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Post by Zed on Feb 25, 2018 10:49:22 GMT
£600 excluding carb and under tins. Sold the 123 dizzy so put the flamethrower back on. Fair price depending on what's knackered. What size oil pump? Too much pressure and the oil bypasses the cooler...too much in the bearings and the oil looses it's slip. VW had it right. See - I'm dying to know!
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Post by razzyh on Feb 25, 2018 10:51:22 GMT
£600 excluding carb and under tins. Sold the 123 dizzy so put the flamethrower back on. Fair price depending on what's knackered. What size oil pump? Too much pressure and the oil bypasses the cooler...too much in the bearings and the oil looses it's slip. VW had it right. See - I'm dying to know! Funny you say that as I’ve always thought the oil pump was the catalyst. I’m not sure why Paul binned my original pump as to me it was fine. He put a modified type 1 pump on.
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Post by Zed on Feb 25, 2018 11:25:16 GMT
Fair price depending on what's knackered. What size oil pump? Too much pressure and the oil bypasses the cooler...too much in the bearings and the oil looses it's slip. VW had it right. See - I'm dying to know! Funny you say that as I’ve always thought the oil pump was the catalyst. I’m not sure why Paul binned my original pump as to me it was fine. He put a modified type 1 pump on. Do you remember the make or the "size"? What oil pressure when cold? It is a bit mad abandoning the stock pump which is just better all round, a posh semi-sealed pump with bearings each side of the gears! Mine max cold pressure no more than 60psi at any revs with 20/50 oil, 42psi when warm and above 1500, min about 20psi tickover warmed up. Spot on I'd say.
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Post by Zed on Feb 25, 2018 11:28:50 GMT
With hindsight, my 2020 wouldn't cruise up motorway hills without getting too hot and I wish I could remember what oil pump it had. Stock relief springs and oversize pump probably!
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Post by razzyh on Feb 25, 2018 19:53:42 GMT
Funny you say that as I’ve always thought the oil pump was the catalyst. I’m not sure why Paul binned my original pump as to me it was fine. He put a modified type 1 pump on. Do you remember the make or the "size"? What oil pressure when cold? It is a bit mad abandoning the stock pump which is just better all round, a posh semi-sealed pump with bearings each side of the gears! Mine max cold pressure no more than 60psi at any revs with 20/50 oil, 42psi when warm and above 1500, min about 20psi tickover warmed up. Spot on I'd say. No idea on size and can’t remember psi I know when warm at tickover the gauge registered 0 didn’t even move 🙄
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Post by Zed on Mar 28, 2018 7:12:41 GMT
Do you remember the make or the "size"? What oil pressure when cold? It is a bit mad abandoning the stock pump which is just better all round, a posh semi-sealed pump with bearings each side of the gears! Mine max cold pressure no more than 60psi at any revs with 20/50 oil, 42psi when warm and above 1500, min about 20psi tickover warmed up. Spot on I'd say. No idea on size and can’t remember psi I know when warm at tickover the gauge registered 0 didn’t even move 🙄 10.3:1! Who'd have guessed? Me. I wonder how many of these engines could now be saved with a few £ of shims. Peasoup's for starters, but there are probably many more. This was no build error, the builder has poo poo'd my fuddy duddy 8:1 thinking on this issue many times both on line and privately. What can you do though? He's an engine builder, I'm an enthusiast, who are people reading going to believe? As Jake Raby would say, and has, "I stopped arguing with fools on the internet when I realised 90% of onlookers couldn't tell who was the fool". Something like that anyway. I don't know enough to build air cooled engines professionally, but at least I realise that I don't know enough.
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Post by pkrboo on Mar 28, 2018 7:44:52 GMT
No idea on size and can’t remember psi I know when warm at tickover the gauge registered 0 didn’t even move 🙄 10.3:1! Who'd have guessed? Me. I wonder how many of these engines could now be saved with a few £ of shims. Peasoup's for starters, but there are probably many more. This was no build error, the builder has poo poo'd my fuddy duddy 8:1 thinking on this issue many times both on line and privately. What can you do though? He's an engine builder, I'm an enthusiast, who are people reading going to believe? As Jake Raby would say, and has, "I stopped arguing with fools on the internet when I realised 90% of onlookers couldn't tell who was the fool". Something like that anyway. I don't know enough to build air cooled engines professionally, but at least I realise that I don't know enough. Yes 10.3 just as you said it would be. Not a massive surprise!!
