VP heat exchanger end cap bolts

[raptorheli2]

Hi all,

Need to order new bolts for the end caps, not sure what the exchanger is made of though to pick up bolts locally. I assume it is cast bronze or something similar (D3 190)

The bolts are slightly yellow and magnetic.

Would 316 be okay with anti seize?

 

[starfire]

Just passivated steel.

 

[madabouttheboat]

Hi all,

Need to order new bolts for the end caps, not sure what the exchanger is made of though to pick up bolts locally. I assume it is cast bronze or something similar (D3 190)

The bolts are slightly yellow and magnetic.

Would 316 be okay with anti seize?

Why risk it. Just buy original replacements.

 

[raptorheli2]

2 reasons mainly.

1. I needed them quickly (which I've now got)
2. No one wants to pay volvo penta tax for a bolt in a packet.

6x bolts and 3x O rings from volvo to fix the exchanger would have been £ £110.

Local hydraulic place had the seals and same bolts £23 total

Ironic as the reason I'm fixing it is volvo kindly stripped the bolt on it when it was made and painted over it.

 

[madabouttheboat]

2 reasons mainly.

1. I needed them quickly (which I've now got)
2. No one wants to pay volvo penta tax for a bolt in a packet.

6x bolts and 3x O rings from volvo to fix the exchanger would have been £ £110.

Local hydraulic place had the seals and same bolts £23 total

Ironic as the reason I'm fixing it is volvo kindly stripped the bolt on it when it was made and painted over it.

Although £40 for 6 screws does seem a tad excessive, in the grand scheme of things it is a drop in the ocean to ensure you get the right material. Galvanic corrosion on your heat exchanger could end up costing over £2.5K.

 

[vyv_cox]

Although £40 for 6 screws does seem a tad excessive, in the grand scheme of things it is a drop in the ocean to ensure you get the right material. Galvanic corrosion on your heat exchanger could end up costing over £2.5K.

The bolts hold the end cap on. They should not come into contact with any liquid.

 

[raptorheli2]

Correct, should be zero water

 

[madabouttheboat]

Correct, should be zero water

The bolts hold the end cap on. They should not come into contact with any liquid.

Should, being the important word. A slight weep on the end cap is all that it would take. Or a leak anywhere near on the engine, or just one of those salty damp engine bays that boats often have.

 

[raptorheli2]

Should, being the important word. A slight weep on the end cap is all that it would take. Or a leak anywhere near on the engine, or just one of those salty damp engine bays that boats often have.

I'll worry about it in 10 years then

 

[vyv_cox]

Should, being the important word. A slight weep on the end cap is all that it would take. Or a leak anywhere near on the engine, or just one of those salty damp engine bays that boats often have.

There must be billions of similar arrangements around the world - not just in yacht engines but in every engineering construction you can think of. How many experience disastrous failures? Very, very few.

 

[madabouttheboat]

There must be billions of similar arrangements around the world - not just in yacht engines but in every engineering construction you can think of. How many experience disastrous failures? Very, very few.

All im saying, having seen how quickly these housings, that cost thousands, can corrode, why take the risk using potemtially bolts of the wrong material to save maybe £30.

 

[raptorheli2]

Dude, it's a bolt that was replaced with a suitable one, not a b&q special.

This might come as a surprise, volvo do not make bolts, paints, antifouls, oils, filters, anti freeze, timing belts, pistons, bearings etc etc.

 

[rogerthebodger]

Corrosion only takes place when you have 2 dissimilar metals electricity connected together in an electrolyte (sea
water)

As there should be no electrolyte in the cap screw threads there should be no corrosion.

I did have an aluminum heat exchanger corrode due to a failure of the end cap seal

Check for any seawater leakage

I had my heat exchanger welded up and hand fled back to the required shape

 

[PetiteFleur]

Slightly off topic, my early Beta 25hp has a heat exchanger with a single central bolt for the end caps. One just snapped on first start after launch - fortunately I had the hatch open and immediately stopped the engine. Beta recommend these bolts are replaced every 10 years. Mine were 12 yrs old so replaced both - some bronze I believe.

 

[rogerthebodger]

Slightly off topic, my early Beta 25hp has a heat exchanger with a single central bolt for the end caps. One just snapped on first start after launch - fortunately I had the hatch open and immediately stopped the engine. Beta recommend these bolts are replaced every 10 years. Mine were 12 yrs old so replaced both - some bronze I believe.

The same thing happened to mine some time ago again causing corrosion due to seawater attacking the aluminum

 

[raptorheli2]

Unfortunately we haven't found much yet we can put in contact with salt and not corrode to some extent.

My boat is dry stacked so does help.