ellooo. i have a full railway depot workshop at my disposal, so I'm once again trying to fix the 1.6 arc/avy hybrid...

so I've stripped it all down this time.

the car only did 30 miles since doing the head gasket and rebuilding the head. so new stem seals, valves relapped, new headgasket and new headbolts.

this was the state of it beforehand

and here is after. all valves kept in same order btw.

now while the head was off i did a leakage test on the cylinders with 10/40 oil and they didnt go down for days. so i assumed they were alright.

built it back up and timed it all, turned it over with the ht leads disconnected to circulate the oil and straight away there was fresh oil ontop of cylinder 1&3. WTF?? musta been from the head as the sump still had the old dirty oil in and you could clearly see it was clean and fresh (i poured some on the head before i turned it over)

so i did a 30 mile trip to the garage it was in for winter, and in that journey it burned a whopping 1 litre of oil. LOL

compression tests were good at 240,220,220,225 PSI.

now I've finally took the engine to work and stripped it down.

poured parafin (very thin) down the bores, and they didnt leak off for quite som time, indicating a good seal on the rings..

and then i carried out the same test on the head.

and this is 10 mins later!!

so i thought fuck it. ill take the whole lot apart and rebuild it all. best way for an apprentice to learn about engines eh? well thats my excuse...

bottom end

crank

workbench....

and a 1.6 litre AVY piston compared to a 64 litre maybach train piston for the sheer hell of it..

hahaha..

the oil in the bottom end smelled nasty. like it was burned or some shit. also had a maaaasive crack in the sump lol.

to be continued!!

Edited 6 April, 201313 yr by erixtar1992

I see that the most important tool features well in your pics. (The tea cup, that is!!)

You seem to have made an excellent job of cleaning the carbon from round the tops of the cylinders and from the piston crowns! It is possible that this 'super cleaning' may account for at least some of the the high oil consumption, as I notice that the bores seem to have a shine (glaze?) on them. In combination, this could be the cause.

The first picture of the valve, looks very much as if it is from an engine which has been standing for some time, is there any tell-tale rust marks part way down any of the cylinders?

The contact area on the valve seats looks to be rather wide. - Valve contact area is always something of a compromise, too little contact and exhaust valves tend to overheat, as the only time that they are cooled is when the valve is seated (apart from heat loss through the stems to the guides). Too wide a contact area and the sealing pressure from the springs is shared out over a greater area, resulting in less contact pressure.

You almost certainly have facilities for re-cutting/grinding those valve seats within your workshop, so I would be very tempted to do a three angle cut/grind, which will not only reduce the contact area, but will also improve gas flow.

If you are putting the same pistons back in, I would also lightly hone the cylinder bores and fit new piston rings.

Also, make sure that you have got all of that oil/paraffin out of the head bolt holes before re-building. - Hydraulic pressure (caused by tightening the bolts into oil filled holes) has been known to split castings. - The same thing, of course, goes for the main bearing bolts.

Regards.

All very good points made by David there!

I know you're going to rebuild with rings, definitely hone it. And have your crank journals polished too if you're changing shells.

You could try some crack detection spray on your head - or have it pressure tested.

Your good compression results could also partly be down to oil in the cylinders effectively raising the CR, but also improving the seal on the piston rings.

Often if you suspect piston rings as being the cause of low compression, a drop of oil down the bores will improve your reading slightly, so you having oil everywhere may improve your results in that aspect.

Your head test with paraffin will test the seal of your valves in their seats.

I would get your head pressure tested, potentially new guides & recut the seats.

Measure your bores too for wear, just because the honing marks are visible doesn't mean it won't need honing.

That, and you'll be mega fucking happy when it's finished.

Oh, my, God.

It's such a better engine than the 1.4!

video of it with both cams a tooth out, fuelling out, ignition timing not set and burning a shit load of oil.

https://www.facebook.com/photo.php?v=460455...e=3&theater

ha

I see that the most important tool features well in your pics. (The tea cup, that is!!)

You seem to have made an excellent job of cleaning the carbon from round the tops of the cylinders and from the piston crowns! It is possible that this 'super cleaning' may account for at least some of the the high oil consumption, as I notice that the bores seem to have a shine (glaze?) on them. In combination, this could be the cause.

The first picture of the valve, looks very much as if it is from an engine which has been standing for some time, is there any tell-tale rust marks part way down any of the cylinders?

