It’s another technical video today guys and a worth while one. We show how important it is to check and size every engine component as you build or catastrophic failure may occur, as proven on the freshly built COSWORTH engine .
Another really good informative episode especially being a cossie. I like to see how things have been done in the past and mistakes made, your knowledge is great and your putting some good and interesting videos up now.
Well Lee there is always something that puts a spanner in the works ..some very fine precision measurements there to make sure everything works correctly 👍👍👍
@@paulhancock3844 Yes I checked my apprentice book from 1981 and the main bearing and big end shells we hand finished were for the A series Leyland and Triumph 6 cyl . Minor journal scores were to be removed with emery cloth and the next oversize bearings fitted , with blue , and scraped back untill there were no high spots and things rotated free . Very low power engines and in a commercial environment , not a racetrack.
Cheers Lee, another good ‘un. Lee talking about big end bearings then saying bearing in mind guys!, but anyway, people do the work on these Cosworths and it’s always other people following up putting the job right.
4:03 in your video, you can see a dark line around that section of the top of Bore #1 between the wire and piston where the piece broke off. Definitely broken before you remove the piston, caught the rings and chipped right out. Nuts!!
With aftermarket rods, it's always good to have it checked out before installation. Sometimes they are not perfect off the production line. 9 out of 10 times. They're inspected by human and as we know we are not perfect, especially if we're having a bad day.
I seem to remember that the Dick Johnson Racing Cosworth Sierra's supposedly ran 5.4:1 compression, and made 90hp on the dyno without the turbo. Once the turbo was put on, 600+. At the time they were building them, they were the fastest Sierra's in the world.
The DJR Sierra's engine was very powerful at peak boost, however I recall comments provided by John Bowe where he stated the DJR Sierra was a very difficult car to drive at speed because the power arrival was huge but 'somewhat delayed' which also created an increased propensity to 'torch' its rear (undersized) tyres. In any case, the DJR Sierras were successful courtesy of some really talented drivers that earnt their money on race day.
@@georgebettiol8338 I've heard JB make the same comments, along with DJ himself. I also seem to recall that the DJR Sierra's were taken to the UK and won the championship there
@@theshed8802 DJR did not win a UK championship. If my recollection serves me correctly, Johnson and Bowe, in a shared car, competed in one UK race - was fastest and took pole but unfortunatley succumbed to an engine failure - which was a shame.
@@georgebettiol8338 I did some work on their blocks. The boost was so high I recall once seeing the whole side of the block cracked horizontally when I flooded it in the dark room. No need to take the black light off the nearby wall, the crack filled with that much florescence from the mag field, the light on the wall was close enough. I went and grabbed the shop steward, took him to the doorway and just pointed, no need to go in. Normally you'd be bent over the blocks straining your eyes looking for floresing cracks. The head studs ran way down into the bottom of the block or through, cant remember which. So the engine was like a hamburger and the head studs held it all together from bottom and top. I guess when you're pushing 140+hp a cylinder the sides may bulge and sauce will escape. Oh, in this vid if the block is 0.004 oversize and they run a 3 thou interference the result is 1 thou clearance not 7 as said, but I figured that was a slip of the tongue over what he new being correct anyway. On swapping from cast iron to ductile, you can (probably should) drop the interference. Gray iron has a CTE of 5.8 and Ductile 6.4 so the sleeve will want to grow faster then the block by temperature. Given the sleeve already faces the combustion energy and passes it out to the block it has a higher embedded energy so greater size change. I also saw instances where the "Tophat" of the liner had cracked away from the sleeve and without caring to much put this down to internal thermal shear forces by the varying cross section. It's also why the "Tophat" has a radii undercut however sometimes it just isn't enough.
Your customer is bloody lucky - a shed load of issues that could all cause major damage, and it would be typical that when one goes it causes the others to happen leading to a complete failure and scrap of block, crank, and rods
Wow.Those pistons are proper agrictural design.I like them assuming they are non interference with the valves.Also a bowled piston head concentrates flame travel within the bowl and minimise blow by.
