1965/67 Hillman Imp pick-up (half an Imp)

So am doing a mock-up/dry-run on the engine-assembly.

My 'new' super-rare 107 Sport head came with no studs etc in it so I set about moving them from my 'original' 533 head to the new one.

I got as far as transferring the water-temp sender when I realised it might be better to rob the bits off a head I will definitely not use. I'm starting to think it would be good to have the head that came with the car functional. Despite being 'wrong' it's more original to the car than the new one.

Anyway a long time ago I bought a very cheap early head for the project.

It seems to be in nice condition and the stubs for the water-hoses are brass instead of the later steel ones plus the studs for the manifolds & head are as-new.
I therefore put them in the new head.

The studs came out very easily with a couple of nuts locked on them. Makes a change with steel in alloy so am not complaining.

The hose-stubs are a bit tighter so I think I will get the old oven on the go to warm the head before taking these out.


new head has no fittings in it




533 head and manifolds dug out to steal parts from



some items that need transferred to bare head



here goes



water-temp sender came out fine


1st item transferred to new head



manifold studs needed


spare (128) head has all the studs I need



studs came out very easily


studs in new head


So today I will transfer the other bits over including the stubs for the water-hoses. These are supposed to be hard to remove but I have a feeling the ones on the 128 head will come out fine

I was flicking through the factory workshop manual and found some useful information about the twin carb engine.

It confirms that the oil pump drive and driven gears are Tuftrided.

The piston bosses and CROWNs are strengthened and the gudgeon pin bore reduced - The piston grade diameters are different to the standard engine to provide larger bore clearance.

The later L4 prefix standard engines have the same piston assemblies as the twin carb.

Yes I saw most of that info in the WSM but not the bit about Tutrified gears. Your manual in mb a different edition from mine.

The piston differences are so small it's hard to measure them but there is info in Tim Millington's book which advises the heavier pistons have 7101025 cast inside them.

Mine have this but iirc the info in the parts list isn't quite the same. Can't be bothered re-checking it just now.

Well I'm somewhat amazed

A few days ago I was going on about the different spouts needed for the Sport heads. These are the connectors on the thermostat end of the head that 2o r more water-carrying hoses fit on to. This part of the engine is seldom photographed as it is hidden away in at the 'bulkhead' of the (rear) engine-bay.

I'm still not totally sure how it works, despite having had various opinions (on Facebook group).

I've been told only one of the tapped positions is used on the Sport which doesn't make full sense to me as why would they delete one of the ones employed on standard engine to replace it with a double connector in the other tapped position.

I've also been told you don't need either and someone said something about water-heating the inlet-manifold on the standard engine, despite it having no provision ofr that

All I know is that the Sport does have a water-heated inlet-manifold so I would expect that this double-connector is for that and you would still need the other (single) one for whatever that is employed for on the standard engines.

I'm pretty sure the spouts are for the heater hoses. The on on top of the head for the RH hose and you'd expect the one on side of head to be for the LH hose but it isn't as this apparently connects to bottom of radiator.

Anyway it's no big-deal and it will all become clear idc but just realised I've not got to the point of the post

So I needed the two Sport parts and a bit of scanning the WWW threw up no options and NOS parts were going to be impossible to source.

I sent a message to the guy who came up trumps with the (used) connector for oil-drain pipe to head and he said he'd have a rummage for me.

A day or less later he replied (with pics) saying he'd found four sets of used ones and could do that for £18

But he'd also found, still in bag, a NOS set and could do them for £28 posted.

Despite feeling the old ones should be pressed into service somewhere by someone I felt I had to buy the NOSers.

So they arrived yesterday and have been loosely screwed into head for pic but the thread on the head is a little bit mess-up/corroded so I'm going to run a (3/8 BSP) tap thru it before winding the thing fully home.

Interesting the bag has Chrysler on it. Without checking online I think it must be from very late 60s to early 80s as the OEM parts bags would originally have been Rootes and then, in early 80s, Talbot. Chrysler took over the Imp range in 1969 I believe so this is a 70s spare which has been on various shelves since, roughly, the same time I was born



amazing find



7100645 top and 7100644 bottom



note shoulder on banjo-fitting and hollow bolt



fitting go on top of front end of head


thread needs sorted before they can be fully fitted

Wicked

Am just going out so will reply/read it better when I get home.

