Building a hot vintage engine with Jonny69
- Thread starter Jonny69
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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 wentDogbreath said: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.
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 insaitrix said:
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.
I'd say it worth using a dial gauge to set just to check. They are usualy pretty close but sometimes they can be a few degrees or more out. If this is the case you can often use offset keys or downels to adjust the timing (as I did on my xflow) rather than splashing out on a verner pulley/sprocket.
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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:
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:
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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
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
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Soldato
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Jonny69 said:
That just screams high performance, you can feel the magic from here
LOL loving the work, must be fun doing something so far out of the norm!![[huzeeee]](/styles/overclockers/avatars/3.png){kind=avatar}
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.
Sorry perfectionist, but you should remove the rough casting with a flapper wheel or summit.
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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.[huzeeee] said:
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.
Ohh fair enough, i did all the rods for my mini myself, manages to get a good 10 or 20g of metal off each rod (the rods differed in weight massivley from standard) and as you know with old engines, Every little counts when it comes to gaining power. If i were to make annother engine for my mini i would go the whole hog on porting, valves, guides and matching the head to the manifold because it work which you can do yourself, costs minimal and gives substantial power gains.
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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.
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.
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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:
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:
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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
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
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good nights work mate 
and a quality film to boot
and a quality film to boot