The contact area on the valve seats looks to be rather wide. - Valve contact area is always something of a compromise, too little contact and exhaust valves tend to overheat, as the only time that they are cooled is when the valve is seated (apart from heat loss through the stems to the guides). Too wide a contact area and the sealing pressure from the springs is shared out over a greater area, resulting in less contact pressure.

You almost certainly have facilities for re-cutting/grinding those valve seats within your workshop, so I would be very tempted to do a three angle cut/grind, which will not only reduce the contact area, but will also improve gas flow.

If you are putting the same pistons back in, I would also lightly hone the cylinder bores and fit new piston rings.

Also, make sure that you have got all of that oil/paraffin out of the head bolt holes before re-building. - Hydraulic pressure (caused by tightening the bolts into oil filled holes) has been known to split castings. - The same thing, of course, goes for the main bearing bolts.

Regards.

hi david! the tea is deffinately the most important part!

the tops of the pistons were actually super clean the first time i took the head off, which may be slightly worrying. the car was running very very rich for a couple weeks while i had some jets on order.

the pistons will be getting a fresh set of rings, and the block will be getting honed. i will most likely buy a honing tool and do it on the pillar drill.

the engine was standing for a little while yeah. nothing major though. and there are no rust marks or anything suspicious.

unfortunately i dont know anything about grinding valve seats, and as we dont have any milling/CNC machines i doubt i could do it. i will most likely just obtain another known working head from somewhere and rebuild that, as the cost for new valve guides, remachined seats and new valves will be monsterous.

makes perfect sence what your saying about the contact area though!

thanks for the heads up on the parafin ect. i am going to use the pillar drill and drill + tap the headbolts out to M11 to use the proper AFH headbolts, so that shouldnt be an issue.

cheers!

yeah nick. most likely that the excess oil was causing the descent compression tbh.

I'm just gonna get another head i think. not worth the cost of all the machining work really.

i willmeasure the bores. any idea what values i should be looking for? or just checking that there still round ha. with telescopic guages i presume?

IMO you'd be better off paying someone to hone the block, probably cost less than the tool and its not just a case of banging it down the bore mate.

hmm. ill look it up online how its done ect, aswell as getting my mentors opinion

Measure the bores top, middle & bottom to make sure there round and not oval, then if within the limits, the honing tool in a pillar drill, plenty of lubricating oil and keep the tool moving up and down so you don't do more in one area, as all your doing with the honing stones is removing any glazing on the bores so the new rings can bed in correctly, if there are any big steps at the top of the bore then you might need a machine shop to do an overbore.

Honing tools are £25 from Machine mart for a proper one and its not too hard to do on a pillar drill look it up and just be careful when doing it

Measure the bores top, middle & bottom to make sure there round and not oval, then if within the limits, the honing tool in a pillar drill, plenty of lubricating oil and keep the tool moving up and down so you don't do more in one area, as all your doing with the honing stones is removing any glazing on the bores so the new rings can bed in correctly, if there are any big steps at the top of the bore then you might need a machine shop to do an overbore.

Also has to be done at the correct feed, to gain the right cross hatch angle depending on the type of oil scraper ring your using.

cost me 30 inc vat to get mine honed and washed lol

The tool was 23 quid of ebay ..

Rather pay tbf :)

Yeah max has already said what I was gonna add. You have to get the right cross hatching pattern, which IIRC some manufacturers vary the angles of the cross hatchings.

IMO some things it's easier to pay to do, unless you've been trained/properly shown by someone in the know. It's like lots of people don't bother having their frank journals polished before fitting new bearings shells, I thought this was just part of rebuilding an engine - standard procedure if you like.

Seems silly to me to spend money on rebuilding an engine to be fresh and last, but taking short cuts which may reduce its life anyway?

I had the following work done:

Block/head/pistons/rods/crank hot washed

Head skimmed

Valve seats recut to 3 angle

Valves recut

Head skimmed

Block honed

Crank/pistons/rods balanced

Flywheel lightened and balanced

Clutch balanced

Think I paid £200 IIRC which is probably cheaper than the going rate - but we're still tasks I couldn't have accurately carried out myself tbh.

Hot wash i can do myself,

No point messing with this head, just pissing in the wind really as the guides arent great

dont need stuff balanced

only honing really. Which I'm fairly confident i could do.

