Building Chevy 4.3 liter V6 - 1994 with balance shaft
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I'll use this article to describe, report and evolve on this project to have one single place where to reference to in the various forums I'm a member. Please refrain from simply editing, instead leave your comments and ideas in the discussion section so I can correct my text and integrate your input (with reference to your contribution) to keep the text neat and clean and "from one casting". Thanks | I'll use this article to describe, report and evolve on this project to have one single place where to reference to in the various forums I'm a member. Please refrain from simply editing, instead leave your comments and ideas in the discussion section so I can correct my text and integrate your input (with reference to your contribution) to keep the text neat and clean and "from one casting". Thanks | ||
| − | + | A bit of a warning and a statement about liability. I am not a trained mechanic. All advice given is to the best of my knowledge and I will normally point out where I'm not sure of my actions or cannot back it up with experience or advice from others. I will not be liable for anything be it information given herein nor advice or procedures I describe or use. It will be ALL AT YOUR OWN RISK. | |
| + | STORY - NICE TO KNOW (skip if you want) | ||
| + | Having said this you may want to know why you may continue reading the stuff a guy writes up which is not even a mechanic. A bit about my career. At age 14 I started my first build on a 50 cc PIAGGIO CIAO moped. After the first year at age 15 I had to realize that most of the stuff you hear from your friends about tuning and power increases are "legends" without proper research. So I started to read books from the library about 2-stroke engines, then about the tuning of such engines. From the scrap yard I got two more of these moped engines and a friend sold me a moped for 50 bucks, because he had cut a big hole into the frame to accommodate an exotic carburetor but which had weakened the frame and it started to flex. Had it welded nicely at my workplace at the time and got it all painted in black. The moped does still exist today at my fathers place and still runs. | ||
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| + | I'm a business administrator with a bachelors degree and a professional pilot. All my life I had unique opportunities to work with great mechanics. I helped them, learnt and had access to professional garages for my leisure to tune and do servicing on my rides, be it cars or motorbikes. I used to work for technical companies all my life and was involved in sales, tech specs, IT, drawing (yes making bluepints), construction, all learnt on 20 years on the job. In this time I worked with motorbike specialists on MOTO GUZZI and DUCATI owning first a MOTO GUZZI LE MANS IV and later a DUCATI 900 SS. Then with a friend had over 6 ALFA ROMEOS between Alfa Sud 1.3 litre boxer engine, Alfetta GTV (which in the U.S. went by "Alfetta GT veloce") Alfa 6. Then worked on my own FIAT UNO Turbo i.e. 1.3 litre turbocharged. Had to solve quite some things on all the cars we ran with. | ||
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| + | During the same time I could work with a specialist on Alfa Romeo. I spent a day or two with him every month and worked on all kinds of cars. Learnt about carburators (DELL'ORTO, WEBER, SOLEX), about engines, rear axles, ignition, steering, setting up a car and tuning. Done some special work and wrote a guide on the famous Alfa Romeo Montreal SPICA mechanical injection. Took engines apart, gear-boxes, rear ends and got dirty on some very rusty stuff. It became a hobby with an increasing level of proficiency. | ||
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| + | Since nearly three years I work part-time in a garage specialized in the restoration of Italian old-timers. Except of gearbox and engine final assembly I'm charged with my own projects and can again work with great mechanics. My own project which will be my journeyman's piece is an Alfa Romeo Alfetta GTV 2.0. My engine building piece will be this 4.3l V6 CHEVY because my Blazer starts to act up on me with more than 200'000 miles on the odo. So I'm confident that most of the text I write is correct, if not I stand corrected and I'm always willing to learn from informed people. | ||
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| + | Actual project status and outlook chronological order bottom to top (newest on top): | ||
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| + | ... | ||
| + | Machine | ||
| + | Decide what to do to the block and heads | ||
| + | Remove all casting stuff, sharp edges etc. | ||
| + | Crack checking the block, heads, crank | ||
| + | Take all parts to the machine shop to hot-tank | ||
| + | Disassemble all pistons, rods | ||
| + | Disassemble the heads | ||
| + | Remove lifters cam, balance-shaft, plugs and all from block | ||
| + | Build engine stand | ||
| + | 2016-JAN-22: Engine tear-down nearly complete. Moved all the stuff to my place. | ||
2016-JAN-21: Engine tear-down done. The crank and the rotating assembly has to go tomorrow. | 2016-JAN-21: Engine tear-down done. The crank and the rotating assembly has to go tomorrow. | ||
2015-DEC-28: Loose brainstorming - trying to formulate what I want it to become. | 2015-DEC-28: Loose brainstorming - trying to formulate what I want it to become. | ||
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- cc the ports | - cc the ports | ||
- measure, note, measure, note... | - measure, note, measure, note... | ||
| + | - remove all burrs, sharp edges, make it look nice outside (casting) and inside | ||
| + | - Port matching | ||
