Mercruiser 260 heat exchanger and cooling hoses

[bmoresearay]

I have a 1982 mercruiser 260 with a closed loop cooling system and am unable to identify the cooling hoses for replacement. It is equipped with a 74643 mercruiser heat exchanger which doesn't show up as an option for this motor on any of the parts diagrams i find. Everything is working fine although i would like to replace the hoses from the seawater pump to the cooler and onto the heat exchanger, as well as the hose from the circulating pump to the heat exchanger. Any help is greatly appreciated.

 

[greno]

This is what you got and these are the sizes you're going to need. You may have difficulty finding molded hoses for these old models. What I've done in the past is use straight hose and insert 45's or 90's to make a neater install.

 

[Scott Danforth]

dont frankenstein hoses....that is beyond bad practice

hoses still available from mercruiser (use your serial number)

also hoses can be identified easily https://www.gates.com/resources/resources-library/catalogs/molded-coolant-hose-identification-guide

 

[bmoresearay]

I was able to replace quite a few with straight runs. No kinks and kept it clean. The circulating pump hose however takes that sharp 180 degree bend and enters the heat exchanger in a very compact space. That is the one I am looking to have a spare of as it is 35 years old. My thought is to remove them at the end of the season, measure and photograph them and hopefully get some help. The kit and heat exchanger I have match up to a 305 from that era and not my 350. Neither of the diagrams show this hose and my original though was maybe they use the raw water hose which connected from the circulating pump to the thermostat housing. I will keep digging and thank you all for the help.

 

[greno]

My heat exchanger is similar to yours and what I used to go from the water pump on my small block to the underside of the heat exchanger was actually a big block hose that I cut a bit off at the top to fit. It actually fit better than the hose that was called for on the small block.
search: mercruiser 32-861183

 

[bmoresearay]

That hose looks very promising, I had looked at the full kits for big blocks and the front view of one of them looked exactly like mine. I wasn't sure if the sizes would match but certainly worth a shot. Much appreciated and I will order one of those to start.

 

[Scott Danforth]

the 305 and 350 used the same heat exchanger.

 

[bmoresearay]

I was able to track down some info, thank you for the help. My particular model is equipped with closed cooling and the power steering pump and cooler. Part #77640A1 includes the hoses from seawater pump to steering cooler and onto the bottom of the heat exchanger. The original circulating hose is used (per mercruiser manual) and cut to fit. This leaves me with only one odd ball hose on the port side from t-stat housing to manifold to make up which shouldn't be a problem. Thank you for the info and help.