It's my engine that Lee is refurbing. The pistons are J.E. forged items from the USA. They have a order number on the underside and J.E pistons told me that they were custom made for Capricorn Auto's with a 92mm dia and 6.5:1 CR back in 2003 ! 😮
@shivadow it's a 90's Sierra Cosworth engine - history unknown. The 92mm is max overbore and 6.5:1 is way too low for my needs. Hence the need for replacement liners and going back to the stock bore & CR. The engine is being fitted to my '74 Mk1 Ford Escort. It only weighs 900kg's wet . It won't need that much boost to haul it along 😉
Called Wills rings if I remember correctly? Paul Emery used them to overcome problems with the head gaskets on Hillman Imps in the 60s Paul tuftrided or nitrided the cranks to overcome bearing problems
You recently mentioned my comments 'not seeing much work' as a criticism which of course it wasn't! It would be nice to see an engine being rebuilt with commentary. Of course this work might be boring to those who are advanced in engine building but I'm sure there are many who would enjoy watching it.
Hi Just wondered if you use the conrod bolt stretch method as recommended by ARP instead of a straight torque wrench setting. Loving the Channel Cheers Tim
Back in the 70s we always used a torque setting, but we were under strict instructions to follow a precise lubrication schedule on both the bolt threads and under the bolt heads - and we never had a problem (this was on F2 engines and BDAs). However, I later switched to bolt stretch measurement on bolts that were accessible from either end. I carried out a little bit of research which revealed quite substantial variations in bolt stretch for the same torque figure, all caused by differences in friction between the threads and under the bolt heads.
Several problems, but fortunately nothing "terminal". Personally, I prefer to step the bore at the bottom rather than use top hat liners, but that is really just a personal preference; of course, in this case you have no choice anyway because the bore is now full diameter right to the bottom. The one thing I can say from experience is that with just a plain liner, you are almost guaranteed to get liner slippage on any sort of performance engine.
I've got an idea for your next merch a t-shirt that says on the front, "remember to always check your rod!" And on the back it says, "you don't want it as loose as a prick in a bucket!"
Hi guys, are you ever going to purchase a proper block boring surfacing machine? The setup you have looks pretty ancient although it still does a good job.
@@paulhancock3844 Getting the right tool for the job and getting out of the dinosaur age is what I’m talking about, not saying they need a 5 axis machining center but doing the deck and bores in one setup is just doing it right. Mount the block in a jig by picking up on the main tunnel is just getting into this century and will be faster and more accurate. Decking on a mill then mounting that boring bar onto the block is so outdated it’s not even funny. And don’t get me started on facing flywheels on the lathe.
The 16v twin cam Cosworth YB engine uses the (European) 2.0 'pinto" block as its base - with some small differences. This engine is a later '200' block used exclusively on the 4x4 derivatives of the Sierra & Escort Cosworth and has increased strength over other versions. All Sierra and Escort Cosworths were turbocharged. Many people do convert them to Non turbo
Cosworth picked the best 205 blocks to use. They were graded and there was 4 numbers somewhere denoting the bore grade. Later 200 block/ head loads better everyone uses these.
Will the cosworth yb heads easily bolt onto reg 2.0 blocks.this would go into a 74 pinto with a 2.0 motor and a c4 auto or 4 speed manual transmission or t9 5 speed man adapted to it
There is a possibility the liner you removed was modified from something like a small Kubota diesel or something similar as many 'industrial' engines have replaceable liners. Depending on the length, it could also have been from a motorcycle? (I've been swapping motorcycle liners in alloy cylinders since around 1975 when I did my first re-bore)
So did the top of the wire groove edge break off when you removed the wire? When we look at the top of the block before you removed the cracks and pistons it doesn’t look like the edge has cracked off?
I really need some measurements on where to place the valve reliefs on the pistons for the YB, has anybody got them? I have emailed Barum but am yet to get a reply, which I do understand if I'm just a nuisance.
There is a need to clean (machine) the bore and ensure the finish is consistant thoughout. Even adopting a '+15 thousands over' would be a very risky proposition.
Do you have a policy that only regersted machanics fit and start rebuild engines, if not, no warranty will be given. Because this is what happens in Australia. Alot less stress and bullshit. No mechanic, no warranty
The 200 block is out of a 4wd Cosworth. You can run a lot more power on a 200 block. A 205 block is out of a 2wd Cosworth. And the 200 block is more expensive 😆