Perkins 6354HT - Steam from exhaust investigation

[Ghodula]

Hi

Checked for head gasket but I've got no water in the oil or visa versa. Also did a sniffer test and no combustion gas in the coolant, so far so good.
Starts and runs happy as a clam but gets steamy under load.

I think the raw water exhaust manifold may have rotted out.
The below is my engine with the exhaust elbow disconnected from the turbo/exhaust housing. There's a close up below showing that this is full of raw water. Main question: Is this normal?
I would have thought 'Hose A', which carries raw water from the exhaust wet manifold jacket, should be the only thing carrying water until it dumps it back into the exhaust elbow. It is shown with a white extension hose on it in this photo, as I wanted to see what came out of it. Usually it connects near where the 'Exhaust elbow' arrow points.





This is what came out of 'Hose A'. Looks like alot of exhaust soot in the raw water coming out the wet manifold

Any advice greatly appreciated!

 

[burgundyben]

I know the T6 intimately having run them for 15years, less so the HT.

Tricky without looking at the boat, but I think you are right, your manifold has failed.

Unless water is running the wrong way from the water injection point , but thats a design thing and you'd have known pretty soon.

There's a complete HT6 on ebay at the moment

 

[Restoration man]

Hi if your stuck for a manifold I’ve got a spare brand new old stock genuine perkins t6 one never fitted ,better than the reproduction I want £1000 Ono very rare

 

[penfold]

I'd be equally concerned about the turbo being fritzed from all the salt; if it's not the elbow the manifold(which are unobtanium for the HT I think, you would need to get one custom fabricated) is knackered.

 

[burgundyben]

I'd be equally concerned about the turbo being fritzed from all the salt; if it's not the elbow the manifold(which are unobtanium for the HT I think, you would need to get one custom fabricated) is knackered.

I didn't like to say it, but I suspect that motor has come to the end of the road. Finding a replacement that fits in the hole might be tricky with a capital T.

That elbow manifold you refer to has been remade, cant recall exactly but I think either Broom Owners Club or Lancing Marine. Lots of HT6 in Brooms and so their club has expertise snd support.

 

[Ghodula]

Thanks for all the replies.

Very fortunately the manifold is in two pieces with the pod under the turbo being accessible. The main mainfold is under the engine on the HT and while maybe not totally impossible to get at, would have been likely been an engine out job.

I took the hose that connects the two pieces and was relieved to see exhaust gas coming out the bit I could get to!

Always think it's nice to follow these things up, so here's some pics of the findings.
Will hopefully be able to get it welded up.


I think I caught the turbo in time, still spins freely with no play. It definately wasn't having a good time though!


Feeling very happy, as it looks like we may be able to do some boating this summer now after all
Boat is a Brooms Ocean 37 in case you were wondering.

P.S. Thank you for the offer of the new manifold and I don't suppose anyone knows where to go for a new gasket set? If not I guess I could make them out of sheet material but what sort of material should I use?

 

[burgundyben]

Fingers crossed.

There used to be a chap in the Broom Owners Club called David Harrison. He knows the HT6 very well and I think was instrumental in getting that part remade.

 

[Ghodula]

The elbow I had in my first photos was indeed new as the old one had rotted out.
Might make more sense now as it was getting boiling hot saltwater blown through it.
Not sure how long this problem has been manifesting as when I first took the piece of exhaust manifold off with the damage, it was more of a crack, it only turned in to a hole when I cleaned it and lumps of it fell away.
5 years ago when I bought her, I noticed the exhaust out that side (twin engine) seemed 'smokier' This may have been cracked and leaking slightly for years until it let go enough to be truly noticable.

On a side note I was supprised to find this end part of the manifold is made from cast aluminium. I would have thought mixing cast iron and aluminum in combination with salt water and hot gas is a huge no no corrosion wise. Then again here we are! but apart from the localised hole, everything seems to be in good condition. Heyho.

Thanks again for the contact information burgundyben

 

[burgundyben]

If you look on your water pump on the front of the block you might see a spare port with a bung in it, you can route coolant from there into the front of the exhaust manifold, then rout out of the vacknof the manifold inyo a hose tail fitted in the inspection hatch onthe back of the head, thus bringing the exhaust manifold into the coolant loop.

 

[Ghodula]

Is this a way to cool the 'pod' bit of the maniflold that the turbo sits on, with the closed loop engine cooling instead of raw?

If so, I already have an immersion heater running off that loop (If i've understood correctly).

If i've got all that right, then i could see how cooling the pod bit with closed loop coolant would reduce corrosion on it, although if it did let go, it would bugger up the engine rather than 'just' the turbo?
It's a given that if the turbo breaks up and throws bits of its self into the engine then it's a moot point !