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Post by andrew on Sept 18, 2008 7:49:21 GMT -5
Andrew, think of removing the head as untorqueing the head. Loosen the bolts in the same sequence as used in tightening the head, loosening each bolt about 10 ft pounds. After they get down to about 40 ft lbs, the bolts can be removed in a single step. Takes a little longer, but I think is worth the time the lessen the chance of warping. Bill Now this is the kind of information that is great. It is fine to understand how the engine works and what has to be done but how it is done is far more important. I would love to know how to do this and doing it will be rewarding. I love to learn but I fear it may be a vast extension beyond my ability. Am I better to employ a Sunbeam God to do the work and do the full rebuild (the do it right camp). Then the questions are: do any of the Sunbeam Gods have the time and would they care to do the work, can I get an idea of cost? Would a Sunbeam God care to be a mentor? Comments are welcome because I would not have followed this procedure of removing the head and then I would have been in a mess. It is fine to ask the questions but if you don’t know what questions to ask, will it be done right? Some may even say I should not be given the privilege of taking on such a project on without the proper education. Andrew
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Post by Jim E on Sept 18, 2008 9:18:44 GMT -5
When I slack head bolts usually just point the ratchet handle in the same direction for each bolt and loosen them around a quarter turn each, repeat until they are all loose. This is a good idea if you are going to bolt the head back on with no machine work or if you are having head work done because it may lessen how much the head is warped and if the head is to be milled it will mean less material has to be taken off to get it flat. Which means the head will have more mills left on it. At least I tell myself that. Then if you plan on cleaning and bolting it back on you want it to be as flat as posible. You want to check the head for flatness before putting it back on. Clean the head of gasket material. Carb cleaner or the like I sometimes use WD 40 and a body sanding block with fine paper. Then take a straight edge and lay it across the head now try to get a feeler gauge under the straight edge, do this all over the head where the straight edge and head surface come together. More than 4 thousands is questionable, I usally start with a 3 thousands and see more than 3 and you could not get a good seal.
Use the same method to clean the top [deck] of the block, but here you want to stuff rags in the bores to soak up the stuff and keep things fairly clean.
got to go more later
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blue
Junior Member
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Post by blue on Sept 18, 2008 9:42:58 GMT -5
Jim, when you try to remove an overhead camshaft, have to beat it out with a three pound hammer and find the head is warped 3 thou end to end, you get religion real fast. Grinding won't do any good as the cam bearings would remain out of alignment. Had to straighten the head by placing a shim (old head gasket) under one end of the head, place it on the block and tighten the $hit out of it. Finally got it down to about one thou, which allowed the camshaft to slide in smoothly. That was on a cast iron head that weighted 44 pounds. I shudder to think what could happen to an alloy head.
Bill
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Post by jimstone on Sept 18, 2008 12:27:44 GMT -5
andrew: you should do whatever will make you most comfortable from a time and money perspective. you certainly can't beat the work of one of the Sunbem Gods; they can do it faster and more efficiently than you can. they are also less likely to make a stupid mistake that will come back to haunt you. on the other hand, you CAN do this yourself, with the help of the board. i had never done it before either, but asked lots of questions and muddled my way through it. IMHO,anyone who has done as much work as you have already can handle a rebuild. I also think Jim's quick and dirty fix is worth considering, especially since you don't want to invest much money in the car right now. of course, you won't know until you pull the head, but now you know how to do that. BTW: I miss the old forum, but just discovered that this one works very nicely on a PDA. the regular one doesn't, at keast not on mine.
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Post by andrew on Sept 18, 2008 12:47:15 GMT -5
you CAN do this yourself, with the help of the board. i had never done it before either, but asked lots of questions and muddled my way through it. IMHO,anyone who has done as much work as you have already can handle a rebuild. I also think Jim's quick and dirty fix is worth considering, especially since you don't want to invest much money in the car right now. of course, you won't know until you pull the head, but now you know how to do that. BTW: I miss the old forum, but just discovered that this one works very nicely on a PDA. the regular one doesn't, at keast not on mine. Hi JimS, It is good to hear from you and thanks for the note. Well I will at least pull the head to take a look, if there is any other tricks or little things I should know or take car of before, during or after please drop me a note. I will provide photos of my travels down this path. I miss our old forum also but I know things are in the works to make things even better that before.....stay tuned. Andrew
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blue
Junior Member
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Post by blue on Sept 18, 2008 13:37:17 GMT -5
Andrew, while Jim's fix is considered "quick and dirty", keep in mind there is really nothing wrong with what he is proposing. It is a very sound approach to the problem. The negative part is it addresses only the main issue, but that is why it is cheap. Other things in the engine that might be considered worn are left as is. It probably leaves one cylinder in better condition than the other three and you should figure they will need attention in a few thousand miles.
But hey, it is cheap and will keep you on the road for a couple of years!
To give you some perspective on that type of automotive repair, I have an old Motors Manual that describes grinding crank journals with the engine still in the car. The secret of it all seems to be obsessive cleanliness, but Jim has already covered that.
Bill
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Post by andrew on Sept 19, 2008 6:45:23 GMT -5
Andrew, while Jim's fix is considered "quick and dirty", keep in mind there is really nothing wrong with what he is proposing. It is a very sound approach to the problem. Bill Hi Bill, Thank you for the note. I hope to pull the head this weekend an take a look at things. Would it be wrong to install new pistons and rings to every cylinder and refresh the head/valve seats? I can only assume if new lower bearing are installed the cam should then be redone. There comes a point where when you have it all apart......you should do it now??? I really have no idea what a full rebuild would cost $500.00 -$800.00 - $1500.00? I will see if I can find one good used piston and button her back up. I would then be able to drive it a distance to a Sunbeam God. Thanks for the help guys. Oh, I am still looking for photos from Jim, Bill, etc. Regards, Andrew
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blue
Junior Member
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Post by blue on Sept 19, 2008 9:41:42 GMT -5
Andrew, I have not rebuilt a 1725, but I'd expect to spend at least $2500 US, probably a little more for a complete redo with chebby rods and custom pistons. That would be for parts and machine shop, you assemble. That's a big Ouch! to me. It would be bad enough if it was for a car you must have, a real downer when it is for a hobby.
