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PostPosted: Fri Jan 07, 2005 6:45 pm 
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1098cc
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I haven't read the whole thread so if this has been mentioned discard it. If you are going to bore it, find a torque plate and make sure that you have the main caps in the block at the correct torque also. This will give you better and truer bores. After you have found a torque plate find someone with a Sunnen hone and do it on that. There are no better machines than Sunnens. Drive 200 kms if you have to but use a Sunnen. A torque plate is a plate that is bolted to the block with the head bolts and has holes in it a bit bigger than the bores. When a head is put on the bores distort and by using a torque plate the bores are machined as they would be with the cylinder head bolted down. It means true clearances on the pistons all the way from top to bottom. Putting the main caps on also trues up the bores though to a lesser extent. BTW anyone got a torque plate for a 1275? If not I'll have to get one made. It is a fairly expensive piece of equipment. I am sure Vizard went into this some where, some time. CCC perhaps?

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PostPosted: Fri Jan 07, 2005 6:49 pm 
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1360cc
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Chris wrote:
I haven't read the whole thread so if this has been mentioned discard it. If you are going to bore it, find a torque plate and make sure that you have the main caps in the block at the correct torque also. This will give you better and truer bores. After you have found a torque plate find someone with a Sunnen hone and do it on that. There are no better machines than Sunnens. Drive 200 kms if you have to but use a Sunnen. A torque plate is a plate that is bolted to the block with the head bolts and has holes in it a bit bigger than the bores. When a head is put on the bores distort and by using a torque plate the bores are machined as they would be with the cylinder head bolted down. It means true clearances on the pistons all the way from top to bottom. Putting the main caps on also trues up the bores though to a lesser extent. BTW anyone got a torque plate for a 1275? If not I'll have to get one made. It is a fairly expensive piece of equipment. I am sure Vizard went into this some where, some time. CCC perhaps?


Chris, good advice......Q: would an old head milled out to allow the hone down the bores work OK... :?: :?:

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PostPosted: Fri Jan 07, 2005 7:04 pm 
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Chris wrote:
I haven't read the whole thread so if this has been mentioned discard it. If you are going to bore it, find a torque plate and make sure that you have the main caps in the block at the correct torque also. This will give you better and truer bores. After you have found a torque plate find someone with a Sunnen hone and do it on that. There are no better machines than Sunnens. Drive 200 kms if you have to but use a Sunnen. A torque plate is a plate that is bolted to the block with the head bolts and has holes in it a bit bigger than the bores. When a head is put on the bores distort and by using a torque plate the bores are machined as they would be with the cylinder head bolted down. It means true clearances on the pistons all the way from top to bottom. Putting the main caps on also trues up the bores though to a lesser extent. BTW anyone got a torque plate for a 1275? If not I'll have to get one made. It is a fairly expensive piece of equipment. I am sure Vizard went into this some where, some time. CCC perhaps?


Chris,
I always thought torque plates were gospel too. On V8s, probably is true. But Keith Calver debunked this one recently for A series, he had done documented trials in UK that have shown on an A series it makes no difference.
<edit> but, it won't hurt to use one!! :P

Mick,
Too much trouble to do that with a head, and chambers are too wide anyhow.
All you need is a nice piece of 1" or thicker steel plate, surface ground both sides. :wink:

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PostPosted: Sat Jan 08, 2005 8:46 am 
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1098cc
1098cc

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Location: Helensburgh NSW
drmini in aust wrote:
Chris,
I always thought torque plates were gospel too. On V8s, probably is true. But Keith Calver debunked this one recently for A series, he had done documented trials in UK that have shown on an A series it makes no difference.
<edit> but, it won't hurt to use one!! :P
Quote:

Kevin, I am old fashioned then, but I would still use one. I have measured how far bores have moved with one in place, though not an A series I admit. Sunnen hones are simply the best in the world, or were. I have had no one tell me any different and I still have to find one to do my block on. I know where there is one used for kart motors but he is not interested. Has Keith put his thoughs on boring to paper? I will have a look on his site. I suppose the A series not being a modern thin walled block may have some bearing on the matter. For those that want to try it the bolts must go into the block at about the same depth as they do when the head is on, so invariably you need different length bolts, or pack the originals which is most probably the easiest way around it.
Quote:

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 Post subject: Yep
PostPosted: Sat Jan 08, 2005 9:05 am 
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1360cc
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Mick,
Too much trouble to do that with a head, and chambers are too wide anyhow.
All you need is a nice piece of 1" or thicker steel plate, surface ground both sides.
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Kevin G- pilot of `70 MiniMatic 1310S sleeper..


Here's one I prepared earlier....... :lol: :lol: :lol:


Kevin, I am old fashioned then, but I would still use one. I have measured how far bores have moved with one in place, though not an A series I admit. Sunnen hones are simply the best in the world, or were.

From the Head Sales Rep Australasia - Sunnen Hones :wink: :lol:

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 Post subject:
PostPosted: Sat Jan 08, 2005 9:44 am 
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I'll just give mine to Graham Russell. :P Whatever he uses seems to work- he's getting more HP from his race motors than anybody else out here! :lol:

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