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May 19, 2018 9:06 pm
May 19, 2018 9:06 pm
Subject: Re: Tappet clearances - why the variation?
I think I'd take any dyno figures with a grain of salt. They're good for comparative testing, but as an indicator or absolute BHP I'm not so sure. I rebuilt a Harley engine for a friend once, and, much to my surprise, it went like an absolute rocket (the reason I was surprised was that he had bought a kit off eBay, like you do, and it wasn't really the spec he wanted, as you could tell by just glancing at the big fat cam lobes). Anyway, he put it on a dyno and complained that the figures were lower than the manufacturer claimed. I gave him the same advice as above.
Anyway, I am new to Lagondas so have no experience of these interesting engines. But having read Tim Wadsworth's post, it seems that he is the living proof that .004" will work ok.
As I said earlier, though, the profiles of the rocker pads are critical to the effective cam profile. I suspect that any wear here will upset the performance.
What is the spec of your engine?
My car (EWF 99) is a hybrid - it looks like a 2 litre Speed Model but started off in life as a 14/60 saloon. It has high comp pistons & twin SU's. My cams and rockers are worn, but not terribly, and that will be another job for another day - when I get my new down-draught head from Wessex.
Right now I am trying to figure a way of sticking the dynamo on the side of the engine - I fitted a new water jacket side plate which the Club says is 'ready to fit', and in a sense it is. But after I had spent hours drilling out the snapped off bolts (a task abandoned by the previous owner), then enlarging the holes in the side plate so it would fit where the bolts had been drilled slightly off by the previous owner (who had tried to do it in situ), and then sealing it all up with RTV including fibre washers under the bolt heads, I then noticed that I was missing a couple of tapped holes in the side plate for the dynamo strap! The old plate had turned to dust so I had nothing to compare. I'm hanged if I'm taking that plate off again so that's another little challenge before I put the engine back in (good job I noticed it before I did!).
I think I'd take any dyno figures with a grain of salt. They're good for comparative testing, but as an indicator or absolute BHP I'm not so sure. I rebuilt a Harley engine for a friend once, and, much to my surprise, it went like an absolute rocket (the reason I was surprised was that he had bought a kit off eBay, like you do, and it wasn't really the spec he wanted, as you could tell by just glancing at the big fat cam lobes). Anyway, he put it on a dyno and complained that the figures were lower than the manufacturer claimed. I gave him the same advice as above.
Anyway, I am new to Lagondas so have no experience of these interesting engines. But having read Tim Wadsworth's post, it seems that he is the living proof that .004" will work ok.
As I said earlier, though, the profiles of the rocker pads are critical to the effective cam profile. I suspect that any wear here will upset the performance.
What is the spec of your engine?
My car (EWF 99) is a hybrid - it looks like a 2 litre Speed Model but started off in life as a 14/60 saloon. It has high comp pistons & twin SU's. My cams and rockers are worn, but not terribly, and that will be another job for another day - when I get my new down-draught head from Wessex.
Right now I am trying to figure a way of sticking the dynamo on the side of the engine - I fitted a new water jacket side plate which the Club says is 'ready to fit', and in a sense it is. But after I had spent hours drilling out the snapped off bolts (a task abandoned by the previous owner), then enlarging the holes in the side plate so it would fit where the bolts had been drilled slightly off by the previous owner (who had tried to do it in situ), and then sealing it all up with RTV including fibre washers under the bolt heads, I then noticed that I was missing a couple of tapped holes in the side plate for the dynamo strap! The old plate had turned to dust so I had nothing to compare. I'm hanged if I'm taking that plate off again so that's another little challenge before I put the engine back in (good job I noticed it before I did!).