rebuilder86

Perhaps it would be nice to see 4x oversize 5k pistons sitting upside down on an inverted cylinder head in their rough positions, to see just how small the gaps between them are.

But theres only so much distance between the far side of cylinder one and the far side of cylinder 4. Obviously it works, or we wouldnt be having this discussion haha, but my concerns are about the ability to fit 4 x 83 mm bores inside the dimensions of the 4k head and block. I think its just all incredibly tight on a 5k, based on all the pics on the net.

Not only that, but the part number for the 5kj head is the same part number for the 4ku/j head, confirming it is the same size.

Nah mine has std liners, theres heaps of meat. I think for a std 4k liner the bore is extended form 75 mm out to 77mm, no where near a 5k after 4 succesive rebores at 81.5mm. (80.5 std + 0.25, 0.5, 0.75, 1). So look its not actually the water jackets that concern me, I can't understand how the 5k can be bored out at all and still have enough meat between the cylinders. Just look at a std 5k headgasket, there is litteraly no rubber between each cylinder. I recon itd be like a piece of sheetmetal seperating the cylinders haha

Thats how i found it. Yeh its still I'm the sump haha. No broken pieces anywhere to be seen. Remember everything here is dirt cheap, so its possible its just an aftermarket piece that is so crap it just broke. Kickn, so why are people always saying not to bore out a 4k to 80.5 mm for 5k pistons? Does the 5k block actually have more meat on the cylinder walls along with thinner water jackets or s9mething like that? And if so, how is this possible when there is the limitation between the two middle bores. They are so close together even on a 4k.

anyway so heres that damn chain, i found it. The part number gives me these hits http://www.japan-parts.eu/?parttt=&part=13506-13020&regi=EU&cars=ok

this piston is at TDC. it has about 1 mm worth of bore involved in the equation. Note, you can see the liners clearly here

but thats only true if the combustion chamber isnt the size of the bore, which it is on these motors; the combustion chamber includes some of the bore when the piston is at TDC. The piston stops about a mm before the deck or something like that. So if u expand (bore out) that smaller compression chamber area along with the entire swept volume, you are in fact enlarging one half of the equation, the compressed half, meaning they both cancel each other out, mathematically. That smaller half of the equation, (the little TDC combustion chamber) is more sensitive to change, because it is smaller to begin with, so increasing it marginally, has a significant effect on the entire equation.

Yeh tge compression ratio will remain about the same on this motor, as the piston does not travel all the way to deck height. For compression ratio to increase with a rebore, the piston would have to have always (before and after) reached absolutely 0 clearance between cylinder head and piston crown. This is because, in my case, with the very small clearance between crown and deck, plus the distance between deck and cylinder head (head gasket), every bit the bore gets larger, means a larger "clearance volume" proportional to the increase in swept volume. So unfortunately, i can't gain compression by boring out. In fact i have evidence / proof. The rollaclub wiki page shows blocks and associated cr figures. The 4ke and the 5k both share the same piston types introduced in 1982 just proportionally wider for the 5k with the same increase in dish volume. The 5k has less compression ratio due to its larger clearance volume. 4ke 9.5:1. 5k 9.3:1

Yeh i always thought 5k was just impossible to even rebore or do anything to because its just a 4k block with bores that are bigger and bigger pistons??? No??? Does it really increase the C/R though. I havent thought about it too hard I'm three beers in, but i imagine widening the bore also increases the combustion chamer size at the same ratio of increase in the swept volume.. Or is it because the piston just about nearly touches the head and the entire combustion chamber is only in the head. I'm thinking of d dish pistons. So i guess if its a flat top piston and the piston does almost touch the head then i guess i can see how it would increase the cr enough to make a difference.

and in case anyones thinking of bringing a stuffed oversize bore back to life by inserting a liner to bring it back to standard, it may not work. these are the dimensions of the std liner ID 75mm OD 79mm so the walls are abotu 2mm thick.