Well see.

Was just giving you an example that people get in their head engine work costs thousands, I trust my own abilities and have a honing tool but still didn't fancy doing it lol.

Yeah lol, I'm not going as all out as you did tbh. Just replacing what i need to really. Id like to have it done for summer time if possible.

Going to build up the bottom end first, so at a minimum i need rings and a hone. Think i may get away with the shells. It all looks fairly neat and tidy in there. As i said though i will get my mentor to cast an eye over it as hes very experienced with this sort of stuff. His level of knowledge is actually rediculous. Ha

If there is a decent engineering shop handy, it could pay to get your existing head sorted by them, you never know when you buy SH if it is any better than the one you took off.

Also, if your existing valves are in decent condition, they would be able to re-face these for you, which would make a better job than ever you could with just grinding paste. With re-cut seats and re-faced valves, all that you would need to do would be to give them a light lapping in with fine grinding paste.

You don't need a milling machine, CNC or otherwise to cut valve seats, but the cost of cutters or grinding machine would be prohibitive for a one-off job.

It is important, if you are replacing the valve guides, that the new ones are fitted BEFORE the seats are re-cut,as the cutter is centered in the valve guide.

As already said, it is important that the correct feed rate is used with the hone, as it affects the cross-hatch pattern. Also do make sure that it gets a good hot wash afterwards, otherwise you will be leaving the abrasive inside the engine.

Do check that both the block face and the cylinder head face are flat before assembly.

Hope it all goes well.

think I've found the issue. well, a couple actually!

whilst looking over the pistons ect, completely ignored the oil scraper rings! didnt even think to check them.

had a look earlier and there fucked! took one out of piston #1 (the one burning the most oil) and put it in the bore, it clearly is gonna do bugger all as it almost falls down under its own weight!!!

so new piston rings time, and i will hone it on the pillar drill most likely. shame as the compression rings are completely fine upon inspection.

my other problem is the valves and guides. they have been lapped in waaay too much, and as a result the contact area between the two is WAY too big. think the seats and valves are sposed to have about half a degree difference? can someone confirm?

used some engineers blue on the valves and rotated them on the seats ect, you can clearly see the surface area is too large, aswell as the fact they arent seating fully all the way around.

so i am going to regrind the valve seats with a tool at work, and also will be regrinding the valves on a lathe. worst comes to worst I've lost nothing.

rechecked valve guides today, there sloppy, but none of them are 0.8mm (which is the max apparently), think the worst is 0.6mm.

so in short:

• new piston rings and oil scraping rings
• hone the block on pillar drill
• regrind valves on lathe (got the tooling)
• regrind valve seats to correct angle (need to know specs)
• rebuild bottom end with current bearings/shells as all very good condition
• possibly drill and tap block to fit M11 headbolts
• skim head
• port matched inlet manifold

Edited 10 April, 201313 yr by erixtar1992

please drill and tap the block properly don't use a pillar drill do it on a proper milling machine and makesure you clock each hole up there isn't a lot of play for misalignment at all

Yeah something like 0.5 deg difference on valve/seat angle.

Should have less than 1mm contact area IIRC, just a nice thin line with blue/will show in the lapping paste at that stage.

And FYI, a friend of mine into old old hotrods fucks around at the drag strip and has ran one of his engines without oil control rings before and still didn't really burn much oil, like yours is on another scale - id still get the head pressure tested.

yeah mine are MUCH more than a mm haha will upload a pic if i have one.

yeahh but thats a different engine man maybe it dont affect that one as much? idk. its burning oil on all 4 cylinders its just that 1&3 are far worse than the other two lol

You can have 1/2° difference in the valve and seat angles to make a narrow seating and/or you can dress the stone for grinding the seatings to 60° then 30° and finally 45° for the area which the valve will seat on.

Obviously dealing with all of the seats at one angle before re-dressing the stone to another angle, or you won't have any stone left by the time you get to the last ones!!!

Regards.

Id recommend you take your absaloute time with this one, make sure you follow every step carefully and thoroughly, theres no rush. Id certainly get the block done profesionally though. As pete says, doing it on a pillar drill isnt ideal, it needs to be clocked and dimensioned properly. Honing is better to be left out, than done incorrectly by a novice,

Shells can be inspected too, a blade ended micrometer is the best bet, is that something you can get hold of? Or are you planning on just getting new ones?