Intercooler O-rings

[Erin]

Just wondering if anyone knows which is the best material for intercooler and heat exchanger O-rings on a marine engine? O-rings seem to come in various flavours, including Nitrile, Viton, Silicone, etc with varying hardnesses and temperature limits.

[bedajim]

Originally Posted by Erin

Just wondering if anyone knows which is the best material for intercooler and heat exchanger O-rings on a marine engine? O-rings seem to come in various flavours, including Nitrile, Viton, Silicone, etc with varying hardnesses and temperature limits.

Any idea on the temperature and what is coming into contact with it, water, oil etc

[captnjack]

Are they not available from the manufacturer in the correct hardness, material and size?

[Erin]

Originally Posted by bedajim

Any idea on the temperature and what is coming into contact with it, water, oil etc

Standard modern marine diesel, so charge air to raw water in one and coolant to raw water in the other. No idea what temp the charge air gets up to, but coolant will obviously be sub 100 deg (if it's above that the o-rings will be the least of my worries )

Originally Posted by captnjack

Are they not available from the manufacturer in the correct hardness, material and size?

Yep, but at a price and with a current delay due to stock levels. £19 per ring seemed a bit steep to me .

[captnjack]

Originally Posted by Erin

Standard modern marine diesel, so charge air to raw water in one and coolant to raw water in the other. No idea what temp the charge air gets up to, but coolant will obviously be sub 100 deg (if it's above that the o-rings will be the least of my worries )


Yep, but at a price and with a current delay due to stock levels. £19 per ring seemed a bit steep to me .

Wow that is steep! Do you know anything about the current ones? Do you at least have them for size?

I would guess they are a high temperature rated silicon in 90 durometer. Viton or Buna nitrile may work too. EDPM is probably not heat tolerant enough. (they are all good to >100C just some materials breakdown sooner)

[Erin]

Fortunately I have the sizes from the manufacturers parts list. One appears to be metric (4 x 135mm) and the other imperial based (3.53 x 118mm) . Clearly a case of different manufacturers for each of the units.

[Leapy]

Originally Posted by Erin

Yep, but at a price and with a current delay due to stock levels. £19 per ring seemed a bit steep to me .

In automotive, they're normally silicon based to withstand temperature and pressure. £19 is cheap if it buys reliability and durability

[Erin]

Originally Posted by Leapy

£19 is cheap if it buys reliability and durability

Less pallatable when you need 8 of them though. Aftermarket seem to run at £2 or £3 a ring. I could afford to keep some spares at that price.

[Leapy]

Originally Posted by Erin

I could afford to keep some spares at that price.

Yep...