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Post by Zed on Mar 28, 2018 8:09:29 GMT
10.3:1! Who'd have guessed? Me. I wonder how many of these engines could now be saved with a few £ of shims. Peasoup's for starters, but there are probably many more. This was no build error, the builder has poo poo'd my fuddy duddy 8:1 thinking on this issue many times both on line and privately. What can you do though? He's an engine builder, I'm an enthusiast, who are people reading going to believe? As Jake Raby would say, and has, "I stopped arguing with fools on the internet when I realised 90% of onlookers couldn't tell who was the fool". Something like that anyway. I don't know enough to build air cooled engines professionally, but at least I realise that I don't know enough. Yes 10.3 just as you said it would be. Not a massive surprise!! I expect he's monitoring the TLB thread, I hope he takes it on board but I suspect he may think he's right and it's dodgy parts to blame, he can be quite stubborn.
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Post by razzyh on Mar 28, 2018 8:12:06 GMT
I do wonder if Paul’s been looking in at that thread 🤔
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Post by razzyh on Mar 28, 2018 8:13:42 GMT
Yes 10.3 just as you said it would be. Not a massive surprise!! I expect he's monitoring the TLB thread, I hope he takes it on board but I suspect he may think he's right and it's dodgy parts to blame, he can be quite stubborn. To rebuild something 4 times & numerous other engines, he’d be mad not to listen. How can you lower CR without shims presumably different cam or pistons?
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Post by pkrboo on Mar 28, 2018 8:28:08 GMT
I expect he's monitoring the TLB thread, I hope he takes it on board but I suspect he may think he's right and it's dodgy parts to blame, he can be quite stubborn. To rebuild something 4 times & numerous other engines, he’d be mad not to listen. How can you lower CR without shims presumably different cam or pistons? Cam doesn't affect CR, it's pistons, head chamber size, deck height that does
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912
Junior Member
Posts: 81
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Post by 912 on Mar 28, 2018 8:33:44 GMT
I’m sure he’s looking, Be difficult not to, I thought compression to high too, pea soups went back to have it reduced, wonder by how much? . Pea soups however didn’t sound like Razzyh’s but then pea soup didn’t drive it a great deal. I only know enough to not go to far from stock, easy peasy then
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Post by Zed on Mar 28, 2018 8:59:36 GMT
To rebuild something 4 times & numerous other engines, he’d be mad not to listen. How can you lower CR without shims presumably different cam or pistons? Cam doesn't affect CR, it's pistons, head chamber size, deck height that does Cam does affect dynamic CR, so the more overlap you have, the higher static CR you need to obtain the same dynamic CR. So I've read. But a cam that needed 10.3:1 static CR would only be fit for the drag strip and the engine it was fitted to would need constant rebuilding and/or short burst use with high octane fuel.* The cam in Ray's engine was so mild, a stock static CR would have been the way to go, easily achievable with head work or shims. It's a mistake from my recent experience to worry unduly about tight deck height, mine's around 4mm! If the heads had been scooped out to obtain the CR there would be little or no squish area left anyway and the high deck gives the burn more chance of NOT leaving unburnt fuel around the perimeter to pink and burn away the top corner of the pistons. I believe that was Rob's thinking for mine. *That's my current understanding, though unlike some people, I accept that I still have a lot to learn.
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Post by chad on Mar 28, 2018 10:08:00 GMT
I seem to remember that a long time ago, when I was looking into getting my MGB tuned, a CR of 10 or so was the province of semi-race engines and this was when 5 star was freely available.
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Post by Zed on Mar 28, 2018 10:35:27 GMT
There's a possibility the Patrick has miscalculated the CR a bit. Over 10:1 is so high it's difficult to believe.
If I put the numbers into an engine calculator, stock 2l heads are approx 50cc, 71mm stock 2l crank, 96mm b&p and 10.3:1 CR, I get 0.74mm deck height and that's not allowing for the dish in the piston top.If this was 5cc, the deck would be zero, I can't imagine him building that.
Maybe my googled head ccs are for vw heads,not amc ones with the shelf. A 1mm shelf adds 7.2ccs to the head volume, so to still arrive at 10.3:1 the pistons would be coming out of the barrels by 1mm ish. Something is wrong.
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