A little bit of knowledge is a dangerous thing

[paulk]

Our 1098cc engined 1959 2dr goes like stink.

It pulls like a train and seems to use petrol at a reasonably light rate (in previous car this engine regularly hit 46mpg)

All seems normal, standard head, 1.25" carb on standard (awful) combined inlet and exhaust manifold into tiny, standard, exhaust.

Anyway I've been slowly looking over the engine with an Idea to improve it slightly with a few bits and pieces.

I've got another distributer as the existing one has a broken suction advance unit and top bearing is shot. As an aside current strobe setting (as I found it ) is about 15deg?

I'm sourcing a new timing belt and later tensioner as the front end is a little rattly.

Also sorting out alloy inlet and (eventually) 3-1 exhaust.

Anyhoo i've fitted the oil guage and that shows a nice 60psi at full chat with a reasonable level at lower engine speed.

As a further check I (finally) did the engine compressions yesterday.
1 130psi
2 125psi
3 120psi
4 130psi

I'm now confused as these seem really quite poor.


Part of me thinks just run her while she's going and do all the tune ups on another engine so I've got a straight swap at a later date.

The other part of me thinks if the engine is acting like this and doesn't seem to use any water or oil then ignore the pressures and just carry on as if all is well.

Your thoughts would be apprieciated.

Should probably say engine is an alleged rebuild (bore out by 20thou and awful paint job , where it isn't rusty)

[PSL184]

Do the compression check again but put a little oil down the bores. You will most likely find that it is just the valves that need re seating as from what you describe the botton end does sound healthy....

[bmcecosse]

Compressions are certainly very low - but you don't know how good/accurate the gauge is! Was the test done with hot engine, fully charged battery, all plugs out - and throttle propped open ? The readings are all similar - which is a good sign.
If it's not burning oil etc - and you are happy with the performance - I say leave well alone! It doesn't have a timing 'belt' by the way - just a good old chain. Certainly change the vacuum advance unit - that is necessary for best performance and economy.
Accumulate parts as they become available at the right price -but aim to put them on a 'new' engine - and just let this one run!

[Peetee]

My advice would be to leave well alone and get busy with modifying that sweet spare engine we got for nowt. If it turns out to be less than what you have, then at least you can go back to the way things were.

[paulk]

Ok I'll try the test again cos it definatly wasn't all plugs out, throttle open.
But to be fair battery was fully charged and engine warm not hot.

It doesn't have a timing 'belt' by the way

Ooops I should know better than that.

I'll give it another go.

[bmcecosse]

Oh well - you'll get much better result with ALL plugs out and throttle open. Engine hot to ensure easy turning - and thin oil - and battery well charged!