When you start looking at other things to fix, you start down the slippery slope. I'd pull the head and pan, replace the bad things you see as economically as possible (don't look too hard), button it up and drive it while saving money like mad. If you can reuse the connecting rod, I'd put the old rod bearing back in. Don't "fix" anything that is good enough. If you have good oil pressure and the rod is not noisy, it is good enough. The idea is to just keep it on the road for say, 5,000 miles. Money spent on that kind of stuff would be wasted. When the engine is finally rebuilt, you'd probably put in new anyway.
Bill
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Post by Jim E on Sept 19, 2008 10:00:43 GMT -5
Scope creap coming.....
If you are going to patch it keep it simple. The one hole fix lessens the number of things you have to deal, less things to go wrong. No point in replacing all the pistons for this patch, the bores are still going to be worn and with 150 pounds compression in the other bores you could just make it all worse tinkering with the other bores. Plus you got three times as much debris from the honing. Three more rod bearings to worry about, three more sets of rings to seal... three more pistons to clean the ring lands... you get the picture.
Provided you have decent oil pressure and the head is ok you can pull the one hole patch off and get maybe 5k miles out of it heck maybe a lot more. With all parts and tools in hand this is an easy weekend job to put you back driving. Not to mention it will hone skills for a full on rebuild. Plus you can then find another motor start buying parts for a build over time, thinking about what you want and not be parked.
For a full on rebuild you can expect to spend $2500 or easy more depends on what you do. Then there is the time issue the last Alpine motor I built took a month and a half or so due to parts issues and machine shop wait time. You send stuff out and just have to wait for it to get back, then if you forget to order a part you wait or you get the wrong part. Still that was a fast build time.
Oh a full build I advise you build the motor on paper before you buy anything. make a list of all the parts and cost, figure out who will do the machine work and how much it cost. Shop around for parts and go visit machine shops ask about cost and turn around time.
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Post by lgurley on Sept 19, 2008 19:14:18 GMT -5
A friend of mine once pulled the head, replaced a broken valve stem.broken piston and broken rings on the side of the road where it broke. This car was a '56 Chevy 265 automatic and the year was 1965. I rode in and drove the car many times after that and it still ran good in 1969 when he traded it in. Some times fixin what's broke is the best thing to do.
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Post by philipk on Sept 19, 2008 22:04:56 GMT -5
just saw this eng. trans combo for $275 1/2 hr before I saw your post this may help if its bad sfbay.craigslist.org/scz/pts/845689465.html hope you dont need it . if you can do one cyl. thats fine I agree with Jim . if your not racing its not like it will matter. I had a back yard vw eng rebuild with a diffrent piston in cyl three ran it for three years and 25000 miles never a problem and it was the best vw I ever had
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Post by andrew on Sept 22, 2008 7:05:48 GMT -5
It was great to receive this information and I appreciate your comments and views. I was unable to get the time to work on the car this weekend so I will start on it this week. I will price the tools today that may be need for the rebuild (hone/ring compressor etc.). As soon as I have some photos I will post them to my web site and provide the link, I would love to know what you think as I have no idea what to expect.
Now I am about to ask a few questions that may sound silly but.... What allowance should be provided between the cylinder and the piston? I have no idea what tolerances should be considered or even how to size rings etc.
I will try and round up a good used piston and purchase rings for it but I have no idea what modifications the past owner has done to the car.
Thanks guys, Andrew
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blue
Junior Member
Posts: 51
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Post by blue on Sept 22, 2008 8:30:53 GMT -5
Andrew, down here, the auto supply chain stores will lend most of the stuff you will need, check them out first. But in the meantime, make haste slowly. Remove the head and assess the situation, especially the cylinder wall. It should be smooth and shiney, with no deep scratches. Compare it to the other three. Measure the cylinder bore just under the ridge. It might be a good idea to stop and report back as it is possible the damage is too extensive for this type of repair. If things look good, remove the piston and measure the cylinder at the bottom. This will be the size piston you need. No need to get involved with clearances on this type of project.
Good luck
Bill
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Post by andrew on Sept 22, 2008 9:51:11 GMT -5
Sounds good Bill, thanks. I will report back soon with photos and more information about the car. Regards, Andrew
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Post by Jim E on Sept 22, 2008 10:20:11 GMT -5
Oh Bill, Bill, Bill we don't need no stinkin measurments..... Andrew forget all that measuring crap and do not buy anything until you open the engine. Once you know the head is reasonable as in no sunk exhaust valves and the water jackets are not ate up you will be fine. Provided there is not a hole in the cylinder wall or the piston is not busted. But this is not going to be the case or the thing would not have got you home. Measuring is just going to make you nervous because it is not going to be in spec and you have to put the same size piston back in as you take out. So just scrape the carbon off the top of the piston and see what size it is. Then put out the word for a used piston. Heck you may not need a piston, once you get it out you can see how much slop there is in the ring land and go from there. If you do need a piston you put the new used piston on the rod that is in the engine. There are going to be scrapes on the cylinder wall if the rings are busted just the way it is and nothing you can do about it. Just hone it clean it and button it up.
You got a couple things to worry about.... the head, and oil pressure oh and the ridge at the top of the bore. The ridge can be a problem when it comes to getting the piston out but most likely will not be an issue the time it is a problem is getting the piston back in with out damage to the new rings.
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