Building a hot vintage engine with Jonny69

[Jonny69]

I guess you aren't going to go for a funky vernier sprocket to time your new cam in..

I always mark a tooth on the crank sprocket and the adjacent tooth on the cam sprocket , that way you don't have to rely on setting engine at TDC to get it accurate. Do it with a center punch and it won't rub off either.

My new one is stock timing but that's a good idea. There are timing marks on mine but I couldn't decide what way up they went

Sorry Jonny for the little OT, but are vernier sprockets worthit if I decide to change the cam in mine?

Depends on the cam. If it's a fast road jobbie then don't bother, it's so much easier to just use the standard wheel and it's accurate enough. If you have a race cam then it might have different timing to the stock cam. If optimum horsepower is at stake then use a vernier but most cams are ground on a stock dowel anyway and modern grinding tolerances are so good you'll probably find it's so close it wasn't worth the expense and time spent timing it in

You really won't notice if it's a degree or two out, there are so many other things that will affect it like spark gap, timing, fuelling etc. I ran my Kent 244 in my crossflow (which is quite a wild grind) on the stock dowel and it was almost spot on. I don't think I'd have got much more out of it.

 

[Jonny69]

Jumped straight in at the deep end this afternoon and got on with the relieving around the bores. Popped the headgasket in place and secured with a couple of head studs:

This is so I can mark around the edges so I know where to grind and where not to as the chamber in the head is reasonably tight around the area:

Scratched my marks in with the tip of a chisel and removed the gasket and I was left with this on each of the bores:

Took the bulk of the meat off with a grinding disc on the angle grinder which made pretty light work of it and was left with this lovely rough edge to clean up with a half-round hand file:

 

[Jonny69]

Which left me with this lovely smoothed run into the bore rather than a sharp step. I gave it a quick lick over with some 400-grit wet and dry just to take the file marks out and all was done:

It's a bit difficult to see in the photos but it's about 5mm down from its original position and will let the piston suck in quite bit more as the sidevalve design is quite flawed. Then I gave it a good old wire brush, a clean down with Gunk followed by water, washing up liquid and a rinse, same with the sump which was lined with slime.

Went against my normal rules and fired on a coat or two of fire engine red, won't get much time tomorrow but I will be able to sneak in a few extra coats of paint

 

[Jonny69]

Looks good mate, are you going to take out the ports aswell for better flow, surley even if you just give them a polish it will make a god bit of difference? If i were you i would grind the conrods aswell, grind the casting flash off, on most rods you can also take a fair whack off the cap. Then a polish and ballenced end to end is a process which you could do yourself with an accurate set of scales.

Not going to be opening the ports up at all because the valves are quite small and it won't be of any benefit. No point having a large flow area squeezing into a small area. The main pinch point is across the tops of the valve guides so I am going to machine them down if I can hold them tight enough in the chuck. I have already run a file down the ports and knocked the flashing off.

Trouble with grinding down the rods is they are already very spindly and as you said it'll throw the balance out. I have no accurate way of balancing it myself and I've driven a badly balanced engine and it wasn't fun!. Effort to realistic power gain, not worth it on this engine unless I was overboring it.

 

[Jonny69]

OcUK killed my bandwidth

 

[Jonny69]

Sooooooo my bandwidth got caned so all the old images are dead until the 28th :

No worries because I can make like a gypsy and move in on someone else's land as such. Yeah I'm stealing some webspace temporarily...

So here's what I've been up to. Got on the lathe on Tuesday night courtesy of a particularly generous bloke I know and turned down all the valve guides. Had to swap on the 4-jaw chuck to get a hold on them because they are in two halves but after a bit of setting up progress was good and I'm happy with the results.

Before, after and, er whoops:

Broke one of them so I'll have to pilfer one out the spare engine. Cast iron I think and it's like machining something between glass and china. I'll cut the remaining one by hand since it's not critical how square they are, I just want them recessed out the way.

