A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

[caprimentle]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

ooooooo shiney bits in theory you wont need to do any machining then, have you worked out what sort of compression your gonna get with these pistons?

[david_white]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

Yikes, those pistons are a bit special, someone has stolen the skirts
They are gonna rattle about nicely, a bit of piston slap? Hope they don't take you over the db noise limits

In all seriousness those look lovely, should be perfect, just try to get him to find the rings or report it to ebay (you're too nice).

[Graham]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

in theory you wont need to do any machining then, have you worked out what sort of compression your gonna get with these pistons?

shouldnt have to machine the pistons, compression i've not fully worked out yet, they are suposed to give 12.8:, but thats on a 2.5 not a 2.6 bottom end, so they would give a lot more except they will be on the wrong (shorter) rods which drops them down the bores a couple of mm so it will be nothing like 12.8, but if i swap the very thick std headgasket for a thin ferriday compression shoould be about right, just got to get the block bored out a bit, so i can put them in and burette the above piston volume and work things out properly

[Graham]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

Yikes, those pistons are a bit special, someone has stolen the skirts
They are gonna rattle about nicely, a bit of piston slap?

they certainly will rattle, look at the pin boss and see how far ofset it is, only its offset AWAY from the thrust side to try and reduce angle on the rod, but i guess it was needed when trying to rev a big bore long stroke motor to 10K+ afterall these are DTM spec just need the rest of the DTM spec bits to match

edit, i just weighed one with pin 385g as opposed to last years pistons which were 505g thats a massive difference, which would be even bigger if i had rings on the pistons, the lightness of then should more than make up for the longer stroke in the rod strength/revability of the motor

[Tristan]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

they certainly will rattle, look at the pin boss and see how far ofset it is, only its offset AWAY from the thrust side to try and reduce angle on the rod, but i guess it was needed when trying to rev a big bore long stroke motor to 10K+ afterall these are DTM spec just need the rest of the DTM spec bits to match

edit, i just weighed one with pin 385g as opposed to last years pistons which were 505g thats a massive difference, which would be even bigger if i had rings on the pistons, the lightness of then should more than make up for the longer stroke in the rod strength/revability of the motor

they're not pistons , they're just ring carriers! lol

[Roadsport]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

Wow looks very good! I want pistons with that compression height too. What is the height?

[Graham]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

25mm

[Graham]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

they're not pistons , they're just ring carriers! lol

thats what the chap who will bore the block for me said

[Graham]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

another 5hours of grinding and im almost there the portings done, i just need to do some detailed work on the short side, boy am i sick of grinding aluminium, so much so im really looking forward to grinding a pinto head LOL! as per usual on teh last port i broke through, fortunatly this time only into the end on a manifold stud hole so its of no consiquence.





i've also made a start on the inlet adapter plate transferring the manifold and head shapes to a polycarb off cut,to use as a template, i can feel plenty more hours grinding coming on!!!

[david_white]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

another 5hours of grinding and im almost there the portings done, i just need to do some detailed work on the short side, boy am i sick of grinding aluminium, so much so im really looking forward to grinding a pinto head LOL!

Oh, you don't wanna know what I'm picking up today then. Oh well at least YB heads dont need much porting for N/A

Cant wait to see this head up close next week

[RWD fords rule]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

The crank and rods won't be under any strain whatsoever with those pistons! that is a massive weight saving

She'l easily go to 9k now if the valve springs etc will take it

Will be very interested to see how you get on with 1 compression ring, sbd use pistons like that in their full on XE and Duratec engines with 1 compression ring to get more bhp, less friction.

[Graham]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

Will be very interested to see how you get on with 1 compression ring, sbd use pistons like that in their full on XE and Duratec engines with 1 compression ring to get more bhp, less friction.

me to although i doubt i'l be revving it hard enough to fully benifit from a single ring.

dunno what revs std valve springs will stand although i suspect they will take anything the 292 inlet can will revto as schrick only recomend there springs rather than saying you have to use them

[Graham]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

a bit more progress, having started to make an adaptor plate, ive changed my mind, after starting it i found the missing OE inlet manifold rubber mounting thingy that i've spent 6 months looking for, so i abandoned the thick adaptor not really wanting to hang a couple of kgs of alloy on the side of the head anyway, plus with limited space it was really difficult trying to get all the drillings in the right place and leave space to get a gas tight seal



heres one of the OE inlet throttle body mounts which has been opened out to match the ported head on an unported head



so instead made 4 small adaptors to go on the manifold rubbers




here we are m10 manifold and jenveys on the s14, still got to put the ports in the adapters but due to the m10 having taller but narrower ports i wil probably end up filling in the bottom of the manifold with some jb weld, otherwise im going to end up with a nasty sharp turn in manifolding where it meets the port

[Tristan]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

is JB weld that good? I've a couple ofspots I could do with building up in my (steel) intake mani , for less turbulence , but was worried about lumps of stuff entering the engine .

[exboyracer]

Re: A race bmw 316, 240bhp Atmo M10 now going s14 power!

Yeah JB weld is good, I used to to build up the port floor on my xflow intake manifold. I must admit I did cheat slightly and fitted some roll pins to give it something to grip!

Nice work Graham, that picture of the port adapter versus the standard port really shows how much material you had to remove!