altezzaclub

OK, you just change the 4K stroke in the maths to your 3K stroke. So the cylinder volume is smaller, but the head gasket volume & the combustion chamber area stays the same. I would expect the combustion chamber volume to be about 27ml, I think that is what Richard got for his 3K head on the 345K we built. However, his 3K head had the whole combustion chamber sunk into the head a mm or so, giving a circular ridge all the way around where the head gasket sits. Maybe someone else on here can explain that. I reckon 0.75mm off will give you 10.0 to 1 but you can check that using your cyl volume of 291ml and chamber of 27ml. You can measure the Mikuni's diameter with calipers. They'll be somewhere between 36 and 40mm I expect. See the one slide that is not sitting equal with the others? Make sure they all move up and down in synchrony. Best thing is, search the net for everything you can, or find a mechanic locally who knows about them, and strip them down & clean them. Check the diaphrams and gaskets for leaks, the jets for dirt and see what can be lubricated.. The size of the carb exit into the manifold will tell you the manifold tube size to use, and that should match up with your inlet ports on the head. I'm sure they will work on your K motor, they just won't get fully exercised! You will need some curved manifold tube to allow for the sloping K motor, you want to end up with the Mikuni fuel bowl horizontal. Grab a mixture display meter if you come across one, I found it invaluable in setting up the twin SUs. They use needles like your Mikunis, so you can sand the needles to change their shape in different rev ranges. If you get one, have a nut for an oxy sensor welded into your extractors before you fit them. The option is a dyno for air/fuel mixture readings, but that might take quite a few runs and get expensive.

loL- cheapest fun you can have! I remember Steve's dad watching the paddock bashers saying "ruining my pasture those boys, ruining my pasture..." You can see why they use Cibies in rallying.

Ah, so the cams were already weakened. This must make for some real fun at traffic lights...

ooohh...nice workshop! 27ml is less than I expect, unless its a 3K head (or one of the 5K variants). The sheet of plastic makes it much more accurate as it fill up evenly to the hole you make in it. My 4K had 31cc and the graph paper added up to 30sqcm. So for me- Head volume 31ml Gasket volume = Pi X radius X radius X thickness= 3.14x3.95x3.95x0.15= 7.35ml Cylinder volume = 322ml compression ratio 322+31+7.35 to 31+7.35 which is 9.4 to 1. Skim 1mm off, you will remove (chamber area X 0.1)ml whch is 30Sqcmx0.1=3ml Now you have 322+(31-3)+7.35 to (31-3)+7.35 which is 9.86 to 1. So you can see how you use the head area from the graph paper to calculate how much to skim off to give you any compression ratio. If you really have 27ml in the chamber your figures would be 322+27+7.35 to 27+7.35, which is 10.4 to 1, before you skim it! The valves could do with a spin in the drill with sandpaper to clean all the carbon off the back of them. Keep the seats nice and cleanly cut like you have them. Think of how small the gap is between the back of the valve and the edge of the valve seat, and all your airflow has to go through that few mm. So anything to make the back of the valve smooth and polished helps. That is why they cut valve seats in three or more angles, to maximise that flow through the narrowest gap. If you look at a cam graph you realise that most airflow goes through a much smaller gap than at max lift, as the valve is only at max lift for a millisecond. Its why unshrouding the valve area by cutting back the combustion chamber wall also helps, if you look at an inlet in the head you see most of the airflow area has a wall right in front of it. Changing that is the major advantage of 4valve heads. Here's some random reading I found loking for a diagram- http://www.s26261265...drews/heads.htm You can see how the area close around the valve does not flow as cleanly as the open side. The combustion chamber wall blocks it, and then the cylinder wall is too close. Its a black art! In the '70s Ford found some of their heads straight off the production line flowed better than highly modified ones they had spents hours porting.

