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

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

but if what your saying is that you have the potential to get another 100 horsepower out of it plus your saving the weight as this head will be alley agaist your cast head (correct?)

both heads are alloy, infact the s14 head is heavier but with the potiental for so much more power i'll forgive it

320is s14 was only aviable in itaily and Portugal, it was still a bloody good engine though 192bhp as std!l

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

well it looks like the decision is made, i've found a head (but no cam carrier unfortunatly) £500 cash its an early one so it has small ports and will be off a 195/200 bhp motor, i could of had a big port one off a 220bhp engine but that would of been £750, i figured it as you can turn the small port one into a big port it wasnt work paying the extra.

i've just got to pop over to telford to get it!

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

right 350miles later......






no going back the cars deffo going 16v now!

i was temped by the big port head when i got there but it wasnt as complete as this one and did have some chamber damage on no4.

just a few flies in the ointment now

1 if farndon phone in the the next two weeks saying my cranks ready and can they have the balence due they will have to wait a bit because i've just spent it, that will serve them right for keeping me waiting so long

2 i dont have any pistons to suit the 16v head! although i think i can mod my spare forged 8v ones to do the job.

3 i dont have an exhaust manifold, and a normal m3 one wont fit because my cars rhd!

4 i sold my s14 throttle bodies and they will cost a fortune to replace so i think i will have to make an adaptor to adapt my 50mm jenveys

[Roadsport]

Re: A race bmw 316, 240bhp Atmo M10

On to making manifolds then?

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

On to making manifolds then?

looks like it, im hoping i can make a simple adaptor plate that will marry m10 inlet manfold to the s14, and with the exhaust im bidding on a std m3 manifold on ebay right now hoping to adapt that, a std manifold isnt ideal, but actually works well on these engines upto 270bhp, and i dont think that 2.6 minus airflow meter a slightly rased cr and only group n cams will get me to 270bhp

[Roadsport]

Re: A race bmw 316, 240bhp Atmo M10

I believe the M3 manifold is tubular to begin with? Cast item would be a handfull to convert to RHD

[Schobo]

Re: A race bmw 316, 240bhp Atmo M10

It's a pity you've sold the BMW throttle bodies...it would have been great to see your car with a cfk-airbox like the dtm e30s did in the early 90s

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

I believe the M3 manifold is tubular to begin with? Cast item would be a handfull to convert to RHD

your right it is tubular as OE

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

having got my hands on an s14 i couldnt help but play with it, the early heads which this one is one of has a small port, later evo heads have ports several mm bigger in dia, which i guessed must flow a lot more because there a 20bhp power difference which cant all be accounted for by the hotter inlet cam that went with the big port.








i opened the ports on 1 cyl at home then borrowed a flowbench, flow gains from opening the port up were huge, playing with plastoscene on the bench i figured they wanted to be bigger still, and that was the case,no real work was done at the troat end just a bit of blending where the bigger port meet the throat, i also took a little out the short side, by now gains were getting hard to find so i quit while i was ahead, im sure theres more flow to be had but i didnt want to risk removing too much or metal in the wrong place, in anycase its going together with relatively mild group N cams


.

blue line is my best peak flowing m10 head,
brown line best average flow m10
green line std early s14
purple line s14 with ports opened out to later evo spec

ignore the numbers along the bottom but numbers up the side are cfm @10inch

[Group4_Mark2]

Re: A race bmw 316, 240bhp Atmo M10

Thats a good increase in airflow. The low lift flow is almsost double the m10 head. That should effectively make the cam look much bigger as the flow will get started much sooner and finish a bit later than the lower flowing head. Should make good peak power also due the big improvement in peak flow

Rgds
Tom

[dangerousdave]

Re: A race bmw 316, 240bhp Atmo M10

Seems worthwhile already, the head as std is almost better everywhere than your best m10 head, which is what you need for the new big capacity motor And from the look of the ported one its miles better all over, theres a nice peak in the midrange where the old head was flat.

Is the porting pretty much identical to the later evo head or a bit better than that?

[david_white]

Re: A race bmw 316, 240bhp Atmo M10

Great start Graham, as Dave says its already a fair bit better than the 8v so it looks like the new engine should be very promising. In fact this thread makes me want a N/A 2.5 YB for the sierra, better cancel that turbocharger..

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

Is the porting pretty much identical to the later evo head or a bit better than that?

basically thats all i've done turn an early head into an evo, whats unusual is that 95% of the gains came from opening out the port, the final bit fromn the troat area, its usually the other way round

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

Great start Graham, as Dave says its already a fair bit better than the 8v so it looks like the new engine should be very promising. In fact this thread makes me want a N/A 2.5 YB for the sierra, better cancel that turbocharger..

dont get too excited dave, my engine will basically be all steel/forged bottom end with a std top end! to really make it fly it needs a lot more work, rick wood does a loverly cnc head for £1500 + vat plus i'll need proper proper cams, which need group A style shims etc etc, shcrick do a complete kit its 4000 euro

while i was collecting the head i got to take a peak of a bit of ex touing car kit from when bmw put the s14 in an e36, how about a variable length slide throttled inlet it used engine oil pressure to change the inlet lengths, one of the clever boxes with the kit had mountune on it

as for yours i'll build you what ever you can afford, we could just port a yb head fit some cams swap the pistons and bang it on linfords bottom end, that would be cheaper than building you a turbo motor as there no turbo to buy, and you'd still have a cracking head to sell, but real real power from a yb is goinna cost you plenty, 2.4 does sound nice though

[david_white]

Re: A race bmw 316, 240bhp Atmo M10

as for yours i'll build you what ever you can afford, we could just port a yb head fit some cams swap the pistons and bang it on linfords bottom end, that would be cheaper than building you a turbo motor as there no turbo to buy, and you'd still have a cracking head to sell, but real real power from a yb is goinna cost you plenty, 2.4 does sound nice though

Who said 2.4, I wanna BIG 4 pot You're right though, that could be an option worth looking at as I have all of the ancillaries still except an NA gearbox.

Yours should be good though, very driveable with a bit more top end punch. Will look good in the bay too
As you say its suprising how many tricks there are on GpA/touring cars, no wonder they run into the hundreds of thousands to build. The ones at prodrive recently were £125K rebuilds, and thats on top of the price of a genuine GpA M3 (pics in a mo)