Scottie on the road

[Mick O'Malley]

Good to know it's turned out to be something reasonably simple and inexpensive .

Good luck with the head refurb.

Apparently these are the gaskets of choice.

[Paul L]

Scottie - Sorry to hear about your engine problems, but at least you now know what the problem is.

Good luck getting back on the road, Paul.

[swifty]

Great to see the problem has been found, regards head gaskets if you have the head skimmed by a motor engineer they will supply you with a new gasket most likely to the correct thickness in relation to the amount they remove to keep the original compression the same, it usually depends on how much material they remove.

[WorldClassAccident]

I was right!*

* without even knowing what I was talking about. :-)

[IanA]

Originally Posted by IanA

and a +1 from me- Dolly's were known for it...

And now seeing that ridiculous inter-bore gap between 1-2 and 3-4, I'm not surprised.

Often happens on over-bored engines but on a production engine- why do that?

[Scottie22]

Just what I thought Ian, its begging for trouble is it not?
In the future, every time I put my foot down, I'll have a mental picture of that stupid little strip!!

I have just come back from the engineering shop, and they are talking about getting the head done for the latter part of next week, so we will see.

[reneanglia]

On my top-fuel dragbike after each run the head was lifted to check it all,i used a gasket made of copper which was glowed an reused again,these gaskets never failed.
Thinking about lasercutting these days it would be easy to make one for your engine.....

[Mick O'Malley]

Originally Posted by Mick O'Malley

There was a real XKSS, D Type and C Type there

A couple of snaps newly printed from my analogue camera

[Scottie22]

Thanks for that Mick, I must have missed the XKSS!
What a bummer, as I took pics of the fabulous D Type.

I did ring you a few times when I was there, but could not get hold of you.

There will be other days.

[deggsy]

glad to hear you found out what the problem is Scottie I'm sure you'll be back on the road soon. the joys of classic motoring

[Alpha]

Originally Posted by IanA

And now seeing that ridiculous inter-bore gap between 1-2 and 3-4, I'm not surprised.

Often happens on over-bored engines but on a production engine- why do that?

Because the 1500 basically IS an overbored engine. It was originally designed an 803 cc four pot for the Standard 8, and then enlarged to 947, 1147, 1296 and finally 1493 cc - the gap between 2 and 3 is determined by the centre bearing of the crankshaft, so to enlarge it, they had to reduce the space between 1-2 and 3-4

As you can see from Scottie's pictures, 1493 cc was the absolute maximum they could get without a major redesign of the basic block...

[oxford1360]

Originally Posted by Alpha

As you can see from Scottie's pictures, 1493 cc was the absolute maximum they could get without a major redesign of the basic block...

I would say that as you can see from Scottie's, 1296cc was the absolute sensible maximum they could get without a major redesign......or a constant supply of head gaskets.......

This is my 1300 +40 thou -

It's the same as Scottie's - pretty narrow walls. To go to 1500 they stroked it from 76mm to 87.5mm whilst preserving the same 73.7mm bore as the 1300. Thus producing an undersquare design............which is one reason why it doesn't rev quite as happily as the 1300.

[Scottie22]

Aaah! The plot thickens, That's one reason why a racing 1300 can rev to 9000 revs quite happily, but the 1500, with only three main bearings..........mmmmmmmm.

[oxford1360]

From Wikipedia -

"An engine is described as undersquare or long-stroke if its cylinders have a smaller bore (width, diameter) than its stroke (length of piston travel) - giving a ratio value of less than 1:1.

At a given engine speed, a longer stroke increases engine friction (since the piston travels a greater distance per stroke) and increases stress on the crankshaft (due to the higher peak piston speed).

The smaller bore also reduces the area available for valves in the cylinder head, requiring them to be smaller or fewer in number. Because these factors favor lower engine speeds, undersquare engines are most often tuned to develop peak torque at relatively low speeds."

[Scottie22]

Hey Ox, you seem to be pretty clued-up, what sort of life-span would we expect from a new head gasket, given the
thin gaps between cylinders 1-2 3-4 ?

[oxford1360]

Hi Scottie,

If you use a good gasket, new head studs and torque it properly.........and you are running "normal" compression......and it never overheats...........I would expect a gasket to last as long as it needs to. i.e. I would expect to have the head off for something else before the gasket ever went.

I don't tend to push road engines too hard but others who do might have other thoughts.

I am quite paranoid about engine temp so on mine I may even put a dash light that illuminates when the fan cuts in.

I added a temp gauge to my Morris Minor. I now know why they didn't bother. Once warmed-up it never moves from 85 degrees in summer or winter. The term over-cooled springs to mind but that suits me just fine.

Look after your water pump, coolant and rad and they will look after you!

[IanA]

Originally Posted by oxford1360

From Wikipedia -

"An engine is described as undersquare or long-stroke if its cylinders have a smaller bore (width, diameter) than its stroke (length of piston travel) - giving a ratio value of less than 1:1..."

Their one advantage (I've found) is in the difficult starting scenario- providing the battery will get one piston past TDC on a compression stroke and it fires... it will start.

I can't say that about the oversquare Ford engines I've owned!!!

[IanA]

Originally Posted by oxford1360

Hi Scottie,

If you use a good gasket, new head studs and torque it properly.........and you are running "normal" compression......and it never overheats............

...and you don't boot it until the temperature gauge needle is off its stop ie the thermostat is open.

I once heard of a Fezza dealer who would demonstrate by starting the car up cold in the showroom and immediately bouncing it off the rev-limiter. Ensuring future servicing revenue perhaps?

[Scottie22]

Well, I got my re-conned head back from the engineers, all re-built, and ready for running on unleaded.

I decided to paint it red to match other stuff on the car, ( red black and silver always looked good on F1 McLarens) and treated it to a new water pump. The old one was fine, but an unknown quantity.

I pushed the boat out, and have bought an alloy rocker cover, as I was too lazy to do up the tatty old one.
It should look a bit more presentable under the bonnet when its all back together.

I have new fuel line and hoses to fit, and must buy some quality hose clips, as I am tired of the crappy old rusty things they seemed to use in those days.

pics:

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[IMG][/IMG]

[Jaguartvr]

Could be an ideal time to upgrade to Evans waterless coolant.