Keeping sane during the isolation lockdown

[iain1967s]

The engine in my ‘67 S is worn out... or more specifically I put it together a couple of years ago with what I thought were ‘good enough’ tolerances; the +20 bores measured wear at around 3 thou, so I just de-glazed with a honing stone and re-ringed the original pistons.

In retrospect, that was a mistake - I really should have had the block rebored +30 while it was stripped down. Sure, it ran - and although the initial compression was good, it soon became obvious that oil consumption was excessive due to bore ovalling, with blue smoke embarrassingly pronounced while driving.

I didn’t want to lose a driving season while I stripped and rebuilt the original engine over the summer months, and my rented storage lock-up has no electricity for lighting nor any heat, so working over the winter months is not viable either.

I decided the best option was to try and build up a spare S block in my basement slow-time, so that when completed it would be ready to drop in to the car along with my recently rebuilt gearbox, minimising the time the car would be out of commission.

Of course, as it turns out, I now have rather more time on my hands than expected - due to the Covid-19 mandatory lockdown in Massachusetts. So, I guess there’s nothing for it but to start a build thread...

[iain1967s]

An early break saw me able to source a thin flange S block in a good condition from 7ent, the same AEG312 type as the original in my car.

Apparently, it came from Doug Peterson, Mike Kearney’s racing partner from the Fortech Mini days. It was stored indoors for 30 years after it was machined.

It does have the original main caps and was bored +.030, and it appears that it was surfaced just enough to give a flat deck surface. It has just a little surface rust, but needs a good clean up and cam bearings fitted.

[iain1967s]

Time for a good scrubbing with a brass wire brush, followed by soaking in a gallon of CLR [Calcium/Limescale/Rust dissolving solution].

I removed the freeze/core plugs and all the brass screw plugs on the oil/water ways, then used a gun rifle barrel cleaning kit to pull helical wire brushes through all the drillings to clean out the rust and muck.

It was pretty filthy, but no significant rust and the water jacket only had some loose flakes behind the core plugs, which was easily dislodged and flushed out.

[iain1967s]

With the block confirmed as being in usable condition, it was time to begin the hunt for the rest of the specific Cooper S parts that I would need to build up a short engine.

Shopping list:

• Crankshaft: A good EN40B S crank came courtesy of Nick at min-e-bitz

• Pistons & Conrods: Used set of original S type AEG521 con rods off eBay, complete with some junk pistons

• Camshaft & followers: from MiniSpares UK

• New bearings [Cam/Main/Big end/thrusts]: from 7ent

• Front plate: from eBay UK [surprisingly hard to find state-side]

• Tinware: TBD

• Duplex timing gear: from MiniSpares UK

I already had a +30 set of ‘county’ brand [Hepolite clone] 9.75 S pistons on the shelf, in preparation of a re-bore for my original engine. So the only tricky part was changing them over on the interference fit gudgeon pins without access to a hydraulic press.

The same trick I’ve used before is to put the pins in the freezer overnight and then use all-thread or progressively shorter bolts to wind them through the piston and little end into an over-size impact wrench socket used as a die.

For the camshaft, I really wanted to stick with the same AEG510 profile that I used in the previous engine. But Mini Sport seem to have stopped selling their ST510/CA1 reground camshafts so instead I went for the MiniSpares “Evolution 1” camshaft.

[iain1967s]

With the block clean, it was time to set about refurbishing it.

I’ve never installed cam bearings before, so always good to learn a new skill. The tools are available cheap on amazon.com so I bought a set of NOS bearings from eBay and tried installing them. I originally planned to use the NOS set, but after some confusion regarding the finished bearing clearance, I scrapped them and used a set of modern repro bearings purchased for my previous build but never used.

The crank was already ground 10/10 and just needed the journals to be lightly polished with 2000 grit emery paper to clean up marks from storage. The bores likewise just needed the minor surface rust from storage to be removed with a light hone, and then the new pistons and rings could be installed - which, without the use of a ring compressor, takes more time (and fingernails) than one might expect.

[iain1967s]

Last job for fitting the camshaft was to plug two of the 3-hole oil pump threads with 1/4” grub screws and blue loctite, then drill and tap the second mounting hole for the more modern ‘A+’ type two bolt oil pump to match the slot drive cam.

Crankshaft is dropped into place, taking care to make sure the thrust bearings are within tolerance. There’s an easy way to do this without a DTI: put the main shells In the block, and then put two +3 thou thrusts in place on the center main. Try to fit the crank. If it won’t slide in, or feels like it’s tight or binding, change to std - which is what I did in this case.

Distributor drive is then installed, and we’re done with the internal assembly. Time for a lick of MOWOG green paint.

[iain1967s]

Next job will be to install the front plate and timing gear, but first I have to wait for Minispares to ship and DHL to deliver.

