Perkins 4.154 Crank Pulley removal

[sea_hunter]

Originally Posted by SloopJonB

Indeed I don't (it IS a brute though). I've never seen a serpentine system without a powerful spring loaded tensioner - the one on my wife's minivan requires a breaker bar to unload the tension. How is tension maintained on the belt on the system you describe?

Yes automotive serpentine belts require a loaded tensioner, the ones used on marine engines employing large case alternators do not. The belt goes around ALL the drive pulleys, but underneath the idler pulley. The tension is loaded with the alternator adjusting arm. The main reason it's done this way is that marine diesel engines don't operate at variable and higher engine RPMs (therefore no backlash that causes the belt to "jump") like automotive engines. Hope that helps.

[SloopJonB]

Originally Posted by sea_hunter

Yes automotive serpentine belts require a loaded tensioner, the ones used on marine engines employing large case alternators do not. The belt goes around ALL the drive pulleys, but underneath the idler pulley. The tension is loaded with the alternator adjusting arm. The main reason it's done this way is that marine diesel engines don't operate at variable and higher engine RPMs (therefore no backlash that causes the belt to "jump") like automotive engines. Hope that helps.

Thanks - good to know.

[TYLERWCOM]

I have been stuck in this project because I decided to proactively replace the water pump since I had the front of the engine mostly apart.

Perkins had TWO versions of the 4.154. One they made and one that Mazda made under license. My engine number is A07_J13352U. The J means Japan and that means Mazda.

A good engine was made by Mazda I was told. But it is NOT the usual North American version with North American Accessories. The manual posted earlier in this link has the INCORRECT water pump part number listed as U5NW0053 (hand written) corrected to U5MW0053 (still not correct for a Japan engine). The good part number is 136315100A (Mazda) I have seen this NA version manual, with the hand written pump number, posted all over the web

I removed the entire water pump casting and took my manuals (also North American) to the Perkins dealer. One of them spotted the J in the engine number and said, "you have the Mazda version!"

A day later I had the perfect drop in pump unit !!
(learned more about Perkins than I wanted to, but now I know I have the Japanese version.)

Now on the the alternator project...

[sea_hunter]

Yeah, that's an oddball for sure. I know the license built Perkins 4.154, it was imported into Canada in the Mazda B trucks and the Ford Ranger in the mid 80's. It's pretty much the same engine but with Mazda specific externals. What heat exchanger does it use? Just for future reference, ALL the Perkins part number beginning with USN or USM, are invalid. Since Cat bought Perkins, all part numbers have numerical references.

[dacap06]

I'm sorry to have misled you with the manuals. It wasn't intentional. Looks like we have ALL learned something!