apparently sleeving of the 4k is possible because the block is iron, the walls are thick enough to accommodate a sleeve, and they have loose enough tolerances in the first place to guarantee any sort of reasonable life expectancy. This information comes from a foreigner friend i met here, another aussie bloke (older absolute drunk), who also has one of these jeeps but did it up with performance parts with no end to the amount of money spent. So with his information and what ive learned, a sleeve (semi finished liner) is able to simply be pressed in and out of the bore, with a 0.01-0.03mm (for older motors like this) interference fit, which means the liner is about 0.01mm too big. They can just be pressed with hydraulics, but this then requires a machine shop to then bore out the sleeve so that is is 100% perfectly cylindrical then honed, but with a loose tolerance motor like this, it can simply be pressed in while block is hot, and then simply honed quite vigourosly with a good computer controlled hone with even pressures to enlarge the clearance ever so slightly. A new out of the package std liner and a standard piston, when held in my hands, the piston slides down the liner perfectly with little to no play. (i did it in the parts shop) but when the liner has been exposed to the pressures to install it using a hydraulic press, apparently it shrinks a bit so this is why it needs the machining or honing. Saying all this, you can only get away with the easy method of press fit and hone, if the parent bore is 100% perfectly machined and there are no imperfections. Luckily for me, this engine has been around for an eternity, and therefore probably is pretty capable of accepting a hot press and hone type install. With all this in mind, I'm pretty sure a decent rebuilder in a 1st wold country would laugh and say don't be ridiculous, bore the block and put oversized pistons in you idiots. Banjo, the answer to your last question, no. The sleeve is designed for one size. Once its worn out, u press it out, and press in new ones, thats the beauty of it, its a never ending engine block.

Here u can even get oversized ones hey. One thing ive never realy understood is why they call them semi finished. Semi finished apparently means u have to bore it and then hone it. To me thats the wrong term. Semi finished implies to me, that the walls of the liner are in a half finished state, meaning they need to be honed only. my research into these particular liners from federal mogal, reveals that i can get semi finished liners, which need to be pressed in while block is hot (so there is no distortion), then apparently only honed slightly to size.

Google it and the only product ull find is by federal mogul, cheap china shit who pretend to be made in the good old US of A. U have me interested now, i wonder what it takes, to sleevify a non sleevable motor. I know first hand why they do it here, suppliers have to combat the absolute lack of knowledge the automotive professionals have here, for example: Even the very best machine shop with computer controlled cylinder hones, all staff involved believe the purpose of honIng a cylinder is to make it smooth as glass so theres no friction. Therfore, they all; every single machinist, think the honing stones are there to hold the back of the 4000 grit wet n dry while it goes up and down the bore. I shit u not. They wont listen when i ask for it t9 be done propperly. Suppliers know this is the pits of the earth and therefor take advantage of the stupidity, while at the same time ensuring consumers get a cylinder bore that will seat a new set of rings, by making products that can simply be installed and removed, no intellect required.

They do here. This country is all about liners haha. Its insane i know.

trying to find the chain to take a photo, but when something of mine breaks, the locals scourge through the rubbish trying to get the remains of what i throw away, its like treasure to them. i think its gone now. basically, it just looked like a link was missing, and absolutely no sign of damage. One thing that shocked me, is the design of the tensioning system, and how a little piece of plasticy rubber or whatever it is, can push up hard against a fast moving chain, (albeit lubricated) without completely grinding away. there was no sign of wear on it. I can understand and accept the big long chain guides on holdens and fords, but a little piece doing all the work defies explanation in my mind.

nah just an entire link missing and somewhere down in the sump now, so my guess is that one side broke free of its pins , then the pins slipped out along with the other side. The pinched (staked) bits on the pins probably just vibrated themselves to the point of shearing off the staked bits. I think i will definitely get one of those double row chains online for when i do the complete rebuild, which is happening next trip. I intend to take the block to a mob in cebu city to push the cylinder liners out and install new ones (involves heating and i have no oven), new D dish pistons, correct cylinder head, and new pushrods to suit.

....Were the very front two (2) sump bolts, actually bolts, or threaded studs with nuts ? ... haha u expect too much of me, I'm rough... when i undid the sump last, i just left the front 2 on each side off because the threads stripped. I ended up replacing them with smaller stainless bolts with nuts, and that was a bitch to undo.| Right well, I'm now going to check out the tensioner more closely and start the engine, perhaps my lack of oil pressure on startup was the reason no oil was spat out, i still havent put that new anti-syphon oil filter on, waiting for some 10w-60 oil for the now Knackered piston - bore clearance ahahaha. Timing chain was single. CBF trying to find a double. now that i know its completely non intrusive and i know how to change it.

So who can tell me, why when i started the engine with the timing cover off, why did oil not spew out, is there no squirter for the timing chain? Or have i diacovered why it broke in the firat place? Blocked squirter?

