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Started by ScotY, Wednesday, May 27, 2009, 09:30 AM
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Is there any way I could convince you to do a semi-detailed writeup on the steps involved? Nothing too detailed, but a general step-by-step, special tools required, tricks to avoid having to buy special tools, things to watch for, how to identify possible problems, etc.? Thanks, Scot
Honest;y. if it's a good running quiet no-smoke engine, why would you want to rebuild it at all?While it is out, I would put in a new timing belt, tensioner, water pump, oil pump and new seals. other than that, why rebuild somethign that doesn't need it. In my opinion unless you know absolutely what you are doing, or trust the machine shop 150% rebuilds can sometimes be a crap shoot. Take a check around the board and see how many fully done "rebuilds" ended up having issue after the fact.To be 100% honest I would check everything over really well (including the crank key way), and unless it leaked oil somewhere I'd run it. I'm the kind of person who likes to do things right, so if I started on a rebuild, it would become a full blown project and ended costing a lot of time and money.As long as nothing is obviously out of whack install and have some fun before the summers gone.FWIW I pulled the valve cover off of a used engine I picked up to replace the seal. I found that the rocker arms still had felt tipped marks on them the head was brand new start to finish. Like I said shoot- it still had the cylinder numbers felt tipped on the rockers. So at the very least look it over before tear down and make sure it hasn't already been rebuiltHTH--Sky
I wouldn't know where to tell you start man. I'd hate to tell you to do this, or don't do that and then you get it back together and the dang thing doesn't perform like it should. If I had a good running engine with awesome compression, I would atleast plastigauge the bearings and install new ones accordingly, replace every seal on the engine including all gaskets (except head and intake), do the waterpump and timing belt (don't forget the thermostat), completely wash the engine and make it nice and shiny again to help you find any leaks that may occur over time and check valve clearances. This is more of a prep and should not be considered any type of rebuild. If you decide you need new rings (your compression is low), you're first going to have to measure the cylinder for being out of round. If that looks good you would then need to check each piston to make sure that they are not worn past service limits and check the wrist pins for wear. If both are good, then you are good to go with rings. You would need to get a ridge reamer and take off the ridge at the top of the cylinder to keep from destroying your new rings. You then want to hone the cylinder to a very smooth, fine finish with a nice cross hatch in it. You should be ready to check the crank and rods now. For this you will need plastigauge, a torque wrench and a dial indicator. First thing I would do would be to measure for excessive crank travel indicating bad thrust bearings. This is the measurement the crank has front to back as in trying to come forward out of the block or backward into the transmission. If this is not in specs, you will need new thrust bearings to control this movement. Careful attention should be made to the block and caps when and if you decide the bearings need to be replaced to make sure they aren't damaged. Most of the time you will be OK on this. If that is good, move onto the main bearings and rod bearings in that order. Pull the main caps one at a time and look for uneven wear or pits, gouges, or anything out of the ordinary. If you have a problem with the crank at this time, you will need to deal with that accordingly; maybe a simple trip to the machine shop to have the crank turned and dressed will suffice. If it doesn't, then you will need to replace it and start over with the entire shooting match. Assuming that the crank is in good shape, you will now be ready to measure each main bearing for clearance with plastigauge (which just happens to be one of the coolest tools/aids ever been invented). This will tell you the condition of the bearings matting surface to the crank. If they are all within spec, you will be good to go and leave them be. Now you do the same as above for the rod bearings.This is when I would order up a new oil pump and strainer (unless you see that the strainer is perfectly clean) as the block and crank are all in good shape and money can be spent. I almost forgot a very important step that should be performed if the head is off. Before you get too carried away ordering this and that and building the bottom end, you will need to borrow a machinists straight edge and check the deck for being warped. While this isn't all that common, it still happens and will flat out ruin a head or cause a headgasket failure if it is not promptly addressed.Move on to the head now and check it like you did the block for being warped. You may have to have it machined as most will need it. Pull the rocker shafts and arms and remove the cam and valve springs making note as to where each and every peice came from (which cylinder they belong to). Pull the valves and look for uneven seating and burnt places and check the stems for being scratched or worn. You want to check the guides with a bore indicator as well to make sure that they are not in need of replacing. If the guides and valves are in good shape, I would still recommend having a shop to do a 3 angle grind on them and I would port and polish if I had the money as it frees up HP that will make a difference. Clean everything up very well and install new valve stem seals and put everything back together and set the valves. The head should be good to go. Lots of time and work go into building an engine properly and the more time and better attention to detail you exhaust on this, will depend on how well this engine performs for you and to what amount of service you will receive from her. I'm sure that someone will chime in and mention something that I forgot or add their own little tid bit that they do but this will/should get you going in the right direction of where to go with yours. Just remember, you can check compression and do a cylinder leak down test on an engine that is not in the vehicle. It's a little tricky if you don't have a tranny that you can bolt it up to, to be able to use the starter to spin it over with, but a leak down test is better, IMHO, than simply a compression check. Lots can be learned from doing a leak down test and you can find problems that you didn't know you had and it will point them out to you as in what area, valves, rings, headgasket and so on. Too much typing for me in one post. Hope this helped ya out a little.
I rebuilt my 16v and enjoyed it.
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