Building a hot vintage engine with Jonny69

[Jonny69]

Note: Some images are missing because bandwidth on my has been exceeded. I am currently moving images about...

About a month ago the engine in my old Pop expired. It was kind of expected because it had stood for about 15-20 years before I had it and I just put some petrol in it, cranked it over and it ran. Well it was getting slowly worse, lots of noise from the top end and it was weeping a bit of water. Then I took it on a long run on the motorway and the obviously very perished rear seal gave up and I was losing oil out the back.

The decision was taken to convert it to a later lump, out of a car called a 100E because it's a fairly easy swap onto the original gearbox and it's free extra horsepower for the same displacement, 1172cc. Plus I had one that was overbored, cammed, flowed and breathed on and it was going to liven the car up quite a lot. Given a bit of time I realised I really haven't got enough time to do it when my Anglia needs some time so a quick change of plan and I decided to work the original lump. It would all need a rebuild anyway so it's not much more to slip in a cam, do a bit of flow work and get the head ground down for some more compression.

So I'll be needing some vintage speed equipment. Aquaplane inlet manifold, check:

Aquaplane exhaust manifold, check:

Twin carbs, check:

A trolley full of junk parts, check:

 

[Jonny69]

And now I need to do much head scratching because everybody who knows anything about these engines is now dead so I'm pretty much on my own!

Saturday afternoon me and a mate hoiked the old engine out the car. Literally took the radiator out, took the grill shell off the front of the car and lugged it out with a tow rope and a chunky luggage strap. This is the offending item:

I have a spare engine I picked up for £30 that I'm using as a test bed. I was hoping it might be a runner but it has had water in it and the valve guides are shot but it's a good block to experiment on:

That's half a shopping trolley it's sat in, they make great engine trolleys. Please note: Sainsburys charge £1 for their trolleys but they are free at Waitrose. I stole mine from Sainsburys because I feel by not charging me Waitrose has trusted me not to steal their trolleys. I will honour that trust. Sainsburys on the other hand has made me feel like a petty theif so I honoured that too and nicked their trolley. And very nice it is too.

Here's my hot 100E engine. Head off and I'm going to be taking the cam out as it's the same fit for both engines. This one is a re-ground high lift item. Note how the valves are next to the bores, it's called a sidevalve engine and most vintage engines are this design:

First on the priorities is to increase the compression. These old engines have super low compression so they can run on ultra low grade petrol. The Pop engine is 6:1 and the later 100E engine is 7:1, both are too low really and it can be increased by machining the head down. With the extra lift of the cam I need to be sure that the valve isn't going to come into contact with the head if I start machining the face, because it's going to decrease the height of the chamber:

I've measured it in the 100E block and it comes to 9.5mm, direct lift from the cam so it will be the same in the other engine. Next because the inside of the chamber is rounded at the top I need to know I have enough clearance at the sides of the valves when they are open:

 

[Jonny69]

Here's checking the standard lift, I measured to be 7.35mm so my reground cam is quite bumpy in comparison:

I discovered something interesting. Earlier engines were only 950cc and had a smaller combustion chamber to suit the lower displacement. The stud pattern on the head is the same throughout the range so an easy way to get some more compression I figured is to use an early head on a later engine. Also I'd have to take some 4mm off the metal which is going to make it very thin and probably prone to cracking. The early head would only need about 1mm maximum thus leaving me plenty of metal left.

Here you can easily see the difference, it's about 1/3 smaller which will instantly take it up from 6:1 to around 7.5:1 I worked out. Early head is on the left, later one is on the right:

It's a lot more shallow so I have to check I will have enough clearance once the face is ground. It comes in somewhere between 10mm and 9.5mm so it's going to be close once the headgasket is on.:

I'd also better check it's the same width in case the valves don't fit in across. All ok, the valves are 58mm across and the chamber is over 61mm:

 

[Jonny69]

On the chamber on the right hand side where I've cleaned it up you can see there is a bulge either side of the spark plug hole. I am going to get this machined down so that it is flush. That way I can take a bit more meat off the face of the head and hopefully get it up to about 8:1 compression which is plenty for a sidevalve:

Ooh I'd better quickly check it actually fits on the studs, phew that's a bit of luck!

So here's a shot straight down on the bore on my spare engine. I'm going to be doing some flow work here to improve the efficiency. There's a sharp edge on the side of the bore and the plan is to round that off in the area under the combustion chamber. This is an old well proven trick from years gone past and I am going to follow that advice. Gas flows over a smooth curve easier than it does a sharp edge, it's quite simple:

So it's too much for me now, I need to see a mockup...

