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Post by Roodog on Feb 26, 2013 16:50:21 GMT -5
I have a block sitting here that I was going to rebuild. I went to the bug shop in Denver and they tried to talk me out of building a 1648. I was told that the walls of the cans tend to overheat because the boar on the case is the same as stock and the walls are thin. That is the reason why I was building a 1648. The block is pretty new and does not need line boared or can bored. They also told me that it would add about 40cc's and not at all noticeable. I was told to go for at least a 1776. I was just wondering what others have found.
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Post by centralvalleygter on Feb 26, 2013 17:11:27 GMT -5
Generally speaking as long as you do not go more than a 90mm bore, you will not have problems with overheating due to thin cylinder walls, that means going up to a 1776 on the stock bore is the maximum. The 88mm cylinders uses for 1648 should not be any problem. I have been running a 1648 in mine since the mid 80's without any problems. I have dual Kadrons, Pertronixs ignition module and a mild cam (with high performance valve springs). This combination of parts makes a clearly discernable difference in terms of acceleration and top rpm available over stock .
Warmest Regards,
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Post by Gary Hammond on Feb 26, 2013 20:33:34 GMT -5
Hi Roo and Steven,  I tend to disagree with running 88mm slip-in cylinders. They are pretty thin' and will most likely overheat and warp causing power loss and blow by. This is especially true if you raise compression, run a hot cam, and run dual carbs or EFI.  IMHO 88mm slip-ins are a waste of time and money in a stock engine, and are unsuited for high performance use. I may be wrong, but aren't the 90mm jugs all machine-ins?  I'm running 88mm machine-ins for a 1679 cc displacement. They have very thick walls and have held up quite well in my modified engine. I originally got them for the experimental "internally supercharged" engine I built up. Gary Hammond,   |
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Post by Gary Hammond on Feb 27, 2013 15:17:09 GMT -5
Hi Roo and Steven, Your numbers didn't sound right to me so I consulted some of my reference material. Don't know where you got the 1648 engine size from, but the 1641 has 87mm bore and stock 69mm stroke. The 87mm slip-in jugs are ok, but only give a 3.5% increase in displacement. They are reliable enough, but add very little extra power for the money. If you need to replace the pistons and jugs anyway, this might be a good way to go on an otherwise stock engine.  The stock "1600" has an 85.5mm bore with 69mm stroke which yields 1584cc's. The 88mm bore and stock 69mm stroke yields 1679cc's. The slip-ins are pretty thin walled and not usually recommended. The 88mm machine-ins are very durable but still don't give a big increase in displacement, so usually are bypassed in favor of the 90.5mm machine-ins for extra displacement (1776cc's) at the same cost as the 88's. Steven, are you sure you have 88's and not 87's? Either your 1648/1641cc size is wrong or you've got 87's. Gary Hammond, |
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Post by centralvalleygter on Feb 27, 2013 15:47:34 GMT -5
Gary,
You are right, I have 87's which result in 1641 and not 88's. My brain slipped a gear and I didn't check myself before I wrote the response.
Warmest Regards...
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Post by Roodog on Feb 27, 2013 17:32:13 GMT -5
I'm sorry guys, sorry to make you all look up everything. I ment 1641... I was out painting a go cart and my brain was a little jumbbled. I have a almost new block that I think has less than 40 hrs on it. I had it in a buggy that I had and my wife wrecked it at the sand dunes. When this happened a bar off the roal cage bent down and went threw the fan and between two cans. I was going to try the 1641 because I didn't need any shop work on it. Only pistons, cans and one head.
I like the 1776 due to the best bang for my buck from what it sounds. I'm just wanting something more road worthy for my bradley than the 1955 that I have for it now. It always seems like I'm having to fiddle with it. Just seems like the 1600 is a good little engine but doesn't have the push I need to get around here expec in the hills.
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Post by Gary Hammond on Feb 27, 2013 22:40:35 GMT -5
Hi Roo, The 1641 should be fine if you don't want to machine the block. Gary Hammond, |
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Post by Roodog on Mar 2, 2013 12:41:43 GMT -5
Good news I found a block for 150 bucks. I'm going to try the 1776. It looks like it is in good shape but does need line boared. I was told with the webber 36 or 38 I cant remember duel carb setup that I have I can only use a engle 100 cam. I have a 110 sitting here but it will not work. Does anyone have any ideas? What will happen if I use it?
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Post by Jeff Troy on Mar 2, 2013 21:11:31 GMT -5
Hi, Roo,
I've had my original 1600 DP in my Bradley since I built the car in 1976. In 1990, at 340,000 miles, I rebuilt the engine and changed to the 87mm jugs. Performance seemed quite a bit snappier, but I also switched to dual Kadrons and a Berg exhaust collector/muffler system, all of which contributed to the gain.
Now, at 645,000 miles, I am building a new engine for the car. This time it's a 1776, and for all the reasons you've read above. Primarily, it's the largest piston/cylinder arrangement that retains a reasonable wall. I don't race and I don't push my car -- ever -- so the 1776 seemed like the way to go.
As an aside, I'm also just finishing a Fiberfab MGTD Replica, and I chose the 1641 as the right street engine for that project. I wasn't looking for any extra power (it's a TD, dude), but no machining was required and the jug/cylinder sets were no different in price between the stock 1600s and the 1641s. I haven't finished the car yet, but the engine has been fired and runs very smoothly.
With roughly 300,000 miles on my 1641 rebuild, I can attest to the streetabilty of the 87mm jugs. Just do good work and follow the torque guides. Best rebuild book I've seen is "How To Rebuild Your Volkswagen Air-Cooled Engine" by Tom Wilson.
Good luck and warmest regards,
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Post by Roodog on Mar 3, 2013 11:46:39 GMT -5
Thanks for the info. I to don't push my cars other than in the hills here. I have seen that book by tom wilson at the bug shop and was going to pick it up. I think I am going to put a 1641 together with my first block and go for the 1776 with my second block. I hope that I can get the milage with my engines that you have. I plan on driving it to the falls some year for the Bradley get together. It is a four day drive from here but I think it would be cool.
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