[Cole Liggett]

That’s looking great! Thanks for sharing so many photos with us!

[AndyPen]

Hope the basement steps aren't all that steep... and that you have a strong buddy

[mk1]

What a great post!

I have done an engine swap on my Moke this weekend, only snag is I can't take it for a drive to set it up.

[iain1967s]

Minispares order received, so the build has resumed.

First up, the engine front plate, cam retainer and AE timing chain set. Had a bit of bother fitting the woodruff keys, but some fettling with a small file soon cleaned them up. Added three shims on the crank face to get the gear parallel, so not too far out.

You might notice the camshaft nut tab washer is still flat - I won’t torque and fix that in place until I’ve checked the cam timing with a DTI - for which I need the engine the other way up. It’s just aligned ‘dot to dot’ at the moment.

The engine plate was quite hard to find - there don’t seem to be any available at the usual USA vendors, so I ended up getting one shipped over from eBay UK. It’s a 998 version, so I countersunk the two main bearing screw holes, to fit the two flush mounted allen key style screws.

[iain1967s]

Sticking with the eBay theme, I picked up this rather tired Purolator filter housing. It went for a weekend ‘spa mini-break’ in a bucket of carb cleaner, followed by some judicious wire brushing it came up pretty well. After hammering some dents out of the alloy, some etch primer and satin black it doesn’t look too bad at all.

Then I realised I don’t have a gasket for the filter head to block, so I cut one out of thick construction paper. I always use Permatex Aviation gasket sealant on all joints so the gasket is really just there to carry sealant that anyway.

Also fitted the core plugs, after getting some guidance from the forum, and bolted in a NOS water pump and an S large cast pulley.

The correct distributor drive housing arrived, after my mix-up with an MGB housing, and I fitted the oil pressure gauge takeoff and bypass valve. Currently on my car I have the adjustable version with a ball bearing, but I’m trying the plunger type this time around.

[iain1967s]

Also picked up a correct pair of convex type tappet chest covers, this time from eBay USA.

The PCV canister & cover is NOS, still in its original BMC wax cloth protective wrap, and zero corrosion to the wire wool filling so looks ready to use.

These were apparently not supplied with much in the way of paint, just brazed up and ready to prime. Getting the wax off took some effort, but after some etch primer and satin black they came up a treat.

[Toby]

Also picked up a correct pair of convex type tappet chest covers, this time from eBay USA.

Ah, so you were the one who grabbed that

[iain1967s]

Well, the S engine and 333 box are mated, not much else I can do once the tinware is installed.

The cylinder head and primary transfer gears are stuck at mum’s house in Diss, and our spring vacation to the UK is cancelled due to the virus...

[Gray]

Just as a matter of note I had a nos 12g577 breather vent and found that the tube from the cover to the can was too long to fit between the block and the bulkhead so be careful when lowering the engine in just in case. Gray

[Andrew1967]

Just as a matter of note I had a nos 12g577 breather vent and found that the tube from the cover to the can was too long to fit between the block and the bulkhead so be careful when lowering the engine in just in case. Gray

I think the longer ones are Morris Minor ones Gray.

As the tube is only brazed in, I should think it would be fairly easy to modify.

[abri]

Nice thread. In case it matters to you, the oil filter head used on the S had a switch to warn you of a blocked filter (wired to a little orange light on the speedo). Yours seems to be an earlier type without the switch.

[iain1967s]

Checked the cam timing with a DTI, came in around 102° so ordered up a 5° woodruff key as the Minispares website says the Evolution001 should be timed at 107° inlet full lift.

After fitting the 5° key, re-checked and it’s ended up at around 106°, so that should work itself out nicely once the new chain beds in to the sprockets.

Had a bit of a problem when I realized that a sprocket locking tool is needed to hold the camshaft gear still while torquing up the camshaft nut. Can’t get to Harbor Freight (local cheap tool store) due to the covid lockdown, so needs must... made my own from a bit of old bed frame flat steel and some 5/16th bolts.

Finally, measured the cam end float at 4 thou with the nut torqued to 60lbft, and it’s consistent regardless of angle of cam rotation. Haynes says 3 to 7 thou, so that’s spot on.

[iain1967s]

Well, the tinware is all painted in satin black engine enamel and fitted, so that’s as much as I can do on this build for now.

Arrangements have been made to courier the stranded 12G1805 cylinder head and primary gear over from Mum’s house in the UK. Original S type rocker gear and crank pulley/damper are also on their way, thanks to eBay.

Thanks to Roland for the metal dipstick & tube - they are quite hard to find these days, and I really didn’t want to use the later nylon type tube.

Note: Bolts on the front cover are not done up yet, I’ll need to center it on the crank pulley first.