Ha ah! You are mixing up a couple of good old Issac's Laws there. To change direction, one needs external forces. IE. Acceleration or braking. So, lightness is the key. To go round a corner, you need to maintain momentum. If you brake, or accelerate, around a corner you will change the momentum, and go off backwards or forwards, as front, or rear, grip dictates! Unless you are Stig Blomqvist!
Well I am probably just a great driver then. Or maybe not. The scienz bit. Possible proof that heavier objects exert more centrifugal force. [YOUTUBE]s7q8Z4FMGgU[/YOUTUBE]
Dan. You are obviously a great driver. From all of your trophies, I, for one, believe that this is so. You obviously don't need to bother old Issac! Just keep up the good work. Please. DAD 3/3
19.9 kg AXW ( N.A FSI 2.0 ) alloy block 83 mm bore / deck 2 mm skimmed So a STD block wil be nearly 21 kg ? The block has steel liners cast in
God why don't they nickasil the bore Isn't it suppose to be stronger and less friction then steel Now day most engine are alloy nickasil
I need to double check my AKL block as I am pretty sure the bores are nikasil plated. But saying that, BrianG did cut up a small block 16v engine and they had cast in steel liners.
IMO the ALT block is also with liners cast in Only recently found out about the steel liners. My believe was that it was an all alloy block, and it looked that way too. After buying some wossner pistons, after contacting some people/companies, everyone said : just bore / hone the bloc and drop the piston in, No coating needed ! Alusil blocs AlSi17Cu4Mg( Audi V8-V10 Blocks) have high Si content that make it work w/o coating, But my bloc is AlSi9Cu2, and made me think something was not right... searching the net, i found out that these blocs are made by Kolbenschmidt in Neckarsulm, lots info on Alusil...but very few info on ....until i took a magnet to find out
have seen pics were the liners were about 4 mm + outside mantle and another that is only 1.5 mm or so also with outside mantle 83.0mm sure , 83.5 mm most likely and 84.0 mm ? i must say this engine block will need special attention at assembly to make sure the bores keep round / crank line keeps straight ...as i feel it flex...unless a steel bloc that is rock solid.
Im making out the liner material to be centrifugal cast iron. And fitted at time of pour, then bored to finish size. Block was a 1.4 16v. BG
Aren't those alloy small block meant to be scrapped if you take the crank out for those flex reasons? Are the big block different than those small block or is there a special tool who will More or less kind off spider around the block to hold it in shape? But I found quite worrying the fact that the block hold straight because of the crank How does the block react if the engine get spun much higher than it should Or get much more torque I heard of old ducati engine talking here 916 era they had to strut the engine from the outside With some steel rods and bracket to hold the engine together as it would flex at high revs They already were putting those special sump with shorten block seen on the btcc engine On an iron or specialty metal blend engine block which can hold it s shape on it s own
I have heard that the 1.4 16v engines are not meant to have the crank removed for structural reasons! Begs the question, how did they fit it in the first place? The 1.6 16v are apparently ok to remove the crank. All seems a little ludicruous to me.
IMO, when the factory assemble an engine it will be mount in some jig / tool. all 10 crank bolts are torqued down, all at the same time and once the balance shafts/oilpump assy and the sump are mounted , it becomes a rigid block
How woiuld it hold On high state of tune engine ? Or are those engine just not good for any kind of motorsporr?
so the crank girdle must form a significant part of the structure, do they have seperate crank journals or a girdle?
Same question don't know The btcc spec engine have griddle sump some pretty extreme mods So as I said they are like bic razors Use them once then bin them no rebuilt possible Appart if you want to have a go with 9 other mate to torque all the main studs in one go lol
This method of girdling also stops cap walk, that is, the caps moving from 90 degrees to the crank axis. This is more important than making the block rigid, bit of course, it goes hand in hand with it. The ladder girdle is the only real way of stopping crank cap walk at higher rpm on the vw block design that we are stuck with. It has only two bolts part cap, and there is not more room to get two more outside them. I have checked, dont worry. To give you an Idea of a much better cap design I have inserted a picture below, this cap will take high rpm easier, and is less prone to walking off its 90 degree plane to the crank axis. And the design issues with our vw block, and cap design/locations/surrounding material, There is simply no material there to fit another pair of bolts, The actual locating pads to keep the cap in place, that is, 90degrees to crank axis are tiny, An exaggerated example of the cap walking off 90 degrees because of the loads transmitted through journal, Which directly results in the shells getting pinched, the hydrodynamic oil film collapses and thus you loose the race. Even billet caps do not offer any safe guard to cap walk, same pad area, An F1 engine below, designed from the ground up, I know we or they did not do that(305hp btcc Audi) in the quest for hp as they had to do with what they had, but, Its important all the same so Ill mention it as cap walk is important if your wanting to go all out. They use just two cap bolts like we have, but, the block comes up fully around the cap, and has very large pad areas in order to keep the cap where it it supposed to be. Infact, they used a skirt spreader tool/jig in order to fit cap as correctly as possible. From the end, notice the relief radius either side where block/cap intersect, no sharp high energy intersection which could lead to failure/cracking. Cap fitted, Once cap is fitted and torqued they then fitted studs into cap again from either side through the block skirt, these are key in tying the whole assembly together and a very clever idea. This ensured the caps did not walk at high rpm, pinching shells as above in my cutaway pictures. The stud ends can be seen below, screwed into each cap from the outside, Audi had no way of doing this with the vw block, adding material there was not really an option. So instead they shaved off the skirt flush with crank centre, then fitted the cap ladder, which ensured all the caps then stayed parallel at high/endurance rpm. An aftermarket crank girdle will not stop cap walk as the caps are still independent. But, it does give you another interference point between the girdle, the caps pair of counter-bores and the underside of the bolt heads. Better than nothing I guess, just, but not enough if your going all out as Audi did. Theres alot of things involved with stabilising the bottom end, simple once you look at them, but take figuring out all the same as to how it all can be done, pending what your dealing with. Im going to post this in the Btcc thread also as I feel it shares some info others may find interesting. BG. Ps, F1 pictures taken from F1 1986: Assembling a Ford Cosworth Formula 1 engine.
later rover v8s had the cross bolts IIRC i suppose you could cast then line bore the girdle=include the caps in it to sort out the vw effort
