Caterpillar Sixty Backfiring

Caterpillar Sixty owned by Virgil White running at the Antique Gas and Steam Engine Museum September 21 2008. The Sixty was built with a 6 1/2" bore and a 8 1/2" stroke. The previous owner of this Sixty plugged up the block and overheated the engine. It cracked three heads and cooked the rings. When Virgil got the tractor in 1978, he managed to find a brand-new set of aftermarket cylinders, heads, and pistons at a longtime Caterpillar repair shop in Los Angeles. The cylinders are 1/4" oversize and are bored 0.080" on top of that. The pistons are domed high-compression pistons, with a popup of 3/4". We estimate the engine makes 20-25 horsepower above the stock rating of 77. This tractor hadn't run for about 5 years. I tried to bar-start the engine over earlier the same day and it would not even fire once unless about a shotglass worth of gasoline was poured into the priming cups on the manifold, and when it did fire, it wouldn't carry over to the next compression stroke. It turned out that the magneto timing had slipped by 30-35 degrees. In the first part of the video it is running 30 degrees retarded. The vacuum leak doesn't help any. Note the two fiery backfires around 2:10-2:30.

Category:

Science & Technology

Tags:

• caterpillar
• cat
• holt
• best
• sixty
• 60
• tractor
• bulldozer
• tracklayer
• crawler
• big
• bore
• backfire
• cummins
• detroit
• international

[hardcockish]

that thing thas a 3/4 cam

[caterpillarnut]

@hardcockish

Yup. It'll run low 12s in the quarter.

[ravecord]

what an awesome machine

[darkpanda008]

sounds like the injectors are shot to me.

[tpvalley]

@hardcockish

where does the 3/4 come from in relation to hig lift cams?

I have always used duration and lift.

[SchuyTV]

@caterpillarnut 12 minutes or 12 hours? lol

[theonly9]

@caterpillarnut 12 minutes right?



[trashratt]

@thejoebinator I was thinking the exact same thing!

[crocodile2006]

@caterpillarnut

12 Minutes?

[thejoebinator]

did somebody lose a socket during maintenance?

[ToledoDom]

try repairing the intake leaks and adjus tthe timing on the mag.

[TheSoloAsylum]

its about to run backwards