Delta 7.4 refurb & retube

[beamishken]

Thanks guys seems fairly unanimous that black is the best option. (due to grey being out of stock of course��).

[Fenlander]

I would have said grey until seeing your images of the material laying on the tubes. It had to be black. Very much looking forward to following the refurb.

[fastasfox]

Grey for the front two thirds and black the rear third.
There was a time when black RIB's were fashionable but most builders seem to be moving away now. I'm with you on the red though...it doesn't look right.

[beamishken]

Originally Posted by Fenlander

I would have said grey until seeing your images of the material laying on the tubes. It had to be black. Very much looking forward to following the refurb.

Thank you I'lltry to keep it interesting I'd made my mind up it was to be red & was a bit disappointed to see the material next to the boat but I think black is the logical choice

Originally Posted by fastasfox

Grey for the front two thirds and black the rear third.
There was a time when black RIB's were fashionable but most builders seem to be moving away now. I'm with you on the red though...it doesn't look right.

That's not a bad suggestion but Dave has done me a cracking deal so need to keep the tube construction simple. Would definitely be unique though

[willk]

Originally Posted by fastasfox

Grey for the front two thirds and black the rear third.
There was a time when black RIB's were fashionable but most builders seem to be moving away now.

Perhaps, but he's not retubing a Highfieldesque cookie cutter RIB, it's a bright red vintage Delta. Black was on point then and now. And tomorrow...

[kevinsc]

I think the delta should be red or black tubes as they look awesome in those colours.

[beamishken]

Originally Posted by kevinsc

I think the delta should be red or black tubes as they look awesome in those colours.

I've told Dave to do the tubes in black which seems the best option given the available red is such a poor match

Next step while the boats at NWR&I is dig the engine out of the graveyard & get it into the workshop for stripdown & rebuild. Its been lying there about 8 years & I know nothing of its history so its a total shot in the dark. I did have it almost started but wouldnt quite fire into life, never did much diagnosis, fingers crossed its just low on compression

[kevinsc]

His delta will look smart, looking forward to the rest of the build. Hopefully will be able go out on a cruise with mine is finished.
Kevin

[fastasfox]

Originally Posted by willk

Perhaps, but he's not retubing a Highfieldesque cookie cutter RIB, it's a bright red vintage Delta. Black was on point then and now. And tomorrow...

Went to BoatLife show a few weeks back and many builders ( not sure what you mean with the term cookie cutter though wilk.) have started to move away from black....I personally like the black....but it does look like a Rib the SAS would use.

[willk]

Originally Posted by fastasfox

( not sure what you mean with the term cookie cutter though wilk.)

I meant that they will all look similar, like they were cut from a cooker cutter?

Originally Posted by fastasfox

....but it does look like a Rib the SAS would use.

Yes

Perhaps I wasn't clear, I MEANT that a vintage craft looks best when the vibe of the past era is still evident in the new work done - appropriate materials, colours, upgrades, etc. A Delta will definitely benefit from that treatment.

[beamishken]

Got the engine up on the stand & stripped but Oh dear not what I was hoping for when the head came off

[Steve509926]

Originally Posted by beamishken

Got the engine up on the stand & stripped but Oh dear not what I was hoping for when the head came off

That sure don't look pretty!

Is it salvageable? Bored out, new liners, new pistons, rings, shells etc. Or is it, cost prohibitive?

[beamishken]

Originally Posted by Steve509926

That sure don't look pretty!

Is it salvageable? Bored out, new liners, new pistons, rings, shells etc. Or is it, cost prohibitive?

Fortunately all is not lost, I always had it in mind this engine might need a replacement block & fortunately I have a couple lying around from long deceased yamaha 420's. The engine originally had a lump of liquid metal plugging a hole in the block behind the water pump where they commonly rust through. Sometimes it just rots into the crankcase & a welded repair will suffice but occasionally they rot higher up into an oil gallery then I wouldnt trust a welded repair I was hoping for a simple plug weld job . I initially thought the engine had been removed because of the oil leak where the liquid metal wasn't stuck properly but alas no it had more serious issues.
Reboreing these is cost prohibitive as a set of pistons is £3k+ & I wouldnt do just one oversize bore, some do but I wouldn't. The cheapest way to go when only one bore is damaged like this is have the block bored & a liner fitted & bored to standard size but given its now difficult to find good engineering facilities you can trust with that kind of job & the hole in the block, the best option is another standard block.
Big ends, mains rings valves and springs head gasket etc are all toyota so not particularly expensive . Only internals that are yanmar are the pistons which are yanmar only. I only need one or maybe two which I have spares of anyway

[Steve509926]

Always handy to have suitable engine blocks lying around

Looking forward to reading/seeing how you progress.

[kevinsc]

Hi Beamishken
How is your build get on
Cheers Kevin

[beamishken]

Originally Posted by kevinsc

Hi Beamishken
How is your build get on
Cheers Kevin

Not been much progress lately with this, the boat is still with Dave Cowal & the engine build has grown arms & legs
After deciding to swap the block out due to a hole rotted throug it & a damaged bore from a melted piston I set too cleaning up another block, first one got it all cleand up & honed then noticed pitting in the block between cylinders, so discarded that one & moved onto block no 2 cleaned it honed it then started looking at the size grade marks on the block for the bearings only to discover this earlier Yamaha block whilst exactly the same the journal size code it stamped differently & each bearing would need to be individually checked with plastiguage to select the bearings. There are 7 grades of standard main shells & 3 grades of standard big ends which you select from the chart using the numbers stamped in the block & con rods against the numbers stamped on the crank.
Found another good block which was a yanmar block & turns out to be the best of the 3
Lifted the crank out of the donar block only to find debris from the piston had gone through the centre main bearing leaving debris wiped onto the bearing surface. Took it to my machining guy for a check & polish only to find its 5thou out of true when mounted on the crank grinder. Didn't want to use a ground crank but fortunately I had another crank which checked out okay & polished up nicely.
Priced up the required bearings rings valves and springs etc from toyota who are usually half the cost of yanmar stuff to find the prices are now through the roof. Ended up ordering the stuff I needed from Amayama who I've bought a fair bit of stuff from for my landcruiser but it has to be shipped from Dubai or Japan which means a bit of a wait but the stuff I ordered from amayama which is all genuine toyota stuff cost me £500 would have been £2000 from toyota and probably nearer 4k from yanmar, talk about rip off Britain!
Once the bearings arrive I can drop the crank in & plastiguage the journals to check the clearance, hopefully I dont need to order a second set of bearings to achieve the required bearing clearance.

[kevinsc]

Sounds like you've got your hands full with the engine
Kevin

[beamishken]

Originally Posted by kevinsc

Sounds like you've got your hands full with the engine
Kevin

Yeh its turned into a bit of a mission, annoyingly I also have a 285 Yamaha which is the same toyota block & would probably have taken far less to build but I realy wanted the 6lp as I already have 2 in the hard boat. & Yamaha rings are about £1200 per set and the Toyota rings dont fit the yams.

Asside from the rot hole in the block I thought this yanmar was a relatively easy refresh but its fighting me all the way just now.

[Easedalenovice]

I hope your engine rebuild is going well. Rather a big job. I managed to fix my Yamaha and the boat is on the water.

When do you think this Delta will be up and on the plane

[Iron Dials]

I think the moderators should be advised the Easdalenovices’s account has been hacked.
The “real” poster recently stated- “I have very little interest in your Delta thread and the musing's of a Mechanic.”

Maybe he could just get his own section…..