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

[david_white]

Re: A race bmw 316, now S14 powered again!

Fingers crossed then that the engine should be in good shape. As you say its not worth not checking the bearings etc after a hard seasons racing.
Hope the jenveys are ok, bloody stupid bmw throttle pedals

Hope to come up and see how you're getting on before it gets too cold.

[Graham]

Re: A race bmw 316, now S14 powered again!

Hope the jenveys are ok,

they are , the stop just needed a tweek with a pair of pliers.

[Arieke]

Re: A race bmw 316, now S14 powered again!

the $64 question is do i just tickle it or hot it up a bit more by getting a 302 degree cam and fitting that on the intake and moving the current 292 to the exhaust which currently has a 284 cam,

a question, if you have a DOHC, you mostly have to buy the cams in pairs. I bought 2 290 cam for my engine. Is my setup going to be better if i use inlet 290 and exhaust 264? Or is you're option just to do it cheaper?

[Graham]

Re: A race bmw 316, now S14 powered again!

a question, if you have a DOHC, you mostly have to buy the cams in pairs. I bought 2 290 cam for my engine. Is my setup going to be better if i use inlet 290 and exhaust 264? Or is you're option just to do it cheaper?

difficult to say, most engine dont need as much exhaust cam as inlet, my engine has particulary good exhaust flow so it really doesnt need loads of exhaust cam,

i would of thought with your engine a 290 and 264 would be a bit too far apart

[Arieke]

Re: A race bmw 316, now S14 powered again!

oke, thanks.

if i want something around 275-280 i have to find somebody that make custom cams. I'll do with the 2x 290.

maybe when i upgrade the engine more I only need 1 cam :-)

[Graham]

Re: A race bmw 316, now S14 powered again!

ok had a little play today, and bolted the slide throttles on, with a couple of cable ties to hold the fuel rail, and a quick reconfig of the ecu to read the linear throttle pot, it ran i didnt dare rev it because it was late, and it was only lashed together, but im pleased to say it seemed good, i was a bit worried it might want to idle at a zillion revs as slide throttles often leak air, as it happens it idled very slow until i wound the throttle stop out a bit, it idled very nicely though.

one it was warmed up i did a compresion test, 170psi on all cylinders, which is probably rather low considering the cr, but then again pistons with only one compression ring will give low readings at idle/cranking, so i did a leakage test, 50% on all cylinders, which is rather high, but then again is it? with normal pistons on an engine thats done a good bit of work you would expect to see 20% perhaps more, does half the rings mean twice the leakage?????????????

[RWD fords rule]

Re: A race bmw 316, now S14 powered again!

Idling very well with the slide throttle's, I would imagine you are correct about the rings needing a lot higher rpm to seal than cranking and giving low cylinder pressure reading + very high leakage, but seeing the power your engine made it had to have a pretty good seal

If it was leaking really bad I would expect trouble with blowing out oil even with the dry sump pump and twin scavenge, are you running any crankcase vacuum with a sealed crankcase system or are you venting it to air? Should be able to get 10 to 12" vacuum with a sealed system, but again idle vacuum could be a lot lower with single rings, an email to SBD about what cranking pressure to expect might help as they run single ring pistons in some of their higher spec engines

[Graham]

Re: A race bmw 316, now S14 powered again!

yeah i'd thought about talking to sbd about rings, i used to run a sealed system on the 8v but reverted to open for the 16v as it wasnt oil tight, although i didnt meassure it at idle the pump is still pulling a vacuum in the system

EDIT, i just spoke to sbd, and they said it can be hard to get accurate leakage tests on single ring pistons but but they normally only see about 20% perhaps 25% so yes i do have a lot of leakage! by way of contrast i leak tested dazzles 2.2 pinto after just a short while on the rollers and that only had 10%

[RWD fords rule]

Re: A race bmw 316, now S14 powered again!

Bugger, at least you know where you stand now, could make a lot more power for you with a different set of pistons, not cheap I know but what else can you do

[Graham]

Re: A race bmw 316, now S14 powered again!

i'll just re ring it, this years induction system hasnt allowed me to use filters and as the whole of the engine and most of the engine bay has gained a thick dirty gritty coating, it a fair bet a lot of its gone in the engine, i'll be able to filter the new set up

the ultimate plan involves a new block, longer rods and custom pistons but that probably not going to happen until about 2015!

[Toymex]

Re: A race bmw 316, now S14 powered again!

How do you do a leak test Graham i run the nova without filters so might have the same issues

[Graham]

Re: A race bmw 316, now S14 powered again!

i got a snap on one but this does same thing http://www.machinemart.co.uk/shop/pr...tester-long-re

basically you put a piston at tdc on its compression stroke and pressurise the cylinder with compressed air the kit will tell you the % of leakage

[Toymex]

Re: A race bmw 316, now S14 powered again!

Ok thanks Graham i will see if my mate andy has 1

i got a snap on one but this does same thing http://www.machinemart.co.uk/shop/pr...tester-long-re

basically you put a piston at tdc on its compression stroke and pressurise the cylinder with compressed air the kit will tell you the % of leakage

[Roadsport]

Re: A race bmw 316, now S14 powered again!

yeah i'd thought about talking to sbd about rings, i used to run a sealed system on the 8v but reverted to open for the 16v as it wasnt oil tight, although i didnt meassure it at idle the pump is still pulling a vacuum in the system

Sorry to stray off topic here but what do you mean by saying it wasnt oil tight hense going with the open system?

[Graham]

Re: A race bmw 316, now S14 powered again!

it leaked oil!

with the 8 valve the engine ran sealed no breathers other than the scavenge on the pump and was perfectly oil tight, as a 16v it leaked, so i ran the engine with an open breather, what i dont know was whether it leaked oil because of a poor seal, or that that the combination of more power and single compression ring pistons meant the drysump pump could no longer keep a vacuum in the engine so with a blocked breather it pressurized the oil out the engine