Yet another project....The uncrashed spitfire

I hope so after the work of removing the motor , but at least you will have a good motor when you rebuild


have the piston rings lost thier springyness ?


have you put one ine the bore and checked the gap , this give an idea of ring/bore wear

the lines (Horizontal ones) could indicate a sizeure at some time or the engine has been standing with water in the bore
 
Bore is std at the mo and was hoping to keep it that way as i sourced an awesome set of pistons for £40 a set!! oversised ones are £150.
But it doesnt look like it will be spoke to machine shop today and he reacons it will need a bore.
Block goes to him on friday.
 
Whoa hold on... before you go spending too much money if you don't have it... :p

You can most likely get away with having the bores honed which is where they scuff them up with a set of 3 or 4 honing stones on a special tool and then use a new set of rings which you can get for peanuts. The old rings will be worn so the new ones will take up the any slack. If you get new pistons then that means you'll have to balance the engine when probably all it needs is the old rings dug out of their channels, clean all the carbon out and fit the new rings. They will be loose in there and seal nicely in the bore. The honing will take out any of those scratches but not increase the bore size noticeably.

And as said the timing chain should be tight, that's too much slack there.
 
Ahaahhhaa there is more to it.

The pistons have to go anyway cause im having the block decked by 40thou to get rid of the rescessed gasket on the block to improve reliability. This however will take the tollerances on the compression ratio too high, i.e. thinkin i will be at 12:1. So the pistons are being changed to dished ones which will bring the compression back down to a mere 10:1.
The engine is all getting balanced twice, seperate and dynamically.
Block is getting acid dipped.
And the cam is getting replaced to funky ones.

More pics

engine is now stripped to just the crank and front and back plates.

DSC00344.JPG


cam is quite worn in places

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Mains Badly worn aswell

DSC00347.JPG


That should be me dont think i will have to remove anything else before it goes away.
 
Right engine has been at machine shop for a few days now whilst i pondered piston options. Forged pistons were too tempting but eventually the financial implications persueded me off them. Engine rebuild is already gonna cost me about £700.

So i opted for these and ordered them today
155167_005_1310.jpg


American *** Dished low compression pistons, much stronger than uk spec and also will help sort out my compression ratio with the whopping skim the block is getting.
Of course i will still need custom pushrods made which will probably come from the states given that i can get a custom set of chrome alloy ones for £40!!

Quite impressive what the machinist discovered about my old pistons, they where original from 1978 and hadnt been changed, the grooves for the piston rings where twice the size they should be, the tops were badly corroded and the sides has scratches that range up to 20 thou deep, which is massive. No wonder i had no compresssion!

So back to the work that is getting done,

Block is getting a 30thou skim to get rid of the recessed gasket
Bores, bored to +19 honed out to accuratly match each piston.
Pistons weight matched
Rods Weight matched and end to end balanced.
Crank ground to +20 and tuftrided and balanced.
Flywheel lightened from 6kg to 3.5kg and balanced
Cam bearings custom made and fitted (engine not supposed to have these but every decent engine does)
Baffled sump
Dupplex Vernier Timing Chains
Kent TH5 Small journal camshaft
Kent Cam Followers


coupled with the already custom head, this should be one of the most extreme 1500 triumph engines there is.

All this work however will not give the power increases you might expect for the money, im aiming for 115bhp on stock carbs, should give 125 on delortos eventually.

However this in a car which weighs as much as most peoples engines, and it'll do 0-60 in mid to late 5s with a top end of 130mph. :D

God i must be mental spending all this money. But it is fun.
 
What

"Crank ground to +20 and tuftrided and balanced."


as I understand you grind cranks to a minus figure eg -10 thou ie under size,

if you have foud a way to grind on metal please share :D


only joking :D


the final inspection has revieled the true state of the engine eg "K" for no good



you say you must be mental for spending money I have just orderd a new "British made " lathe close to £10K
 
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Sounds good to me, should be a stormer when it's done. Is that the wildest cam you can get away with? Always get the maddest grind you can fit on your allowed valve lift.
 
Its about as high as i want to go just now, the engine really shouldnt be reved about 6k so im setting the powerband in the 2000 to 5500 range.
 
loads of new bits today but just boring bits like gaskets etc and a new oil pump.

Been puzzling on an idea of going a bit silly.

Anyone know where i can get a metro turbo inlet manifold????

Been desperatly trying to find one.
 
Well the engine supplies are almost up to stock, all bearings are here, all gaskets, pistons, rings, cam shaft should be here tomorrow, timing gear is here.
Engine work was finished on saturday, just need to pick it up and pay, rebored to +20, reground crank to +20, acid dipped and the block skimmed 40thou, flywheel lightened by 2.5kg, and the whole lot dynamically balanced.

Just need to get it back paint it and start building now, which is gonna be offset by a trip to hospital for a couple more opperations.

Getting excited about it now, kinda helps to stop me thinking about the costs had to add it up, im into 800quid now for the engine, oucha! Still the engine shop guy reacons it should run at about 125bhp which is 10 more than i expected.

Just need to finish off designing the baffle in the sump, struggling to decide how low to mount it.

IMG_2881.JPG


ignore the gun, joke on another forum.
 
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