 

[Jonny69]

And finally I decided to get the head off the engine I'm going to be using. This is a matter of clubhammering the hell out of it, driving wedges in the side, wriggleing and more hammering. It gets well rusted onto those studs. Here I've numbered the valves so they all go back in their correct holes. I'll be regrinding them but it helps if they go back where they came from:

So tomorrow I'll be talking to my mate who is going to grind the head and a week later I should be able to fit it. This week with a bit of luck I'll be cleaning it up, flowing it and screwing it back together.

 

[Jonny69]

Is it a VTEC? Turbo'd?

What? Who? It doesn't even have a water pump or an oil filter

 

[Jonny69]

Spare me your scientific mumbo jumbo, I can't be bothered with all that modern trickery

 

[Jonny69]

Interesting that inlet and exhaust valves are the same size on the Ford, wonder if that was purely to make the valves cheaper to produce?

They aren't quite, the inlet is a tiny bit bigger than the exhaust but my mobile doesn't take very good pictures, probably because it's a telephone not a camera. You can get oversize inlets but because they are so close it's only 1mm bigger so for the grief and added expense of getting new seats cut it's not worth it in my opinion.

 

[Jonny69]

I admire your courage old bean, must be a nightmare to work on, good job it doesn't have all the technical mumbo jumbo of today!

Actually it's not too bad to work on because there isn't much to it. The main problem is rusted head studs because I've had to beat the living daylights out of it to get the head off

Also that head is just asking for a bit of DIY porting, or at least a damn good clean up and a new set of valve guides please tell me your gonna get the guides replaced whilst at the machine shop, they are dirt cheap and could save you a lot of problems in the long run.

Very very nice manifolds though, very tasty...

The guides are fine as it goes. Because the valves are in the block the guides are very long and not prone to wear. The springs are a bit knackered though, I'll have to replace them with some good uprated jobbies to cope with the added combustion pressure

As for the port porting I'm in two minds. The biggest valves I can get are only 1mm larger on the inlets so that's not worth it for the bother and expense IMO, so the bigger ports won't make much difference. The more important work is inside the chamber so the bore can suck in a better charge.

 

[Jonny69]

Are you (or have you already and I've missed the post?) changing the brakes? I seem to remember an opening thread discussing how they were... barely adequate?

Not changing the brakes

Sounds like madness but we're not talking huge horsepower here. It'll be lively and need to be driven with a bit more respect from now on, but since all my braking system is new and I did the kingpins the brakes work a treat

 

[Jonny69]

Needs de-tangoing tbh.

That's illegal, it's like tampering with chassis numbers

 

[Jonny69]

First mechanical disaster

I was trying to get the distributor out but it was stuck fast. The securing screw was a slotted screw and it was rusted in so because it's now a spare head I drilled the top off the screw. Still couldn't get the dizzy to move so did the routine of dousing it in WD40, wriggled it, nothing, more WD, tappity tap tap with a clubhammer, bit more tapping and it appeared to come free but was a bit wobbly and I still couldn't pull it out the head.

Last night I resorted to a hydraulic press. Juts as well I did because it was pump pump pump, any minute now, pump pump pump, oh come on pleeeeaaaase... pump pum*BANG!* and it shifted about 3mm. Then pump pump pump *BANG*, pump pump pump *BANG* and it finally dropped out.

As I suspected I broke the casing from tapping it a bit too keenly:

So I won't bugger about with the other one, I'll just put it straight on the press

Shame because this is a good dizzy and the other one will need the guts transferring from this one.

 

[Jonny69]

Not quite as simple as not having one though

 

[Jonny69]

I already have a pair of SU's don't forget, though it's easy enough to jet them so it'll run on alcohol or paint thinners

 

[Jonny69]

On with the build...

First task is to get the old head studs out. I would have to hammer the head back on because they are rusted and bent and I don't want that so I'm going to replace them with shiny new straight items. I was a bit worried about them shifting but the oldest trick in the book worked on all of them so I was happy. Basically wind a nut on the thread, hold it with a spanner and crank another nut onto it really tight. Then 99% of the time you can undo the whole thing with the bottom nut:

To get the nut back off is a matter of mole grips round the stud and undo the nut:

Luckily it was only the last one that was REALLY tight and mangled up:

Now I want to take the valves out. I had to buy a slim valve spring compressor to do this because the springs are incredibly small in this engine and my old one wouldn't go in. Normally what you've got is a retainers at the end of the valve with a pair of tapered collets that hold it on the end of the valve. You compress the spring and the two collets pop out and you can withdraw the spring. It's a bit different on this engine because the end of the valve is tapered itself and the retainer has a slot cut out of one side and you have to pull it out with pliers. It's fiddle and requires a bit of brute force:

