Open Animal build help

Charger128

New member
Looking to build an open animal. Any help would be greatly appreciated. Looking to make some power but not go super crazy with machine work being as I don’t have the tools to do machine work.
 
Mod 1 Camshaft
Cut 1982 Series Piston with ARC 6248 Rod
Dual Springs
304 Series Tillotson

Nice little animal that'll turn 9000 rpm and not break the bank.

Not questioning your recommendations, but I have always wondered what the stock crank is good for and how long. Can they really hold up at 8.5-9K no problem? Would this very build benefit from ratio rockers being relatively low lift to begin with? I have been looking at buying a used WKA animal (they are stupid cheap, nothing to lose) and throwing some drop in parts. Just never knew how much I can get away with before having to go to the FH stroker crank and really dropping money on the head/valve train.
 
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alvin l nunley

Premium User
Making a horse power without machine work is difficult.
"Compression is the Holy Grail"
A thinner head gasket will help that.
Alcohol is about 10% faster than gasoline. You need bigger jets in the carburetor. More compression will Boost that percentage number.

A cam with More lift and duration is always a help. Ask around for recommendations.

The exhaust gas temperature gauge (EGT) is my favorite for tuning. In my opinion, the CHT is of little use In comparison to the EGT. Learning how to use it is a little more complicated.

Learn how to use the compression gauge, the air density gauge.

50 years of karting experience has taught me these things.
 

Jimbo

You can fool some of the people some of the time
Depends what you consider better.
The slide carbs are (WF, Mikuni etc) are very simple and very easy to maintain,
If you compare them with any other carb of equal size they can make just as much HP as a diaphragm carb. I'm not picking on the WF carb. It works very well but be aware that a 26 mm WF carb is 26 mm where it bolts to the intake manifold but in the oblong venturi area it is considerably smaller.
A 24 or 28 mm Mikuni flat slide will flow way more air than a 26 mm WF carb because it doesn't have the restriction or venturi area that many other carbs have,
 

Repoman

Member
Listen to jimbo he has a dome piston for stock bore and buy one of his heads keep stock crank and put a rod and cam i run stock cranks and they hold up fine i even run the stock flywheel on one of the engines jimbo is the man for animals
 
Depends what you consider better.
The slide carbs are (WF, Mikuni etc) are very simple and very easy to maintain,
If you compare them with any other carb of equal size they can make just as much HP as a diaphragm carb. I'm not picking on the WF carb. It works very well but be aware that a 26 mm WF carb is 26 mm where it bolts to the intake manifold but in the oblong venturi area it is considerably smaller.
A 24 or 28 mm Mikuni flat slide will flow way more air than a 26 mm WF carb because it doesn't have the restriction or venturi area that many other carbs have,
Appreciate the honesty. We have just been on clones/predators and starting to build some opens that no longer have to run stock appearing carbs, was thinking about robbing a WF carb from my sons junior program to use on one of them
 

Charger128

New member
Anyways. Does anyone have any info or combos they have run that work well. I don’t need a crazy stupid HP motor where I need extended decks and so forth. Track is on the smaller side.
 
If money is no object , put new flathead crank or ARC's Billet crank, rod and wiseco piston to match, Get world formula head that has been ported or one of the billet heads with big valves, A 380 Tillotson., go with .dyno 310 cam with or without ratio rockers , it will fly without them).And the ARC flywheel just for the flathead crank in the animal. PLV naturally. And use the composite metal ,or copper head gasket, the breather bypass . You will need to get the crank gear for the animal cam. 27 tooth. Still no machine work on your part.
Alcohol!
All of the machine work is in the head and will already be done. I have one of Jimbo's heads that the oil galley was filled. ported big valves. It is just a bolt together engine. Except you will have to drill one hole in the valve cover for the bypass. Or you can buy them already drilled from a couple of builders.
 
I have a couple of the heat treated cranks left but I still went with billet ARC. It is really nice. Engine is only as strong as the weakest part. Cranks are one of the main parts. I know some that are running used flathead cranks but the don't turn them as high as I do. Makes a difference.
9,000 is easy with the billet crank and no worries. that build is really strong! fast and smooth.
 

steve baker

Moderator
3 most important ................camshaft, compression and ignition timing. As cylinder pressure increases the ignition timing becomes very important, get that right!

Steve
 

mike97760

Premium User
I've got a couple of Animals, one is a pretty good limited modified motor with a 304 Tilly, the other has a bit bigger valves, uses a 28mm Mikuni, has adjustable flywheel and is just a bit stronger. Both have stock rockers. I bought both and haven't personally worked on either. From my limited experience with them my concern is that on small tracks neither is real strong when accelerating from off throttle but exceptionally strong once rpms pick up. So small tracks are their weakness. I don't mean to hijack your thread, just interested in the responses you get.
 
I've got a couple of Animals, one is a pretty good limited modified motor with a 304 Tilly, the other has a bit bigger valves, uses a 28mm Mikuni, has adjustable flywheel and is just a bit stronger. Both have stock rockers. I bought both and haven't personally worked on either. From my limited experience with them my concern is that on small tracks neither is real strong when accelerating from off throttle but exceptionally strong once rpms pick up. So small tracks are their weakness. I don't mean to hijack your thread, just interested in the responses you get.
Sounds like you just need to throw some more gear at it, when in doubt rap her out. Seeing as you didn't build them they may not have the right cam for small track or not enough compression, too much carb or plethora of the above
 
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