The following warnings occurred:
Warning [2] Undefined variable $search_thread - Line: 60 - File: showthread.php(1617) : eval()'d code PHP 8.1.31 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/showthread.php(1617) : eval()'d code 60 errorHandler->error_callback
/showthread.php 1617 eval




Thread Rating:
  • 1 Vote(s) - 5 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Original ulster engine rebuild
#1
Well after an unsuccessful drive at guildtown. It's time to tackle the supersports engine.

Yes it's an original ulster engine, and I'm sure many would be afraid to use it. I've always had the same view there. If it's not being used. WHO is it being saved for.

anyway let's start with the problem, late last year I started to get the problem that the engine wouldn't start as quickly as it had, or even without choke. I put the car away in November. And in march a customer asked if I could start it for him. When I tried it refused totally with a no start. It sputtered a few times. Then nothing at all.

I checked the carb, fuel was going through fine. I checked the distrib. The rotor needed cleaning. And the engine started.but ran poorly.

So thinking it was an electrical problem, I started changing plugs, no change. Cap and leads, no change, condenser, no change. Coil, no change. I didnt change the contacts, but they were cleaned and adjusted.

Symptoms from here are, the engine starts with no throttle. But when revved it is rough, and the revs are not responsive, slow to build, then everything.

I gave it a road run before going to scotland, and it was the same on the road. Lumpy to get going but when it did it ran at 70mph as if it was a new car. So I thought I'd get away with the scotland weekend.

Sadly no, took the car into Perth friday. Alot of traffic. And everything just got worse.

I decided not to do the run Saturday, as I didnt want to risk a bigger bill. The only light relief was we got a trophy for car needing the most work Big Grin 

I've always felt the carb is far to rich, I've had the block off in the past to fix leaks, and the play in the bores was HUGE, and the distrib had plenty of slop in it.

So when I got back this week, the decision was to strip everything out and start from scratch.

Let's see what's working, and what's not.

So tuesday the 30 MOV carb came off, and was sent to the countries expert on these carbs. All being well a couple of weeks time it will come back ready to go.

I also phoned to made sure I could get the block in for a rebore, the answer. Drop it off saterday morning. Should be 1 1/2 to 2 weeks.

So here's the strip down, as of today.

   

Plenty of oil on the starter, although I have NO clutch slip?

   

Losing plenty of oil under the car, on sump. And dripping down chassis.

Although I should say, a new leak started before scotland.

Turned out, oil was being forced up out of the rev counter cable. Which is in the nosecone.

   

Engine out.

   

   

Alot of oil around the engine bay.

   

This one surprised me.

The exhaust is a 3 into 1. So centre stud is cut off.

The exhaust is blowing between 2 and 3 exhaust port.

   

This is were it starts to get fun.

Removed the head.

The seal on the gasket is stunningly good.

But check the NEW spark plugs, 3 are parcially sooted. And 1 is fully sooted. They have only been in for 15 miles.

Also check the white patches over the inlet valves, but only in 3 cylinders.

   

   

Dont worry about the head gasket, I'll be putting a new one on Big Grin 

But also check the whitening around the inlet valve.

   

The pistons are old seven workshop ones.

I've tried to show the slop. It's around 30 thou. And should be around 10 thou.

Also after checking the bores. Number 3 cylinder is starting to get two grooves from the gudgeon pin.

This could be part of the progressive problem.

   

I dont know if the pics will show the sideways movement in the pistons.

However, they are standard pistons.

That's as far as I have gotten today.

Tomorrow the block has to come off, to go to the rebores saterday morning.

End of day 1.

   
Reply
#2
Good progress Tony. Looks like you’ve got it all in hand then for a rebore and a rebuild. What’s bottom end like or haven’t you got that far yet? Looks like if you’d of used it much more then you would be looking at some serious damage there so a good call by the looks. Hope she’s back on song soon lovely car that. Keep up the good work and hope it goes smoothly. Like you say pointless saving it nice to see it being used and not just stuck under a bench. Nice to see progress pictures very interesting
Reply
#3
Great to see such a detailed account of the job Tony, very educational. What bore size at present? hopefully there's enough room to get rid of the gudgeon pin lines and the wear.

What causes the white patches?
Reply
#4
thanks joe.
i have to have the block off today, so it can go in tomorrow.

i have some orders to do, but may get onto the bottom end this afternoon. orover the weekend.

hi peter,

the current pistons are standard, but as you can see the bores are baggy.

tony
Reply
#5
Stripped the block out today.

Just as well.

As the picture shows there are scores, but are not from a gudgeon pin.

So it's ready for a rebore.

   

all the paper gaskets kept a good seal.

Which also shows the surfaces are flat.

So I wont need to bring surfaces, just clean everything.

   

On removing the valves.

It's obvious the soot is getting down the guides.

Exhaust valve number 2, opened and closed when the engine was turned. But was tight on removal.

This could explain some of the symptoms, tickover was fine. But Lumpy when revved.

   

   

   

The water jacket had the usual crude build up.

   
Reply
#6
Again cracking work. Nice to see a sports block close up. Like you said I think you managed to catch it in time before it did any major damage. Look forward to seeing further updates as it’s very interesting. Thanks for sharing with us on here
Reply
#7
Any expalnation for the scoring? Have stones got in?
Reply
#8
thanks joe,

bob im not sure about the scoring.

could be dirt from the tank? i have the small filter gauze at the carb. and this has particals on it.

i may consider flushing the tank as well as doing the engine before it all goes back together.

ill do some pics of the filter latter.

the block went in today.

tony
Reply
#9
Great post Tony, I love stuff like this. I’ve only ever seen score marks like that when a ring has broken up...and in years gone by I would have put a set of Cords in and got another 30,000 miles out of it!
Reply
#10
Hi ivor,

There are NO broken rings.

And if it wasnt such a valuable engine, I might have done the same thing to get to the centenary and back.

I have found some of the problem.

I'll put pics on and catch you up.

Tony

I've been stripping the bottom end down.

First the sump.

There is a little grit in the oil, and some small bits something.

   

what is on my finger is the something in the oil.

My first thought was gasket sealant.

But it isn't, the answer is to come.

   

Oil filter is clear.

And the cassings are still nice and clean after its last full build 35 years ago.

   

   

   

I needed to remove the nosecone to see why oil was being forced up the rev counter cable.

Theres plenty of oil everywhere.

   

   

Then I found this.

The seal round the starter dog has broken in 2.

These are the rubbery bits in the sump, and showing on my finger.

And it will be the reason why the nosecone was filling with oil, and being forced up the rev counter cable.

Oil pressure on the gauge was fine, 45lbs cold. And 25lbs hot.

But this may not meen I had the same in the crank.

I've checked the big ends for play.

1, 2, 3, are fine, 4 has a small amount of play.

I'll see how bad it is when I remove the rods.

   
Reply


Forum Jump:


Users browsing this thread: 3 Guest(s)