The next time you break the diff, don't weld the gears together, fill in the gaps between two teeth. That will give it a little open diff movement (about 1/4turn) and give better turn in. Put the stock springs back in, its far too low for dirt & you'll just smash the udeneath to bits. Look at the springs for marks of them being coil-bound, and check the bump stops for marks of them being hit. You want the car to just not quite coil bind and just touch the bump stops on the worst bumps. We tossed out the stock bump stops and got softer more progressive ones. Once it hits the stops or coil binds the stress goes on the sidewalls and the tyres instantly lose grip. Read "How not to build a rally car" to see how bad it can get. Same problem with the shocks, you end up pulling the car down into the dirt all the time unless you can find front shocks the go down stiffly and go up faster. Corona LCAs for more front camber... So much fun, so simple and cheap!

Plastic sheet between 1mm and 3mm thick is easy to find, it just has to be big anough to cover one cyl. drill a 5mm hole through it & seal it with grease around the edge. 25ml graduated burette or pipette is best to measure the liquid, use kero or turps or similar. Each combustion chamber will take around 30cc,so you run in 25cc the refil the burette for the rest. Burettes have a tap on the bottom, so are expensive. A 25cc graduated pipette will also do, you release drops by turning it with your finger over the top. Use the porting tool to unshroud around the valves, especially the inlets, taking them out to within a mm of the head gasket mark. Make them all the volume of the largest unless you get keen and just make them all as big as is needed to give the valve breathing room. Then skim the head to get the compression back up. You calculate the amount to skim off by measuring the area with graph paper, then working out what size "column" to take off to get the ratio you want. Everythin else like cylinder volume and head gasket volume is known and fixed. Post up here if you want a lecture on it...

I will take a look next time I'm down there.

Also- put a straightedge along the manifold faces where they touch the head. If they're not lined up well, try to loosen the 4 bolts holding them together, using lots of "bolt-loosening oil". Don't try too much torque or they will snap, but I have had some come loose and some stay frozen. If you can bolt the manifold up with them slightly loose the two manifolds will align correctly, then you do up the four bolts. If they are not straight on the head you get the well-known exhaust gasket failure in the middle. Best idea is to buy extractors and throw the cast ones out, although they usually need some alignment work too!

Don't worry about the water, just dry it out with a rag. Its just spillage from inside the head as you lifted it. If you're not taking the pistons out you can turn the motor by hand and wipe the cylinders a few times, then put a bit of oil on the walls. You're right, no valve stem seal on that one. Exhausts don't need them as they are under pressure when the valve is open, the inlets are under slight suction so they tend to suck oil down the stem and into the cylinder. I can't see which that one was. That valve looks good, just needs a cleanup. The thickness of the ridge around the bottom shows it still has plenty of life left. You can send it off to a head shop or do it yourself. You just spin the valve in a drill mounted in a vice and hold sandpaper against the dirty bits. Start off with about #100 grit and then use about #240 wet & dry paper with a spray of WD40 or CRC 556 or whatever light penetrating oil. That will bring the metal up clean and shiny, but don't sand the seating surface or the shiny stem. Then you grind the valves in with hand-grinding tool and some fine paste, just like they did for the first 75years of automobile engines. The ports get a cleanup with a flapper wheel on a drill, it just cleans the carbon out and maybe tidies up the casting marks. If I were you I would buy a porting tool ( a cutting burr for alloy) and grind the ports out to match the one-piece gasket sold for K motors first. Just let that diameter blend back into the normal throat size further in. It will match the aftermarket inlet manifolds for carbs like Webers and SUs and probably help inlet flow on the stock carb.

more phots needed! The bottom photo looks like a timing chain bit, but the top one makes no sense. So, its a rivet holding three strips of metal together/ Heavy knocking suggests crankshaft system part- bearings, piston, conrods. Not too much advance giving knocking and a worn bearing from it? Well, how far apart have you got the motor now? Anything else odd?

That's some serious gear! Its worth getting another shell to keep using it all.