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The next step is storing in cardboard boxes for transport. At my place in due time I will pick a couple of bags and start rebuilding stuff or make a list of what to order. During the process I have kinda three piles of stuff: Fine to be re-used / Rebuild or order / Trash. Once nearing completion I want an inventory of only Fine to be re-used and Trash as that means I have all parts ready for final assembly. | The next step is storing in cardboard boxes for transport. At my place in due time I will pick a couple of bags and start rebuilding stuff or make a list of what to order. During the process I have kinda three piles of stuff: Fine to be re-used / Rebuild or order / Trash. Once nearing completion I want an inventory of only Fine to be re-used and Trash as that means I have all parts ready for final assembly. | ||
| − | TBI | + | |
| + | '''TBI''' | ||
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Next is the TBI, carefully remove all plugs and sensors. It's easier to remove them as long as the TBI is still attached to the intake manifold. Then remove the 3 bolts of which 2 are special ones and detach the TBI body from the manifold. | Next is the TBI, carefully remove all plugs and sensors. It's easier to remove them as long as the TBI is still attached to the intake manifold. Then remove the 3 bolts of which 2 are special ones and detach the TBI body from the manifold. | ||
| − | MANIFOLD | + | '''MANIFOLD''' |
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Loosen all bolts from the intake manifold and detach the remaining supports for various stuff, pre-clean and label. Then remove all the intake manifold bolts. A couple of light taps at the corners were enough to crack it loose despite the block having rusted quite a bit. All sheet-metal supports have rusted, some even rusted away completely. Remove the manifold, pre-clean and store. (Will be checked, cleaned, ported and finally painted in the process.) | Loosen all bolts from the intake manifold and detach the remaining supports for various stuff, pre-clean and label. Then remove all the intake manifold bolts. A couple of light taps at the corners were enough to crack it loose despite the block having rusted quite a bit. All sheet-metal supports have rusted, some even rusted away completely. Remove the manifold, pre-clean and store. (Will be checked, cleaned, ported and finally painted in the process.) | ||
| − | STUFF ON THE BLOCK | + | '''STUFF ON THE BLOCK''' |
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Then I got rid of the engine mounts, lateral sensors of the block on the accessible side. Depending on how you disassemble you may also remove the other sides stuff such as the other mount, oil level dipstick and such. | Then I got rid of the engine mounts, lateral sensors of the block on the accessible side. Depending on how you disassemble you may also remove the other sides stuff such as the other mount, oil level dipstick and such. | ||
| − | HEADS | + | '''HEADS''' |
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The 1994 engine has solid plastic covers with three retainer bolts. These are very special bolts, apart from that no surprises. As they have a rubber seal they crack loose when hit with the flat hand on one side. Now we have access to all the rockers. To just pull the heads (I will tear them down later at my place - for now it is just to get handy pieces) No need to remove all the stuff such as rockers, retainers, valves... | The 1994 engine has solid plastic covers with three retainer bolts. These are very special bolts, apart from that no surprises. As they have a rubber seal they crack loose when hit with the flat hand on one side. Now we have access to all the rockers. To just pull the heads (I will tear them down later at my place - for now it is just to get handy pieces) No need to remove all the stuff such as rockers, retainers, valves... | ||
I have switched to an air tool (as I have access to it) but it would be possible by hand as well. Loosen all the retainer nuts on the rocker arms. Leave them tightened a couple of threads on the studs so the rockers stay with their respective valves. I would recommend this as well for repairs. No need to take them all off, because when reusing them you have to keep them in the exact location from where they came. They break in to their respective pushrod and valvestem. Once loos you can simple lift them a bit and turn a couple degrees to free the pushrods. | I have switched to an air tool (as I have access to it) but it would be possible by hand as well. Loosen all the retainer nuts on the rocker arms. Leave them tightened a couple of threads on the studs so the rockers stay with their respective valves. I would recommend this as well for repairs. No need to take them all off, because when reusing them you have to keep them in the exact location from where they came. They break in to their respective pushrod and valvestem. Once loos you can simple lift them a bit and turn a couple degrees to free the pushrods. | ||
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And now the other side - same, same. | And now the other side - same, same. | ||
| − | FLEXPLATE | + | '''FLEXPLATE''' |
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Six bolts (air tool again), then wiggle it off or use an appropriate puller. Just make sure, the engine is supported in a way, that the flex plate is not bearing any load of the block. | Six bolts (air tool again), then wiggle it off or use an appropriate puller. Just make sure, the engine is supported in a way, that the flex plate is not bearing any load of the block. | ||
| − | OIL PAN | + | '''OIL PAN''' |