So I am back in the jungle, havent got round to sorting out my missmatch of 4ku and flat top 4k engine parts yet.. Yesterday, we drove to a wedding in a farm in the middle of nowhere. The last time i saw the bride and groom, we were driving my inlaws multicab up a steep hill and the timing belt broke. I trust my jeepy's mechanicals because i had always assumed that timing chains are invincible. Either thats horseshite, or these friends of ours are a curse, because as we pulled into their farm, the jeep went silent, and when i tried to start it, it span freely. So after a tricycle and motor ride back to town, i get a new chain for 500 pesos (about 12 dollars) and head back with no idea how to do it or what tools are needed. Ive only ever done timing belts; with big easy access tensioners. So reaching down between the battery, fan blades, coolant hoses, radiator, steering components, laying around in the cow poo infested grass, i learned the process for doing this with the engine in place. 1. Loosen all sump bolts so the sump can hang down about 1 cm at the front. 2. Set cyl 1 to top dead centre and make sure cyl one valves are closed, by making sure dizzy rotor is pointing at cylinder 1 terminal. 3. Undo no 1 spark plug and stuff cylinder with rope or strong wire (i had some cat 5 network cable handy) to lock up engine, and then remove crank pulley bolt with short sharp blows. 4. Remove pulley and timing cover, needs a bit of persuation to break the gasket free. 5. Pull out broken chain. Say goodbye to the broken link which is now safely located in the bottom of the sump :p. 6. Ziptie tensioner to fully compressed position. 7. Visualy confirm through spark plug 1 hole that 1 is at absolute TDC. 8. Remove camshaft gear and align the lug on shaft face to the dot on the block just below the shaft seal. 9. Drop chain in around crank shaft and then wrap around camshaft gear such that when pulles tight upwards, the gear and its lug hole line up with the camshaft lug and is perfectly centred. 10. Install camshaft gear bolt 11. Cut ziptie and remove with pliers. 12. Before complete reassembly, put spark plyus back, turn engine over by hand to check no interference, then start engine and confirm it works. 13. Happy dance. 14. Put timing cover back on, from underneath engine making sure to get the round part of the sump seal to sit in the groove properly, then tighten sump back up. 15. Reassemble and rinse off cow poo from arms, back, and neck. It was a mission but relitively simple and straight forward, and i believe if it was designed by any other car manufacturer, it would have been impossible.

when u are revving it, the manifold advance changes very little, unless there is load on the engine; then the vaccum and therfore the advance diaphragm dies off. what happens to the timing mark if u leave the engine at idle, and unplug the hose from the diaphragm? (whille immediately capping the hose with ur finger so u don't get a massive vacuum leak). Sayign that the centrifugal weights should be advancing. SO the onyl scenario in my mind that can possibly cause a retard on revving, is if the weights are sezied, and the manifold vacuum is dropping off as u stab the throttle. any other gentle revving the manifold vacuumm really doesnt change enough to effect the advance diaphragm.

graeme i think shes trying to get u to buy her a new carr!!!! :P If not, and she really had a temperemental no crank situation, the only thing I can think of is when u removed the negative battery terminal to install the accuspark, that u may have introduced a situation I have experienced a few times; the negative battery terminal doesnt conduct electricity when asked to suply a large current, but only sometimes when cold. For me I found it to be from constant connecting and disconnecting of the negative terminal, which seems to kind of encourage that white lead corrosion, at first i thought it was in the usual place, where the terminal clamps around the battery lug, but then i learned it was the copper wires in the terminal crimp which just sometimes don't want to supply any current at all, even to the solenoid.

Oh thats excelent mate. So stoked it was that simple.

read this about the 4AC carb http://members.toast.net/ahines/Carbie_notes.htm

yep definitely need to clean out the idle circuit one thing u can attempt, is to undo the idle mixtrue screw,, and spray carb cleaner through that wiht as much pressure as possible. that may push the particles back out the jet into the float bowl, but its likely itl jstu end up back in there. Take the top of the carby off, find the slow jet which is visible top down, this diagram is drawn as if the 2 sides of the carb are cut in half and pivoted around the centre, for clarity. If u take the top off the carb, the idle jet is visible and is orientated as shown in the diagram. Up down. wheras all other jets (except the power jet in the middle of the float bowl) are sideways. The idle fule, must pass through the primary main jet before it is alowed to pass up through the idle jet, where it is then mixed with idle bleed air. there is also a secondary slow jet, and this wil be on the same side of the carb as the secondary barrel. don't worry abotu that one so much. To get the slow jet ut, undo it with a screwdriver, then stick a pin down the centre of it and try to angle the pin so it grabs onto the wals of the jet and pull it up. When its out, spray everythign with carby cleaner adn blow ackwards through the jet to clear it out.