Should've looked behind when reversing... I think the score is 1 each, neither pole nor car is usable! Shame... All that work down the drain. Any parts worth selling back into the club?

The starting problem sounds like the solenoid, although it would pay to pull the wire off and measure 12V getting there every time you turn the key. At least then you know you have voltage, even if you might not be getting enough amps. Probably the contacts inside the solenoid are worn away. In the past I have either reversed the contact bar inside so it is woring on a new surface, or put washers under the contacts to move them closer to the bar, just depends on the solenoid manufacture.. The misfire being worse with headlights on suggests that not enough current is arriving at the coil. Try hotwiring the coil straight off the battery and see if the misfire vanishes. Did you check the earth leads from the motor to the chassis and the chassis to the battery negative carefully like Tor said? The 11volts is actually higher than I expected if you have a ballast resistor in there, so the voltage is fine. That's assuming the Bosch coil is the "R" version, made for working with a resistor... Certainly this suggests the alty is not up to its job and there is not enough power being produced- Are the altys using external regulators? If you changed altys either both were poor of the voltage regulator is not working correctly. I figure a 2" exhaust is larger than a 4K needs, I'd expect it to kill some low-down performance. It might all change with a single DCOE Weber fitted...

they will get your block and head far cleaner than you ever can. However it will all have to be stripped to bits for them, so that would mean piston out and new rings. If this is so then bearings and head work should be right. When you have it back together and running you can sort carbs. What inlet manifolds can you get? Weber DCOE, single or twin? SU carbs, single or twin? Can you have an inlet made up for something? Twin DCOEs seem the most common, but if you can't buy a manifold then you could make one for amything. Bike carbs on a 2T...

I don't think you could skim a head enough for pistons to hit the plugs. What you really should do is fit all four plugs and make sure they protrude into the combustion chamber the same amount. Use shim spacers to get them even. Then do your combustion chamber sizing to get all four chambers the same volume using those plugs, so you have 11:1 on all four cyl. Parrot's right, you should try a heat range colder. If it fails when cold or at low revs you can always go back up..

So, if it looks like it, why do you think it is not? By now you'll have the timing chain cover off and know either way. Maybe those bits were from an earlier incident and have been replaced. What sort of knocking was it? Did it happen all the time, when cold and hot, low revs and high revs, under load and no-oad, at idle??

Go for it! Just put it back on and tighten it up to the right torque. You can just look at them for wear and scouring, or you can get some Plastigauge and measure the clearance. Inspect the welch plugs and if they show rust rip them out. Clean out the waterways as much as possible with compressed air &/or a water jet. Look for oil leaks at the front and rear crank seals, timing chain covers etc and replace any leaking ones. Fresh oil would mean a leak, old dry oil may mean its not worth worrying about. Check clutch & release bearing. Check the manifolds for any leaking marks and repace if needed. Make sure all the bolts/nuts screw freely to tne end of their threads. Wiggle water pump bearing, look for leak marks. Take out thermostat and measure opening in a pot of boiling water and a thermometer. Check cam lobes and followers for wear. So far all you've taken off is the sump. Do a leakdown test with a compressor feeding air in via a spark plug hole and both valves shut. If each cylinder holds pressure OK, assume the valve are good. If air pressure leaks away and you can hear it in the inlet or exhaust manifold, then its head off time. Grind the valves, skim the head and inspect the bores. How big is the lip where the pistons stop, or borrow bore calipers and measure the bore. With the head off you have a better chance of cleaning rust and scale out of the water jackets. Check the carbs for wear in the shafts and signs of old abuse. not much else I can think of.. I'm sure there's more that other guys can come up with.

Tall motors, aren't they....

Ah- good point, you will have a steering box or something in the way. Those cams were just the ones I considered, and I only wanted a 270deg cam. I bought the Crow for its fast lift before 50thou lift is more important at 2500ft than at sea level. I can take a look for hotter cams on those websites.

