Open Animal Help

Orangeshovel

New member
Bout to start putting together a stroker open animal(gen5).

Thinking about using:
2.437 billet stroker crank
3.625 billet rod
2.756 piston

If i use the +.237 crank would a .340 lift cam or the .400 lift cam be better? Is the .400 too much? Also depending on which cam i decide what would be a good idea for porting and valve size? increase intake or exhaust or both? With that much lift what head would be best? Could i use a WF head or should i just find an aftermarket head?

Also are there any other stroker cranks for the animal besides the +.237 crank?

For this setup is roughly +.080 overbore enough?
 

Orangeshovel

New member
If I remember correctly, someone makes a .433 stroker crank....or did.
Yea i've seen past Bob's posts on the old site where multiple ppl were using a .433 stroker but I cant find one anywhere. I know theres the flathead stock (+.237animal) and the stock animal crank but could the flathead stroker (+.200) be used as a (+.437) animal crank? I didn't think the journals where the same size.
 

dwight80

New member
Yea i've seen past Bob's posts on the old site where multiple ppl were using a .433 stroker but I cant find one anywhere. I know theres the flathead stock (+.237animal) and the stock animal crank but could the flathead stroker (+.200) be used as a (+.437) animal crank? I didn't think the journals where the same size.
try lunati thats where my crank is from don't know what the stroke is but its big enough to where the oil slinger had to be milled off the rod. And the crank and rod dip thru the oil and sling the oil them selfs
 

metalmagic

New member
Exhaust valve/port flow only needs to be 65-70% of intake to be efficient.... U don't want them to big due to reversion
 

S. Fizer#24

New member
Thee ARC .200 stroker crank for a flathead makes the .433 stroker in the animal. Also all you need is the .308 lift billet cam from Dyno with the 1.25 roller rockers. Then send a head off or just buy one that has already been done with big valves. I built one a few years back and was awsome for what it was! I turned mine 9000 or 9200 all the time and never had a bit of trouble. Make sure to replace rod bearings and bolts every little bit. Only thing ever happened was I broke an inner valve spring. Put ARC 3HP Billet flywheel on it as well. Then a really good tilly carb. A HL360 or maybe even an HL 380 and a good candy cane pipe . But as far as the crank, call ARC and they'll fix you right up with everything you need! Good luck man. Also you'll have to use a .140" over or bigger flathead piston, can go up to .194" over if you wanted.Also for the money you would be better off building a Briggs 305 or 342 unless your dead set on an Animal. Wish thats what I had done when I built my Animal. 305's has way more power and torque and just as reliable. You can do all the same stuff to the 305 and be way more awsome.
 

Warning27

New member
If you want a really good animal or a 305 that will not disappoint you call Bill Westerfeld . We have been running these for 5 years now and if you want to win , He is the man for the job.

The most important thing to remember about these open animal engines . And this is not open for debate it is a FACT.
REPLACE THE ROD EVERY 10 RACES And i am talking about the ARC BILLIT ROD you will see a hair line crack under the wrist pin journal.

SCOTT W.
 

PD Power

New member
To build a fine Animal based firebreathing engine, always start out with the JR Motorsports billet block, which includes the billet crankcase cover.
Included in the price is an optional 5/8 extended deck. Also 3.125 bore at no extra charge, and you can put any stroker you want, in it.

This engine can be run with an Animal, or Intek, or WF head......does not require a special billet head. The billet head, for sure, is a nice piece
but for budget sake, it can be added later....no problem.

An engine done this way, is fully capable of winning UAS races. Overall kart weight should be held down, to the degree possible.
IF you are a 240 lb driver, then go with the big block.
Hope this advise helps somebody!! ......Paul Doss (PD Power
 
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