 

[Jonny69]

I also got my head back. Nice bit of work, bit expensive but NOOOOOOOO! he's taken too much out the chambers! Ah well I guess I didn't explain it to him properly. I asked him to cut the base of the chamber down flush and I think he took it a bit too literally and cut right into the slope in the end of the chamber:

The bit between the two dark areas is supposed to be a nice smooth curve but now it's a deep step. Well I ummed and arrrrred about it quite a lot today but I think the only real solution is to add some metal back on. This is what the head looks like though, nice skim:

So this metal-on mod. This is going to involve welding to cast iron which is brittle. I decided the best way to do this is to get the head hot and weld it hot so the concentrated heat buildup isn't as high as if the head were cold. This will reduce warpage and reduce the likely hood of it craking. So the SWMBO is out tonight which is a piece of luck because I'm banned from bringing car parts in the flat let so please no-one let her know I've been sticking them in the oven.

225 degrees for 30 minutes until smoking nicely, which it did and the flat smells like it's been on fire. Severely. In the meantime I stuck the thick wire in the MIG and ran a couple of test beads on a spare head. When I was happy with the results I ran up and grabbed the one out the oven, ran down with it in my welding gloves (choking on the smoke and yeah it was bloody hot!) and zapped in a couple of runs of weld to fill the gap:

 

[Jonny69]

This is what I was left with after a quick wire brush. Once the head cooled down I thought I might un-shroud the sparkplug a bit. It sits right in the thread and is practically covered so I reckoned a good healthy chamfer would come in handy, get that flame front moving a bit quicker like:

Then while I was working on the ports in the block I gave the head a few licks of paint, red again:

Followed this with a rather nice shish kebab, chips and a few glasses of wine while I watched California Kid

 

[Jonny69]

you should not use coolant when turning cast iron ( unless its the very high tech stuff £20 gall ) as it work hardens when the coolent chills it , it then gets that hard it will not cut, CI that has been uses as a bearing also becomes work hardened on the surface due to the oil .

Funny your should mention that because when I finished someone said don't use coolant and I noticed hard spots but assumed it was sand in the casting. Had to make teeny tiny cuts in the end or it didn't go through

I'll see how it goes with the head, it seems to have gotten away with it. I plan to lap it onto the block with some grinding paste anyway and if there are any high or low spots that should show them up.

 

[Jonny69]

Thought about it but it's not a point where it has to flow well and I've knocked the tops off them with a stone. If it's an issue I'll do it or get another head on the go as it's not as if they are expensive. I don't actually have a die grinder so jobs like that are quite difficult.

In hindsight what I would have done is begun the weld in the middle of the vee and worked outwards in one continuous weld (rather than 3 runs) so the high spot appears in the middle rather than off on one side. But it's difficult to see exactly what you're doing without stopping and taking a look with the naked eye. Like I said it's not a flow point so it probably won't make any difference.

 

[Jonny69]

Well the final box of goodies just landed on my desk. Some adjustable lifters, timing chain, head studs, valve springs and an engine mount. I shall ignore how much that cost

 

[Jonny69]

While ignoring it, how much do replacement parts cost for a car/engine this kind of age? I'm guessing most will new pattern parts rather than salvaged originals? Is there much done in the way of modernising materials/designs for these kind of parts?

General day to day stuff is quite cheap. Some parts can be surprisingly expensive because none of it is interchangeable with later engines like all the Kent crossflow kit is, so yeah it's all new pattern stuff. But then things like the gaskets etc even for crossflows are starting to get expensive because the demand is dropping off. Tuning goodies cost what they cost and it's pretty much the same across the board and the Aquaplane inlet and exhaust were quite a lot but then a twin DCOE manifold and decent tubular exhaust for a Pinto or Crossflow would cost roughly the same new. The only thing is I normally get all that stuff cheap second hand but it's just not around any more for an engine this old.

