Another mystery engine

Post by **edd** » Sat Nov 15, 2003 4:10 pm

I wonder if anyone can help.
The engine in my free 4 door squeeks and clangs when its turned over by hand. This i think isnt good so ill have to have it out at some point. Before that though id like an idea fo what size it is if thats possible.

It has no engine number as this has been machined off. The head is a 12g202. There is no 1100 plate on the block unlike my 1098. On the maniflod side of the block towards the front is cast c29k1. And towards the back 12A 497. These are the only numbers i can find. It has been at some time painted green over its origional red.

AS for the condition of the engine are there any chacks i can make with it still in the car? I realy dont want to run it if its going top cause more dammage.

Any help is appreciated

Edd

Post by **Willie** » Sat Nov 15, 2003 4:59 pm

You probably know that the 12G202 head is the standard one
for the 1098cc engine,but of course it could have been added.
I can find no reference to any engine which was prefixed
12A. I cannot see what you can do to check the engine
further without actually starting it(compression test etc),
The only crumb of comfort that I can offer is that if the
engine number has been machined off it is usually a sign
that the unit has been rebored( the block face is faced off
flat before the re bore is done which means that the engine
number is ground off in the process) If there are no holes
where the engine number fixing studs were then it has been
machined off. If the two holes are visible then the engine
number plate has been carefully removed! Does it turn over
freely but with definite resistance for the compression strokes??
On the handle with the ignition OFF you should hear the escape
of compression on each cylinder. If all feels fairly healthy
then you could try removing the starter motor as this can
produce some alarming noises if the bendix is sticking.

Post by **edd** » Sat Nov 15, 2003 5:16 pm

If there are no holes
where the engine number fixing studs were then it has been
machined off.

Thats aleast somthing!

AS for the 12a

Not that i think that will help either.

What size should the bores be? If i get time ill get the head of and do a rough check with a vernier. Also ive not come accros a drain tap like that one on a block before. I thougt minor ones were either a brass tap or a plug.

Edd

Post by **les** » Sat Nov 15, 2003 7:19 pm

You should be able to measure the stroke of the engine, to give you a clue, by holding a pencil down one of the plug holes and turning the engine by hand. Without looking for the info, I am assuming that the strokes are different for different capacities. If not this will not help!
Could be easier than removing the head.

Post by **Cam** » Sat Nov 15, 2003 7:35 pm

by holding a pencil down one of the plug holes and turning the engine by hand

Will that work?? the plug holes are at an angle and I don't think you could feed one down to BDC without it hitting the bore wall and stopping. Plus it would come out at an angle so the measurement would be innacurate.

I am assuming that the strokes are different for different capacities

Bores and strokes determine capacity. Mostly bores though, as a lot of the strokes are the same for the A-series, but there are differences.

Post by **les** » Sat Nov 15, 2003 7:54 pm

Yes you're right, it's not a spot on method, it is only any use if the strokes vary, the accuracy should be enough to distinguish the difference. Maybe a knitting needle would ensure reaching bdc, it could be held pretty much vertically, or a very thin pencil!!!

Post by **Cam** » Sat Nov 15, 2003 7:58 pm

the accuracy should be enough to distinguish the difference

Ah! right. I have never tried it you see................... but if it works, then it works!

Post by **les** » Sat Nov 15, 2003 8:21 pm

I've just found a few figures:
803cc-----stroke =76.2mm
948cc-----stroke =76.2mm
1098cc----stroke =83.72mm

Post by **edd** » Sun Nov 16, 2003 1:24 am

Ill give it a go and compare it with my 1098. its definately not a 803 so we shall see!

Cheers

Edd

Post by **edd** » Sun Nov 16, 2003 1:27 am

Anotehr thing i noticed earlier is that on the underside of the waterpump there are what look like a load of white crystals. Can thsi be caused by a failed waterpump and if so maybe the engines overheated.

Edd

Post by **Willie** » Sun Nov 16, 2003 8:04 am

Don't know about the crystals,if it's stood for a long time they
might be Stalagmites!! One question, do the valves operate
when you turn it over? I ask because a broken timing chain
would also 'clank' inside the timing cover. The trouble with
things like the block drain tap is that,over the years, many
original fittings could have been replaced with whatever was
available. Is the engine mated with a late(ribbed case)
gearbox??

Post by **edd** » Sun Nov 16, 2003 8:56 am

do the valves operate
when you turn it over?

Yep They all work ok

I also checked the distributer and the rotor arm turns ok.

Edd

Post by **edd** » Sun Nov 16, 2003 11:39 am

Right. I get commpresion of over 100psi on all 4 cylinders (i think my guage is broken as it doest hold the preasure it just leaks out.) The starter moter is fine and everything else looks ok. I couldnt find anything else untoward so i turned the engine over on the starter for 30 secs then put the plugs back in and started it. It started on second go (not bad). I ran it for 5 seconds and is sounds as though one of the big ends has compleatly broken up. Ill drain the oil and whip the sump of this afternoon and hopefully the isnt to much damage. Is it likely theat the crank/conrod is damaged? Ive got new bearings somewher so if the cranks ok ill fit and see what it sounds like lol.

Cheers for the help. It gives me some confidace that im on the right track.

Edd

Post by **Peetee** » Sun Nov 16, 2003 12:29 pm

Cam, can you concur that the the crank will have a number on that would help identify the engine?

Post by **Cam** » Sun Nov 16, 2003 1:47 pm

Possibly so, although I can't say what the numbers are. I think if you take the big end caps off then you should be able to see the problem. But if it's that bad then the crank journals may be scored, in which case you will have to remove it and get it reground and buy some oversize bearings.

Engine identification once the sump is off should be easy as you can measure the stroke (straight up) and measure the cylinder bore.

Post by **edd** » Mon Nov 17, 2003 11:29 am

Hads the sump off and the engine is a 1098. As for the big ends well there abit scored!!

and a funny shape?

Is this becauuse of overheating / lackof oil?

Cam you were rigt the crank is verey badly scored. The bearings have 4d 030 on the back does this mean 30 thou oversize?. If so would it be better to get a recon crank instead? as im dot shure if all the scoring could be taken out by grinding.

Cheers for the help

Edd

Post by **Cam** » Mon Nov 17, 2003 11:39 am

Erm........yes mate, probably best to get another crank. MAYBE you could get away with another 10 thou, but maybe not, in which case you have wasted money on a useless regrind.

There should be plenty of cranks about. If you can't get an exchange one easily (which you should ba able to) then just get a semi-decent original 1098 one and get it reground. I got away with 10 thou on my last one!

Post by **edd** » Mon Nov 17, 2003 12:06 pm

How much is it usaual to pay for a regrind?

Edd

Post by **Kevin** » Mon Nov 17, 2003 12:06 pm

If you are on a tight budget a good second hand engine may be a better option.

Post by **Cam** » Mon Nov 17, 2003 2:47 pm

Well I have only really used MED engineering in Leicester who are expensive but VERY good (race A-series specialists). they charge £50 for a regrind but I have seen £30 from other places, but if you shop around you might get even cheaper.

Have a look at:
http://www.med-engineering.co.uk/crankshafts.htm