Animal motor ?

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PitchiefON18c

New member
Was wondering how many races on a limited mod motor animal on alky how many races can i get before i should have it gone threw and rebuilt wuts the going price on eastcoast im in cali was just wondering its still strong motor im getting about 8,000 rpm8100 top speed 48 1/8 mile oval clay thxfor yourinfo
 
Because of all the variables putting an exact number on something like this is impossible.
To be safe I'd replace the rod bearings after every 5 race events. You can probably double that but for less than $25.00 it's cheap insurance.
Keep the dirt out, used Briggs Racing oil, change it often, pickle the engine properly and put at TDC after each race.
 
PitchiefON18c said:
Was wondering how many races on a limited mod motor animal on alky how many races can i get before i should have it gone threw and rebuilt wuts the going price on eastcoast im in cali was just wondering its still strong motor im getting about 8,000 rpm8100 top speed 48 1/8 mile oval clay thxfor yourinfo
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Some where between 8 and 20 races. A lot depends on who and how it was built. Running at 8000 rpm ( kinda low for a Lim Mod ) I would think 8 to 10 races would be no problem. As Jimbo said, keep clean oil in it and change oil often.
Using the proper cylinder wall to piston clearance, good connecting rod, billet crank gear and ring package would be important for these engines. On a side not be careful with the aftermarket piston pins, some of them are too thin and will break! Years ago when WKA had the gold cup series and the Lim Mod was popular we ran 8800 to 9200 RPM on sprint tracks, at 8000 rpm as i said would extend life significantly. Engine failure rates go up exponentially as rpm increases above 8500 rpm.
A little in site into these engines, one of the bottom end problems is keeping enough oil in the bottom end crankcase area. At these elevated RPM levels too much oil is pumped up top and this will starve the rod / crank for oil.

Steve
 
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How does one know if the cylinder needs to be bored and a new oversized piston and rings installed?
How does one know if the crank is worn and needs to be replaced.
Does the rebuild require new valve springs?
Has the piston pop up or cylinder head machining been maximized?
Does it have the right cam installed and if it does has it been degreed in to take advantage of the rules?
Do the rocker arms provide the maximum lift allowed
Is the carb doing it's job?
Does the shop dyno test and tune each engine it does?
If your business model is based on price only then fine. Charge X amount and do X amount of things.
If you business model is quote a price to lure people to your shop and once you get their engine you make the phone call and tell them they need to spend another X amount of dollars. Your reputation will reflect that.
If you do your research you can find people that are honest, trustworthy and won't rip you off.
If you don't trust the person working on your engine to treat you right then go someplace else.

Steve is 100% correct about these engines pumping excessive oil into the valve cover and there not being enough oil in the crankcase to survive.
Briggs developed the Breather Bypass many years ago to help prevent this.

Merry Christmas to all ;)


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