[Healeys] Rebuilt Engine Compression

[Patrick and Caroline Quinn]

G'day

Most will remember from about a month back, that no matter what was done, the newly rebuilt early six-cylinder engine of the BN3 refused to start. New points, condenser, etc etc didn't help. We even towed the car up and down our very quiet road and all we managed to achieve was 65lbs oil pressure. The cylinder compression for each cylinder was between 0 and 5lbs.

Needless to say, there was much scratching of heads, but to no avail.

So the car was winched on to a trailer and taken away to a friend's place for some serious fettling. However beforehand I removed the radiator, water pump, hoses and so on. This is no mean feat in the BN3 as most of the radiator (actually the same design as in our Healey Duncan) sits under the shroud with only the rear of the header tank sitting out into the engine bay.

As many said, it had to be the timing, meaning that the timing cover was to be removed. We had visions of removing the carburettors, exhaust manifolds, engine mounts so that the engine could be tilted to gain access to the crankshaft pully nut. But no, as for once there was a real plus in having a DHMC car as apart from a single horizontal bar between the radiator and the engine, the cross braces and everything else was removed to fit the six-cylinder. Even the horizontal bar has been cut away so that the shortened fan blades fit.

The crankshaft nut came away, as did the harmonic balancer and the timing cover.

The nice, pretty and new vernier timing chain was fitted incorrectly. Don't ask me how as it remains a mystery. Everything back together, except for the radiator and its compatriots. Tickle the chokes, pull the throttle and press the solenoid button. Bruum! Away it went.

Since then the cooling bits have been reinstalled and flushed, tappets done and the engine runs very smoothly due to the $$$ spent on balancing. Next is a little panel work and my recommendation is to never try and squeeze a six-cylinder engine through a 100 bonnet opening.

Many thanks to everyone who responded.

Hoo Roo

Patrick Quinn
Blue Mountains, Australia

From: Patrick and Caroline Quinn
Sent: Monday, June 12, 2023 3:41 PM
To: healeys at autox.team.net
Subject: Rebuilt Engine Compression

Hello

No amount of churning over with a new battery will induce the BN3's rebuilt engine to fire. Even towing the car up and down the road failed to instill any life into the engine.

Everything is spot on - timing, spark and fuel.

Anyone have an idea as to what the compression be on a rebuilt engine should be?

Many thanks

Patrick Quinn
Blue Mountains, Australia
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