The engine builds.

[Keith Clements]

This topic will try to bring together the work done to try to get an engine together for racing.
This started with trying to use the parts originally from Mike Smailes and progressed to using an engine supplied by Peter Leopold and moved on to parts put together onto a block supplied by Scott Renner.

The Smailes block had been extensively welded and so was distorted and also weak where a weld had not properly fixed a crack such that it cracked on assembling the head. Some of the work is explained here. viewtopic.php?p=45994#p45994
Wills rings.
Flywheel
oil feed pipe, balance pipe
valves and ports
But these heads were lent to Julian Crossley for the Goodwood meet, where a con rod let go and damaged one combustion chamber. So two valves were replaced by Julian's mechanic. See later on what we discovered on fitting these onto the new race engine.
From the build of the Smailes block we used the crankshaft and con rods, pulley and oil pump drive, aluminium flywheel with matching pressure plate that is smaller diameter than standard. The friction plate is the new style supplied by Harry. Pistons were sourced from Fiat supplier in Italy. Keith supplied an oil pump with new gears, timing chain and gears, rocker gear fitted with new shafts.

The Leopold block also had extensive issues.
It had been newly built by the previous owner but never run. It had been quickly commisioned after aborting the Smailes block build to try to get a spare engine ready for LeMans.
Some of the work will be explained in subsequent posts in this topic, but following in quotes is the relevant paragraph from the Le Mans 2023 topic.

The previous post was about getting the spare engine working. This took Amy to the Centenary rally but broke down in a cloud of steam on the M62 on the way back. On return we investigated what had happened after Amy reported lack of oil pressure. Oil pressure was ok when first started after return but there was a ticking noise. This was cleverly diagnosed by Scott when touching a push rod as the rocker was moving from side to side. Investigation showed poorly reground tappet faces, so another rocker assembly was put on on both sides. Noise gone, The oil was black so we thought we would take the sump off. This showed poorly prepared con tods with grinding marks across them. A decision was made to take out engine. So you drain the water right? Undo tap ... no water, poke rod up hole .... dust. Put water in radiator ....water came out of core plug.....no core plug. Now I have a lot of core plugs but none fitted .. It looks like the factory had fixed an issue with a bigger plug. So on line to find one.

There was then a 2 week rebuild of this engine which had numerous issues mainly caused by the new block castings which had been machined with the crankshaft centre line a 1cm lower than it should be!

The discovery that the rockers and the con rods had been badly ground created the need to rebuild.


The Renner block was extensively checked and built up with components sourced from many places. Some of the work is explained here.
viewtopic.php?p=47650#p47650

This topic will continue the stories on each block but it can get confusing as in places we were working on all three engines at once. Some components that had been put together to build the Smailes engine were subsequently used on the Renner block.

Since for much of the time Neil, Scott and I were working in the Gulag for a month separately I am hoping they can add to the story on the many things us old Jowett sages learnt.

[Keith Clements]

Neil, Bill and Scott busy checking components and cleaning them up.

Cleaning up the oil feed hole on the crankshaft

The Leopold engine with my Dellorto carbs attached via a pair of adaptor plates I manufactured.

The oil had run very hot on the M62 and was black and this main bearing suffered.

Well this was an interlude from the Gulag with some respite in Gauntanamo down at Peter's fitting out the race car pedal area.

The crank out of the Smailes engine required some fettling as one bearing surface was not quite parallel through poor machining.

Extensive fitting and measuring gap with Plastigauge eventually got a rotating crank.

The Leopold engine was fitted with new socket con rod bolts. As bought the bolts need work on lathe to make the socket head into a cone to clear the liners. They also need shortening and the holes in the rods need opening up slightly.

Neil had brought bearings from NZ and modified them to fit the new race engine.

The previous and following pictures show when we noticed the lowered centre line of the block as the head gasket was not in its usual place.

Pushing the new shafts into the rocker assembly. Those supplied by JCS needed some fettling on the lathe to get them to fit.

The original Jowett push rod was much heavier than the new pushrods manufactured to Scotts specification in USA.

Scott had brought over push rods manufacture to his specifications but we had made a mistake in estimating the length. They were too long as the lift on the new Piper cam is so large. This is the first modification.
The second was when we discovered we could not use the new followers and needed to fit the Jowett followers and thus change the ball ends over and use the Jowett ball ends. Much lathe work was required to make these mods on the push rods.

The original Jowett cam follower was much heavier than that used by Julian that we planned to use for the new engine. There was an incredible sequence of frustrating tests lasting a week to find out why we had no oil pressure when cranking the engine. It was discovered that these followers were too short and exposed the oil gallery in the Renner block. Later series 3 blocks have the oilway in a different place. Three old sages learnt something more about Jowett engines.

The fillet radius on this machining cvlose to the petrol pump face was increased on this common point of cracking.

So we had started the Leopold engine in the test bed and tried to put the engine back in Amy's SC, but it would not fit. Much frustration only to discover that because this block had a lower centre line for the crankshaft the starter motor needed grinding off to miss the Jup chassis. This was also done on the spare starter motor as we had doubts that we may have issues with this tight motor. However, after the run to Le Mans the tightness had freed up.

The new valves supplied by Julian to replace the ones damaged in the head had a different collet location. The original valves needed replacement to accomodate the lighter valve springs and retainers. The exhaust and inlet valves had been made by Race Engineering Components and were Pinto exhaust valves which was most confusing as the ones destined to be exhaust valves had to be machined down, whereas those destined to be inlet valves could be directly fitted. Much delicate machining was done by Neil to fit these.