fit the hemi. I would like that very much as my go kart has to compete against a gy6 with a cdi box and it cranks about 14k. After I find a better head I'll will be getting an isky black mamba JR and some springs to set a "gap" in the competition.

 

[Camjamsdad]

Yep the other heads will fit your block. You also have a flat top piston in there. I'd go with the big mamba over the junior since you want every bit of power you can get.

 

[ole4]

yes the clone or honda will fit. the hemi predator uses the same locating as the clones unlike the other predators that are larger. you will need to use clone pushrods.

 

[TankforGod3]

what length pushrods?

Alright thanks so ill get a gx160 head, if I get the head for gx160 what length pushrods will I need. I plan on chromoly's but with the different head and 1.3:1 rockers would stock length work or would i need a specific length.

 

[TankforGod3]

or even better

Instead of a gx160 head I'm looking at a 14cc clone head which a good bit smaller than the stock 22cc head what length of pushrods would i need for that head and it's on nrracing if you want to check it out

 

[ole4]

stock length clone pushrods should work depending what rockers you are using. Are you using the stamped yamaha 1.3:1 or raceseng rockers? If you use billet lifters they are a different length and you need different ones. If using the stamped 1.3:1 rockers stock length clone pushrods should work.

 

[Prowler08]

There are a few that make rockers for the Hemi... Some make,the Honda Raceseng rockers work in the Hemi.
I just use gx160 lifters...
Not all billet lifters require different length push rods...FYI
The lifters in the Predator are a different length than the Honda/clone.

If you use stock length lifters, and stock length push rods from a clone or Honda you do not have to use cut to length push rods...
If you do not mill the head... You would be find with the Honda/clone valve train... With 1.3 rockers and the Mamba cam...
But, if you do make sure you get the proper springs...

Many ways to skin a cat...

 

[TankforGod3]

all right thanks and Im guessing that with a .045" head gasket and a 14cc head Ill roll on down the road with about 11:1 compression so it works for me thanks guys

 

[rmm727]

Instead of a gx160 head I'm looking at a 14cc clone head which a good bit smaller than the stock 22cc head what length of pushrods would i need for that head and it's on nrracing if you want to check it out

gx160 heads are usually 14cc.

 

[Norcalputput]

14cc heads need a bit of work to get the flowing for high rpm operation
But if your handy with a die grinder you can un shroud the valves and clean up the ports in a few hours and don't go hog wild on the ports velocity is important
^^^^^^^^
Camjams right get the regular black mamba not the jr your going to need the duration isky will set you up
Think he has a kit cam, springs, oil


Sent from my iPhone using Mores code

 

[TankforGod3]

I'm not sure I want to do the 14cc head because according to the compression sheet on nrracing with the 14cc head the compression would be about 11.8:1 I really dont feel great great running the stock piston at that compression but heck I might. The other thing is I'd say it'd still run on pump gas but if it don't then I would be screwed because I cant get any high performance stuff around here.

 

[Prowler08]

Stock piston is fine... 12-1 comp on pump gas is fine...
If you get a bit of detention, add a bit of xylene or toluene to bump it up to 97-98 Oct.
Can be bought at any paint, hardware store...

 

[Camjamsdad]

You're not doing anything that hasn't been done before. In fact you chose a fat head gasket compared to the .010 many use.

Give Tim at smallenginecams a call and he'll suggest what he thinks is best. Chance is maybe he has a custom grind for what you want.

 

[davidlamb78]

I'm running a 14cc head with a Dyno Cams CM cam. (This is on my blue clone, not my hemi.) I think its a 275 lift, but not sure. I'm running 18 lb springs, but I'll bump up to 22 or 26 lb srpings when I get new valves. My carb is a cheater carb from Dover Power. I can touch 8000 with my set up. I am running the 20 over billet rod with a FT piston, and it's been fine. I'm guessing your stock piston will work fine. There is a fair amount of test and tune with these. Certain setups will produce more power than others, and it takes some mixing and testing to really find what works. I'm really happy with my setup right now, but I only rip through the neighborhood with mine.

I agree, the Mamba Jr. has a lower power band, so you may want to go up to the Mamba. I think the regular Mamba pulls hard up to 8,000, but don't quote me on that.

 

[TankforGod3]

when I was looking at the compression sheet it says with the 14cc head and a .010" head gasket the compression is 14.1:1. With the 18cc head it is only 11.4:1. I think for now I'll be going with the 18cc head unless I read the chart wrong or something like that. I'll make my motor even badder than it is now one way or another.

 

[Prowler08]

Look closer... If you have 0 deck height with a .009 gasket you would be 14-1 comp.

I would think with 0deck height your valves would smack the piston with a thin gasket.

 

[TankforGod3]

The deck height isn't quite zero but its like .003" so I went with zero as it was the closest. I completely forgot about valve clearance thanks for reminding me but I'm sure if I was installing the head I would check. For you other guys I'm going with the Black mamba (not JR) as my low end game now is amazing. (I can outrun the gy6 go kart that has a 9:1 reduction in a drag race)

 

[youngengines]

Look closer... If you have 0 deck height with a .009 gasket you would be 14-1 comp.

I would think with 0deck height your valves would smack the piston with a thin gasket.

0 deck with a .009 gasket would most likely blow up, from the piston hitting the head. I never go under .020 piston to head in a modified build, and prefer .025..JMO

 

[SnakePliscan]

Deck height?

0 deck with a .009 gasket would most likely blow up, from the piston hitting the head. I never go under .020 piston to head in a modified build, and prefer .025..JMO

Weird... Ive been lead to believe the Hemi comes stock with the piston 0.020" down in the hole @ tdc
This guy is sayin he has near 0.0 so what gives?
I didnt read here about a +0.020 rod, how is this thing being measured?