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The oil pan has four larger bolts in the corners, three special studs(bolts) on one side and a couple normal bolts for the rest. Two metal inlays serve as washers on the full length of the oil pan. In order to remove them I had to unbolt and remove the attachment for the remote oil filter hose from the oil pump outlet outside of the block. (This is a 4x4 version VIN Z engine). Tap it with your flat hand it should break loose quite easily. When removing pull it up slowly and gently. It will get stuck on the oil pump pick up which is nested through the slush guards inside the oil pan. It will need a bit of gentle movement fore and aft to clear the pick-up screen. And now we're at the crankcase. | The oil pan has four larger bolts in the corners, three special studs(bolts) on one side and a couple normal bolts for the rest. Two metal inlays serve as washers on the full length of the oil pan. In order to remove them I had to unbolt and remove the attachment for the remote oil filter hose from the oil pump outlet outside of the block. (This is a 4x4 version VIN Z engine). Tap it with your flat hand it should break loose quite easily. When removing pull it up slowly and gently. It will get stuck on the oil pump pick up which is nested through the slush guards inside the oil pan. It will need a bit of gentle movement fore and aft to clear the pick-up screen. And now we're at the crankcase. | ||
| − | CRANK AND CRANKCASE STUFF | + | '''CRANK AND CRANKCASE STUFF''' |
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The first thing to note is that the 1994 VIN Z engine has two bold mains. That means the main caps have only two bolts a piece. The next oddity I noted is with the numbering of mains and the rods. The mains have an arrow pointing forward and all different casting numbers but no specific locator or identification. So I will see where to add one with my machine shop. The next thing was the rods as I found the letters F-F, J-J, G-G stamped on them. Seems they are paired. Will see tomorrow what the logic is. As I want to keep them exactly in location I will number them as well to keep the sets properly together. | The first thing to note is that the 1994 VIN Z engine has two bold mains. That means the main caps have only two bolts a piece. The next oddity I noted is with the numbering of mains and the rods. The mains have an arrow pointing forward and all different casting numbers but no specific locator or identification. So I will see where to add one with my machine shop. The next thing was the rods as I found the letters F-F, J-J, G-G stamped on them. Seems they are paired. Will see tomorrow what the logic is. As I want to keep them exactly in location I will number them as well to keep the sets properly together. | ||
| − | ''' | + | == 2016-JAN-22 - TEARDOWN, THE REST == |
| + | After all the stuff has gone from the block I'm left with the rotating assemblies. Crank, rods, pistons, camshaft and balance shaft. I had to take the engine apart for transportation reasons. Needs to go up and down a steep ramp (next to a stair) so I'm not going to pull a 300 lbs engine into my place. | ||
| + | To have it even more handy I'll now take the rods, pistons and the crank out of the block. | ||
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| + | '''OIL PUMP''' | ||
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| + | Now I removed the oil pump to get it out of the way. one center bolt is connecting it to the block. Carefully pull it out straight as the shaft is some 20 cm long (8 inches). Place it in a pan or your old oil drain as it may still contain some engine oil. | ||
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| + | '''MARKING''' | ||
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| + | Got 6 nice sized clear plastic boxes and some more boxes with separators and a lid from IKEA to store all the stuff which will come out and not mix it up. | ||
| + | Marking will be done with the EDDING water resistant pencil on a cleaned and degreased surface (brake cleaner on a rag). | ||
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| + | As the block is upside down I first figured correct location of the cylinders. Left is odd, right is even. Number one is in front left also where the cam drive sits. Then wrote the cylinder numbers down on the freeze plugs which were the only places without rust or oil. | ||
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| + | I've used the harmonics damper loosely put on the crank snout to turn the engine over. If it does not turn easily by hand you're in for a heavy rebuild anyway. Mine turned just fine with a bit of resistance but could be turned with one hand. Place the rod you want to split into a convenient location where you can set the wrench and break the nuts loose without hitting your hands on the sharp edges of the crank. I normally write a little legend on the workbench (aluminium sheetmetal cover) for the nuts position and the rest. As I do not know at this point what I will do to the engine and don't go into the hassle of remembering all the stuff that has to be marked with position and direction of assembly I simply mark everything. | ||
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| + | A rag with cleaner I search for a convenient spot to mark the rods, wipe the oil and dirt off and mark it with the cylinder number. I also mark the forward position with an arrow and a 1 and 2 for the bolts and nuts. Mark the cap and the rod with matching cylinder numbers. Ever had your cat stray into the garage and push a box with stuff over.? Then try to match parts. In general the rods and crank and stuff are marked by the factory but they tend to use funny ways. My rods are marked F-F or J-J but then I found that three where marked F-F. So I'm not going to take chances on that. | ||
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| + | '''ROD AND PISTON REMOVAL''' | ||