 

[Jonny69]

You have to jam the compressor between the bottom two coils of the valve spring:

Then grab the retainer with a pair of needle nose pliers:

Then pull the valve up like the top picture and get a hold of the spring with pliers and yank it out:

The valve then doesn't just come out because it's tapered at the end so it won't fit through the valve guide. This took a bit of head scratching but the valve guide is in two pieces and is pressed into place. One has to drift it out with a special tool, or in my case a clubhammer and a couple of screwdrivers. This is what it looks like when out:

 

[Jonny69]

I spotted a flow improvement opportunity here. Take a look at this very poor photo and you can see the top of the valve guide protrudes right into the port, semi blocking it up:

Well I'm not having that, so it's going on the lathe and it's coming off. There's still plenty of length on it to support the valve so that's free extra flow to me.

Lining up the valve springs I spot a little inconsistency:

Apart from the fact that they are about as strong as radio controlled car springs they are all different lengths so I will replace them all for uprated items. There is no way the standard items will be able to cope with increased revs, these ones are destined for a pair of spring loaded shoes or something.

One major annoyance is that this engine has solid cam tappets and you can't adjust the valve tolerances. To reduce the gap you have to grind the valve seats to make the valve drop down a bit and to increase the gap you have to get the end of the valve stem ground back. This means that as it stands I can't use my high lift cam because I will need different length valves and the process of getting them to the right ground length isn't something I can do at home, which goes against the aim of this project. Luckily Small Ford Spares do aftermarket ajustable tappets which is a lifesaver, by no means cheap, but it means I can use the cam afterall! Phew!

After a quick cleanup I can see that the surface of the block is good, the valve seats are all in good condition despite being used with unleaded fuel and the pistons are in good condition. There was hardly any carbon in there at all and the bores are in very good condition. All good news.

Final job was to flip it upside down and strip the block bare. Took the sump off, removed the flywheel and timing cover and started scraping all the old gaskets off. I'll be taking the cam, crank and pistons out next so they don't get contaminated with grinding paste or any of the muck when I start relieving the bore edges, then it's out with the power tools to do the fun bit. Mwahahahahah!!!!!

 

[Jonny69]

You going to clean up all the outside of the block to make it look nicer?

Probably not

 

[Jonny69]

I am just amazed that you can actualy buy tuning parts for these engines! I've seen stronger springs inside a ballpoint pen than those valve springs

Are the crank, rods and pistons up to an increase in RPM? A lot of engines of this era had cranks that looked like a bent bit of coat hanger. Is it a 3 or 5 bearing crank?

3 bearings and alledgedly it's safe up to 7000rpm

I have to admit I won't be taking it up there but the cam is ground to let it up to 6000rpm rather than the wheezy 4500rpm. I guess the way to look at it is they are tiny tiny pistons on a long stroke. They are only about 62mm diameter and weigh nothing.

At the end of the day if it breaks it breaks, I'll just have to build another one

Haha, even a sleeper inside the engine bay, just need to hide the aquaplane stuff.

Under an old blanket

 

[Jonny69]

Yeah it's a funny old thing with the tappets. Maybe because the valve seats used to pit up when they were using 2-Star petrol so they had to re-seat them anyway? I don't know. The 100E engine has adjustable ones though damn it's eyeballs. Just to make things harder for me than they have to be

Anyway, finished stripping the engine. Took the cam, crank, oil pump and pistons out now so it's a bare block. Tomorrows job is to get some Gunk and give it a damn good clean all over then I can do that grinding. I think I might give it a paint after all, for the sake of a fiver in paint while it's out in bits...

So when you take a cam out and you haven't got a manual it's a good idea to take a note what way round it goes in. The easiest way to do this is to turn it so the no.1 piston is at top dead centre (TDC) on its firing stroke and make a mark with some white paint, or in my case some Tippex which I stole back when I was working at Marconi. That was a long time ago but I still steal things:

It's also a good idea to mark your pistons so they go back in the right bores, this saves you having to re-balance the engine but more importantly the bottom ends go back on the right crank journals. So make sure you also keep the big end shells round the right way and with the correct conrod:

With a bit of luck over the weekend I'll also get to take a grinder to the block and relieve it where I deem fit, then next week I just have to order some bits and get it assembled

Edit: by the way I don't read The Mail, it was in the recycling bin downstairs and I needed a paper to soak up any excess oil...