Hi all,

I recently acquired a 1975 Morgan 4/4 with a 1600 crossflow in it. It's been sat for quite a long time and needs a bit of a refresh, and on the way home it spat out some of it's coolant from the radiator vent. It also was popping and back firing through both the carb and the exhaust, so I've decided to err slightly on the safe side and do the following:

- New Head Gasket
- New Exhaust Gasket
- New Intake Gasket
- New Rocker Cover Gasket
- New Water Pump
- New Thermostat
- New Radiator Cap
- New Points
- New Rotor Arm
- New Distributor Cap
- New Plugs
- Fresh oil & filter
- Fresh coolant

Obviously I'll also be doing the valve clearances whilst I'm there.

I've never worked on a crossflow before, so before I dive into it is there anything specific I should know? I'm used to dealing with more modern overhead cam engines but pushrods just looks a lot less effort.

Any advice would be greatly apprecaited!

Many thanks.

could be sticking valves, check compression, valve clearence also dizzy cap for tracking, other
than that, just leave it running for a bit to loosen things off a bit.

Keep the push rods in the right order as removed
G

Id change as little as possible and do everything systematically. The crossflow is a very simple engine thats easy to work on. The only complication you'll have is the distributor has a non standard sequence & depending on how you quote the sequence (clockwise or anticlockwise) you'll end up in a world of pain.

First I'd check the timing, do the points, rotar arm and plugs. then see if its better

Then I'd check the valves and reset them, fit a new rocker cover gasket then see if its better

Then i'd flush and redo the coolant, replace the radiator cap, then see if its better

Then i'd service the carbs / give them a good clean and check its got clean / new fuel, new inlet gasket, then see if its better.

Reality is the car needs a good service - you could do all service items at once but curiosity would make me want to know where the problem area was as this is fun car to tinker with.

Only at this point would i start looking at head gaskets and exhaust gaskets as everything you've done till this point needed doing anyway and nothing is 'lost' if you do the head gasket

Hi all,

Thanks for the advice. I wanted the car running sooner rather than later so I did the obvious things this weekend. New head gasket, exhaust gasket, intake gasket, valve clearances, water pump, thermostat, rad cap, and fresh plugs. The only thing I haven't done yet is check the ignition timing.

The car started first time on the key after the above work, however to my ear it sounds very tappety:

https://www.youtube.com/shorts/2niHUkNJLCE

The valve clearances were extremely tight when I first checked. I couldn't find a decisive source for clearances so I increased them (by a significant margin, couldn't even get the 0.05mm feeler gauge in to start with) to 0.25mm on the intake and 0.30mm on the exhaust, though looking around now I see that the exhaust valve might be too tight still as some sources say 0.50mm.

Can anybody confirm the correct clearances?

This work has seemingly fixed the coolant issue and has made the engine run very significantly better; no backfires and a stable idle!

Many thanks again!

[Edited on 6/7/25 by computid]

I'd suggest buying a timing strobe (about £15 of ebay) and some new points and capacitor and set the timing correctly, it will make a huge difference and ensure you don't getting knocking or worse. Personally I prefer to tune the engines slightly rich just to help keep them cooler, yes you lose some performance but I'd rather that than hole a piston. Sounds like you could do with buying a Haynes manual for an old Escort, the older the manual the better as they have more detail, I see they have digital copies now for £27.

linky

Valve clearances ( set cold )

Inlet ... 0.010 in

Outlet .. 0.022 in

"I've set a random tappet gap (i went for spark plug dimensions because...?) but now my car rattles; what could it be?"

Slightly more useful and less irreverent reply... From memory the gap sounds right as mentioned above but also be careful not to go too tight as it'll play up when hot.

[Edited on 12/7/25 by adithorp]

10 thou inlet, 22 thou exhaust....as long as you still have the original Ford Camshaft....when the engine was modified (different camshaft fitted) the clearance needs to be set to the recommended gap suggested by the cam-manufacturer.

this said....please take care that the ex/in valves will change from 2nd to 3rd cylinder.