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| + | Loosen the rod bolts but leave them on at least a couple of threads. Gently tap one of the two bolts with a plastic hammer. The rod should split right away. Because the bolts are still in place it will not fall into the depths of the crankcase, cylinder bores. Now remove the nuts carefully. Hold the rod part with one hand and with the other wiggle a bit on the rod's cap. They should come out easily with a slight pull. Sometimes residual oil will cause a bit of suction/adhesion on the bearing surface. Try to pull it straight or it may bend between the two bolts. Original bolts are kind of forced into the rod and will not fall out. Aftermarket may fall out, one of the reasons I at least hold the upper (long) portion of the rod where I can get my hand in to avoid it slide down or the bolts to fall out. If they do - use a magnetic pole or flex handle to pick it up. Do this anytime something falls down. Search as long as it takes to find and remove it. If you turn the engine for the next cylinder you can nick the cam or crank or a bearing surface with the bolt somewhere in the depths of the engine. Lay the parts aside on the legend of the workbench. The lower part of the rod bearing can stay attached to the crank. Leave it there as it is nearly impossible to get it out. It will stick to the crank due to residual oil. Once the piston is out you can easily pick it from the crank. | ||
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| + | The piston rings should have enough resistance that the piston will not fall out. Normally it should take a little push to move it up in the bore. Actually moving down, as the block is upside down now. Push the piston down by pushing on one of the bolts with your thumb, so you can leverage with the remaining fingers on the edge of the block. It will most of the time move down until the compression ring (aka the first ring on the piston from the crown) hits the cylinder wall where the rings do not run. This is in most cases an area some 3 - 4 mm (a little less than 1/4") on top of the cylinder bores. There is no abrasive force so it creates kind of a step a few thousands less in diameter than the cylinder bore where the pistons run. | ||
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| + | Think of how you can center the rod in the bore, tap it with an adequate tool to move down and once it slides out (actually falls out) catch it! Have somebody help you or as was my case with the block upside down on a flat space the piston will just fall 5 cm (2 inches) and lay on the table. Put some cardboard underneath to soften the fall and catch residual oil dripping from the piston and bore. | ||
| + | To get it out the trick is to suspend the rod with one finger from the bolt and position it in the center of the cylinder bore in order for the rod not to touch the lower skirt of the bore and get stuck. The upper portion of the rod bearing is normally still in place in the rod. It is cramped in the bore despite the 4" bore. I use the plastic hammers handle (wood) after making sure that the end is round and has no protrusions from stuff embedded in the wood. Then try to tap slightly on the piston pin bossed or if that is not possible on the rod. Another possibility would be to remove the upper rod bearing and tap it in the rods bearing location. | ||
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| + | '''WARNING!''' | ||
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| + | Light tapping should be well enough to have the piston slide out. If you hit resistance re-check your rod alignment with the bore. When dealing with really old engines with many many miles check the ridge on top of the bore. Check the bores for rust. If all fails it may be necessary to carefully lower the rods and pistons as much as possible and remove the crank first to pull the pistons out of the bores below. You may have to loosen all the bolts, remove the outer ones in order to be able to access all the inner ones with the crank in a horizontal position, then remove all the mains and pull the crank. | ||
| + | Or maybe the best advice is to ask your machine shop or take the block to the shop right away. | ||
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| + | == TIPS AND TRICKS == | ||
Drain the engine oil with engine hot. Or maybe place the engine close to a heat source or at the sun to heat up while draining. Maybe even a couple of days. Especially the water will still pool. By placing the engine at different angles you may drain most of it. Once the heads are off Some coolant may drain when turning the engine over from the passages in the back between block and heads and from the two located between the first and last and the middle cylinders. It is so much easier without the mess of oil and water. | Drain the engine oil with engine hot. Or maybe place the engine close to a heat source or at the sun to heat up while draining. Maybe even a couple of days. Especially the water will still pool. By placing the engine at different angles you may drain most of it. Once the heads are off Some coolant may drain when turning the engine over from the passages in the back between block and heads and from the two located between the first and last and the middle cylinders. It is so much easier without the mess of oil and water. | ||
Spray all bolts with penetration oil and let it soak. Re-spray after 30 minutes and best is to go for lunch. | Spray all bolts with penetration oil and let it soak. Re-spray after 30 minutes and best is to go for lunch. | ||
Spray the gasket edges e.g. TBI, Thermostat, sensors, head-gasket as well. | Spray the gasket edges e.g. TBI, Thermostat, sensors, head-gasket as well. | ||
| + | I nearly always wear surgical gloves when working on dirty stuff. At the same time these gloves save you from fine metal filings which can sting through the skin. Use the "nitrile" ones as latex will dissolve in most of the fluids we have around engines. | ||
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