I'll believe you- I've never got a handle on these things with leaf springs.

..and the next obvious question.. Straight airmail is $40 for 500g-1Kg, and registered mail is $46. http://auspost.com.au/apps/international-parcel.html?searchCriteria.countryCode=NO What are extractors worth over there?? About $220 here, but they are a very bulky shape to mail.. Maybe we could sea-mail those and let it take a few months. Hurricanes are the only ones now I think, not equal-length or anything flash, but better than stock! I paid $215 a couple of years back. https://www.bestmufflers.com/bshop/product_info.php?cPath=552_554_801&products_id=3763&osCsid=57ae04612c40c21b6546910ecbcb4efb

I can get you one cut and mail it over. $150 would do the cut. You should get the followers cut afresh so they wear to the new cam, and I'm sure we have cams and followers up in Woolshed Rallying. Cam cut and followers came to under $200 for mine at Crow, I think it was $170 all up including mailing it back to me. Have a look through the cam specs at Crow, Tighe, Camtech, Waggott, Wade & Camshaft Engineering. I think Crow and Tighe do most of Rollaclub's cams, but they will all have cams in similar ranges. I picked a miild cam for high altitude, a 270deg, the Crow 606. You could easily run a 280-285deg since you're not in traffic... The stock springs work up to 0.4" lift, although guys on here have gone higher. After that you need new springs. Visit www.performancetrends.com and d'load cam analyser3.2 and have a play. These are the mild cams I researched a few years back, I didn't list the hotter cams from each company-

I don't know how they can use it on the road! California must be a hot-rodders dream country... Love the exhaust idea!

Head off! Those compressions are weak, either valves or rings (or both) need doing. The variation between them suggests valves over rings. The head is the easy part, so just as you say, strip and inspect, look at the bores and piston slap, grind the valves, port the head, skim it and fix all the bolt holes. Make sure every bolt (incl head bolts) go right to the end of the holes. Take a bolt of the right thread and cut a slot down it with a hacksaw if you don't have the right tap. There is a picture in The Girls KE70 build. That will allow the dirt to go somewhere as you screw it in and out. A compressor is nice too. With clean boltholes, put a touch of grease on every bolt when you fit them. I would re-use a head gasket that has not been run, I've had to do it with some assembly mistake or paranoia in the past. But any gasket that has been driven on will destroy itself coming off. Clean the waterways out in the block while the head is off too. If you took 10thou off the head you woldn't worry. 15thou means you'd have to use 95octane or better. You'd just alter the timing if it 'pinked' from extra compression, but the japanese versions ran more than the exports. A hot cam will handle more compression better than a stock cam, pre-ignition happens more at low revs witha stock cam as they fill the cylinder more. So skim it now in readiness for a hot cam later. option two- Pull the motor out and do the same, but now its easy to clean everything and fit a ground cam. You could do bearings without pulling the pistons out and lighten the flywheel, all good ideas but the cost creeps up and up. Aim for a single DCOE and extractors later, as you can do those with the motor in place. Doing the cam and flywheel now means you don't have to pull the motor out again later. Someone on here could mail over a gasket set if they are hard to get there. Same with a ground cam.

Ok, learn about tuning it- You should have the tappet gaps correct, or can check them after a month. Points gap correct, and if you change it or they wear it affects timing too. Plugs gaps checked. Timing with a timing light preferably, 8-10deg before TDC although they will run well with a little more advance. Set the carb mixture for best idle and then set the idle speed. Stacks on Youtube about how to do those jobs, or ask on here, and you'll be set! My blue car always runs at 1/3 up the temp gauge, my gold car a tad higher just under the halfway mark. I use a bit of garden hose, about 1.5M long, and a plastic funnel to do g'box and diff oil. Prop the funnel up against the car and feed the hose into the filler hole, then pour g'box oil in slowly. You can buy filler bottles, some you squeeze the oil up a curved steel spout, and flash ones that you pump the oil along a hose.