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102hp finally

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57_BN4

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So after a weekend running the engine I have finally achieved the 'factory' 102hp figure. The factory torque figure of 142lb at 2400 is purely dream numbers, the closest I can get is 128lbft at 3900.

The first runs I did in September last year gave about 80hp and the peak now is up to 106 so a 32% increase isn't bad.

Specs are now:
BJ8 cam grind
9.3:1 c/r
deshrouded inlet valves and de-beaked combustion chambers
lightly cleaned up ports
hardened exhaust seat inserts
K-line valve guide liners
Teflon Chevy guide seals
Total Seal gapless rings on standard pistons/sleeved bores
index ground crank with pistons coming flush with block at tdc
lightened flywheel
all rotating parts balanced
stock carbs
stock exhaust system

Joy of joys it didn't leak oil! Well ok there was a little drip from somewhere around the front pulley seal so I'll have to look into that. The gearbox synchros worked perfectly too.

second%20runs.PNG

This is the last five runs (right click and view image to get full size). Crankcase fuming was noticeably less towards the end so I think the rings are still settling down. Compression pressures were 135psi on all except 5 which has 130psi

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Unfortunately the BJ8 cam grind has given it a bit of an idle lope which I don't dislike but isn't quite what I was after
<embed src="https://www.youtube.com/v/N3PTRQ7y1_Q" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"> </embed></object>


So this brings the end of mechanical work save for painting the engine which is a pretty good milestone. Next task is to install the engine into the new chassis and start on panel alignment work.

Andy.
 
Always interesting to see the recorded effects of modifications as well as comparisons to factory figures, did the torque keep going up with engine mods, or was it higher with the stock cam?
 
Torque was up with mods, original was about 113lbft at 3500rpm and this time 128lbft at 3900. Not 100% fair comparison as the first tests were done with an engine with some miles on it.

It was interesting that power hit a brick wall at 5050rpm so maybe that is the limit of the valve springs (NOS).

Andy.
 
A very impressive test and set up. I would be nice to see all the various Healey engines compared on your rig. You have the two-port head, supposedly the 6 port is much better. I wonder how much. Bad breathing would have the most effect at higher RPM, perhaps that's the source of the brick wall at 5000 RPM...

Thanks for sharing!

Bill.
 
Thanks Bill. Yes I'd like to know the difference between the later head too and I'd happily loan the rig to anyone wanting to test an engine. Except I'm in NZ which makes it a bit hard. I'd be happy to pass on the info on how to make one if anyone is interested, it is actually quite simple.

It still has me stumped as to why they'd make a cylinder head that is so wrong. To say not needing a manifold was a cost saving is a limited argument as on the A95 sedan it got a manifold connecting the inlet holes to a tiny downdraft Zenith carb, and on the A105 sedan it got a cast ali air manifold connecting the two SUs to a single air cleaner. Amazingly the same head continued on the 3000cc sedan engines too and they claimed it made only one more hp.

Andy.
 
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