Interesting about the brass one tho and also didn't realise you had a thread on G15. Will have a look

The entire 'oil drain' setup has, BITD, been sorted with braided hose.

Steel + Stress + Rusty roads....

Great project happinninn here 👍

OVIMOR

I'm always impressed by the knowledge of those who go non-standard. I just go for factory 'plug n play' option every time. Have to say I have no idea what a steam pipe is

It would make total sense that the pipe routes to the timing cover end of the manifold for an Imp so that the hose from the T'stat end follows a similar route to a non sport and arrives at the bleed pot at the correct angle.

The G15 connects the other way and loops across the rear of the car - no rad and no bleed valve - My excuse will be that I have seen too many G15 installations and not enough Imp ones

I'm going back a week or so here and have kinda forgotten some of the points I would've raised but am sure it'll come back to me as I make this post.

So basically I have my 533 head, which was on car when I got it in 1988, and a 128 head I bought years ago.

I know the 533 head has some similarities to the Sport head so it's ironic that whoever put it on my engine did away with the oil-drain.

When I started this engine-work I'd sort of forgotten the 128 head and was set to rob various bits from the 533 to make the Sport head useable but then realised the 128 was a better donor.

I guess that's what gave me the idea to make the 533 useable also. If I was to take the car back to Paisley with the engine running the guys there would be more interested if it was the one it had had in Paisley.

I'm not sure exactly how early the 128 head is but it does pose the question - what head would my car have had if it had never had the engine-transplant? And also, a new one to me - what did the Rootes Competition/Experimental dept do with the car's original engine. Or did it even have an engine prior to the one it left the workshops with? I don't think I'll ever get any light shone on that but someone must have known the answers to these questions and it's now too late to find out.

Anyway back to the heads....

There seems to be quite an array of senders used, and variations of them employed. I've not got my head fully round it but when I posted pics on Imp Facebook group people were saying that should be red and/or there where white ones too and the black ones were on/off type or I've joined the 2 oil-pressure senders together in case an o-ring blows

What am I on about? Well there are basically 3 ports:

• one on head at thermostat end
• one on head at timing end
• one on block directly below the one on head

I haven't looked into the one on block yet so will just talk about the ones on head.

On the 533 head the one at stat end was black where others were saying you'd get red or white and took a large spanner (13/16"). The bulb had Smiths Motor Accessories stamped on it and various numbers on the nut. I'm guessing it's old/original.

In the same port on the 128 head the sender didn't take any Imperial spanner but an 18mm or a 3/8 Whitworth fitted the considerably smaller nut part. This one was however red. I'm guessing it's a later aftermarket part or possibly very early due to Whitworth spanner. Who knows.

On the timing end the 533 head had an oil-pressure sender but the 128 head just had a plug. This begs the question 'how did the driver get any warning re the oil pressure?' but his is possibly where the port on block comes in. I don't know tbh but to add to the confusion my car had an oil-pressure or temp gauge fitted which was fed by another port on the block afaik.

The 128 head also came with a cam-cover which is handy. Same casting number inside as the 533 head which suggests a real rivet-picker could perhaps ID parts from late or early eras on various parts




128 head c/w cam etc


water-temp sender removed from 128 head (has red plastic indicator on it)



sender from 128 head is quite different from one removed from 533 head



18mm socket fitted 128 sender



but 3/8 Ww was also very snug fit



removing oil-pressure sender from 533 head



128 head had plug instead of sender here



shifter used on plug as no spanner fitted



plug removed



cam covers same same but different. 128 is dirty one


removing cam-chain guide from 128 head



guide parts moved to Sport head












So as I think it would do no harm to freshen-up the 533 head I took the valves etc out. No tools used. I just used the shade-tree method and bumped the collets out by putting a socket on extension over the valve-spring and smacking it with a hammer. Once you get the knack they jump straight out. Got a lot of cleaning to do and will lap the valves in.



manifolds removed from 533 head



I only have one thermostat housing and, like the steel spouts, it's not keen to let go



valves etc removed from 533 head for cleaning


533 head needs good clean