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

[Graham]

Re: a very powerfull and troublesome bmw 316

still no real progess but these have turned up

[david_white]

Re: a very powerfull and troublesome bmw 316

Niiiiice

[Graham]

Re: a very powerfull and troublesome bmw 316

more progress but only in terms of ££££ spent

[david_white]

Re: a very powerfull and troublesome bmw 316

Is that a single or twin scavenge tank Graham, I assume your system is twin like my pinto one

[Graham]

Re: a very powerfull and troublesome bmw 316

the tank is single scavenge BUT my pump and yours are both the same, they are twin scavange but use a single 3/4 return to the tank

[david_white]

Re: a very powerfull and troublesome bmw 316

the tank is single scavenge BUT my pump and yours are both the same, they are twin scavange but use a single 3/4 return to the tank

Do the pipes from the scavenge 'T' together then into one

[Graham]

Re: a very powerfull and troublesome bmw 316

no, there are two scavenge pipes going into the pump, but only one comes out as they are linked internally in the pump

[Graham]

Re: a very powerfull and troublesome bmw 316

playing with linfords dry sump pump gave me the inputus i needed to do some meassuring and start making mounting brackets etc for my own engines pump

[Graham]

Re: a very powerfull and troublesome bmw 316

more money spent, my new cam has arrived, schrick 336/328 its the most mental cam you can get for the bmw m10 engine, it was a wonking great 336 degree duration, and 0.220 lift on overlap, just look at those cam lobes




its going to be a bit of a voyage of discovery, i have used this cam before, well a slightly tweeked version which had slightly less overlap, on a 2.0 bottom end it had just about zilch power below 4k, woke up at abou 5, but really only worked between 5,500, and 8,200 i would gues on a 2.5 bottom end its going to work at about 1500-2000 rpm lower

[mk2stu]

Re: a very powerfull and troublesome bmw 316

Cool work mate
hows ure bottom end coming together or are you still waiting fo parts?
That cam looks good pretty lairy profile!!

[Graham]

Re: a very powerfull and troublesome bmw 316

the blocks gone away to be bored to suit the new pistons, and i've been playing with heads on the flow bench,

http://www.turbosport.co.uk/showthread.php?p=1536241#post1536241

havng come up with the best shape i've managed to improve it a bit,
the graph is actually inverted so the lower the columes the better the flow

[Graham]

Re: a very powerfull and troublesome bmw 316

i've been playing with pistons, unlike the linford pinto its not really practical to to them with valves shapped into cutters because of the depth of cutouts i need, also the cylinderhead design means you cant put a drill straight on the valve stem with the valve in possition.

luckily i keep the old pistons from my last m10 engine and modofied one so i could use it to make a jig to old my new ones in the right positions



finished jig with old piston in it being used to position fly cutter




in these pics im doing the exhaust cutouts, the bearing sheels you see are spscing the piston over, the reason for them is when i made the jig i diceded in addition to the diameter of the pistonsto use the gudgen pins as loction /reference points but forgot about the pin off set, so without them the jig only worked correctly for the inlet valves, and that was easiler than making another jig



here you can see from when an exhaust valve touched after a big end failure, that despite being professionally done the exhaust cut outs were actually quite a long way off course







and the inlets were done twice as they werent deep enough for the most mental cam, incidentally from the factory these pistons dont have cutouts!







one of the old pistons turned down the the same overall height as the new ones




as you can see from the piston on the lefti made the old piston a collar to take its diameter up from 89.5mm to 95mm so the jig would be the right size


you can there is no skirt left on the old piston, due to the massively reduced compression height of my new ones, this is beacuse im using a rod 10mm longer and a crank with 7mm more stroke



one finished set of pistons, although once i've done a trial build theres no guarentee i wont have to take a bit more out of them.

before anyone asks i donrt want to do anyone elses pistons i hate doing this job its so easy to end up with a scrap piston, if fact one of them has a small dig out of it which it shouldnt as a result of the cutter working loose

[alex savill]

Re: a very powerfull and troublesome bmw 316

WIZZARD

[lee 1]

Re: a very powerfull and troublesome bmw 316

Interesting read as per normal Graham

Are you sure you don't want to do my valve cut outs

[Graham]

Re: a very powerfull and troublesome bmw 316

if i dont like doing valve cutouts in pistons i even less like putting them in a lathe which is what happened next...........

my accralitte piston on the auzzy steel rod


after fitting crank rods and pistons i meassured the piston protrusions, unfortunately no2 stuck out the block about 0.010" more than the rest,



moving the piston and rod to another cylinder showed the difference isnt in the crank pin, either the rod or piston for no 2 is a bit longer,



the bit i hate, putting pistons in a lathe, you cant really grip them tight so they are prone to flying out, especially with a lathe like mine which has a chuck which will only just hold a 95mm piston, normally i get a mate to machine piston crowns, as he's quite cheap and can do it quickly and accurately with no risk of them flying accross the room, but as i only wanted to take 0.010 off one of them, i decided to risk it

i reallly did myself at one point because i forgot to take the gudgen pin out, which flew out all on its own as the machining warmed the piston up