 

[Jonny69]

Didn't get round to doing much this weekend but had second thoughts about the welds in the head. Took my comically underpowered cheapo fake Dremel to the welds and cleaned them up. Got through loads of wheels, grinding stones, a miniature burr and managed to destroy both the cheap brass collets and the arbors that the grinding wheels mount on. Never mind, it made a good job of them and here's my mate Chris lending a hand:

Little did he know he'd later end up in hospital with a chunk of this in his eye. It had gone rusty so they had to dig out not only the chunk of metal but a piece of his eye where the rust had set in

So there's my safety tip for today folks, when you do this make sure you squint...

 

[Jonny69]

Grim. I hate eye stuff Hope it all goes well.

Bravo on your sig effort there Batf1nk. I remember finding that thread the next morning

 

[Jonny69]

I had my specs on

 

[Jonny69]

Last night I got in the ports with the cut down valve guide and boy does it make a difference. With the stock pointy ones the port is really blocked up but with the cut down jobbies you can stick your finger in the port and out the valve hole!

Meanwhile continuing my kitchen theme I took some pictures of the goodies that turned up before the weekend. Here on the microwave we have the valve springs:

The one on the left is the uprated one, it's about 3/4" longer than the original and a lot stiffer. This is good because it'll put a lot more preload on the valve when it's shut and prevent any blowby with the increased flow and compression. This was a problem even in standard form because I could turn some of the valves on their seats with the end of my thumb. This said to me they weren't very tightly closed.

They came in the most awesome dog eared box pictured here on the chopping board next to the courgette:

Finally, and apparently hovering over the dishwasher is one of the adjustable tappets next to an original solid one. They were expensive but when you see the amount of work in them you do have to wonder how they did them at that price:

They will adjust right out so can accomodate the extra lift on the cam and will make doing the clearances much easier than grinding the valve stems or seats.

These will be the last lot of pictures until I get back off holiday unfortunately but the aim is to get it back in and running ready for the Nats. Will probably use the standard intake and exhaust manifolds at first then upgrade to the Aquaplane bits when I have time to fettle the linkages and rebuild the carbs. Clock is ticking...

 

[Jonny69]

I wouldn't have thought to check that, cheers for the heads up

 

[Jonny69]

Hopefully I'll get it back in the car within a week of getting back. Just got to lap the valves in, turn down another pair of valve guides and re-assemble.

The guides say that the Aquaplane gear is good for +10% per manifold so minimum I'll gain is 6hp. Ultimately it'll be more because of the other work I've done and there isn't much worse than the standard intake and exhaust design

 

[Jonny69]

Valve grinding was tonights job. It's been a while since I last did this and I remember it was one of those jobs to put off because of the blisters and bruised hands that follow. Anyway enough of my complaining and on with the build...

My local spares shop had this old timey tub of valve grinding paste sitting on their shelf for what looked like about 50 years. I bought it over a decade ago and it sits on my shelf becoming history awaiting my next engine build. You use so little of it I doubt I will ever get through it!

You get coarse paste at one end and fine at the other. To apply it you need a stick with a sucker on the end which you can get for about 50p from any good spares shop or alternatively Halfords does one which comes with two little tubs of grinding paste for £2.99:

The paste is like grease with grit in it:

And you apply it with a mucky finger:

 

[Jonny69]

You do this with the springs off so the valves are free to move. Apply some coarse paste to the valve seat and stick the sucker to the top of the valve:

Then twizzle the stick back and forth between your palms, lift the valve out, turn it round a bit, repeat and so on until you've taken the valve and seat back to clean metal and there is no pitting:

Then repeat with the fine paste which takes the surface down to a smooth finish and clean it all off thoroughly:

Mine were particularly bad so this took me about 2 hours all in, plus the valve guides drop out so I had to put all the valve springs in to hold them in. I did a simple test to see if it had worked. I pressed down on the valve lightly with my thumb, puckered up and blew into the port as hard as I could. No leaks!

Today my hands are bruised to hell but surprisingly no blisters