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

[RWD fords rule]

Re: A race bmw 316, 240bhp Atmo M10

The roll over jig is really handy for welding it plates and rollcage etc, good idea with the engine stand
I think the lower you make the pivot oint in the shell the better as when you start bolting in the rear axle and front struts etc the bottom of the car gets really heavy and hard to keep hold of when you are rotating the shell, pretty easy with 2 people though.

[Cosnada]

Re: A race bmw 316, 240bhp Atmo M10

I have just read this whole thread from the begining again - awesome history with both victories and disappointments on the track and personally. You are a true inspiration to others and myself included. You show great patience and tenacity where I know others would have definately thrown the towel in.

Its a shame you went from turbo power to NA as I am a big fan of snails - just my preference. Glad you are happier racing now and that you are mixing with the rest of the field and not on a hiding to nothing trying to beat 4wd class A cars.

The new shell looks a good base now to build up to the new spec required. I hope your budget will always be able to match your enthusiasm. I will now keep a close eye on this thread to watch progress as some of your engineering fixes and the way you find solutions to problems you encounter are a real enlightenment. Guru is an apt nick name indeed.

Keep up the good work Graham and all the best with the new build

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

cheers m8 nice of you to say,

IF i had the money i would still be running a turbo motor, the trouble is to run a truly competitive turbo motor is way beyond my means and i've got a good job income-wise!

i know two competitors that run serious in the same race series with silly horsepower turbos that have spent 30K on engines

[caprimentle]

Re: A race bmw 316, 240bhp Atmo M10

do you not need the bushes then?

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

do you not need the bushes then?

not anymore the beam bushes are now an integral built in part of the beam

[caprimentle]

Re: A race bmw 316, 240bhp Atmo M10

aahhh very good idea, i like that

[Cosnada]

Re: A race bmw 316, 240bhp Atmo M10

cheers m8 nice of you to say,

IF i had the money i would still be running a turbo motor, the trouble is to run a truly competitive turbo motor is way beyond my means and i've got a good job income-wise!

i know two competitors that run serious in the same race series with silly horsepower turbos that have spent 30K on engines

hey graham, now that you are not running in class b and and also normally aspirated, should you need funds then i may be interested in your t38. Just a thought for you to bear in mind :-)

[david_white]

Re: A race bmw 316, 240bhp Atmo M10

hey graham, now that you are not running in class b and and also normally aspirated, should you need funds then i may be interested in your t38. Just a thought for you to bear in mind :-)

I think thats long gone..

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

I think thats long gone..

your be right on that one dave

[Cosnada]

Re: A race bmw 316, 240bhp Atmo M10

Worth an ask even as a long shot though

Keep us updated with the new shell build

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

not much of an update, but i spent an afternoon playing with various heads on a flow bench





i got soem very interesting results, a std head is like a std pinto and flows about 85cfm, we flowed the head that was actually on my race car, it topped out at 115cfm, which is ok but not great, what was noticalbe though is that it flowed really well at low medium valve lifts, reworking another head which had the same porting, i got make flow upto 118 cfm, but we lost out in the midrange, trying a bit more we gained another cfm at the top end, but lost several more in the midrange.

on another tact we tryed a head with a smaller rounder more down draft port, that flowed 122 cfm at full lift, but was worse than my normal race head everywhere below 0.400 lift, working even more at the same head full lift flow jumped to 128cfm, but again flowed still less at low and mid lifts,

exhaust flows suprised us, the head with the smaller round ports flowed 91cfm (with obvious room for improvement) where as the nice big oval ports on the other heads only flowed 85cfm

i guess its fair to say this engine is working well inspite of the head!

as for which head to go with its difficult to say, with a cam only lifting to 0.500 its hard to see how a head which flows worse everywhere upto 0.400 can work better than one that better upto 0.400.

when i got the calculator out and averaged the flow figs for the various shapes the best head was the one with least full lift flow but only by one or two cfm

whats very clear is that an inlet port which has a nice rounded shape works well at low medium lifts and one with a shape more like the leading edge of an aerofoil section flows really well at high lifts even though it doesnt look like it would. perhaps the answer is to try an even bigger inlet valve and try for a halfway house between the two designs

[Group4_Mark2]

Re: A race bmw 316, 240bhp Atmo M10

Hello Graham,

What work did you do on the valve seat area to improve low lift flow?

I was watching a presentation by David Vizard on Youtube recently and he was talking about the benifits of using a 30 degree valve seat. he explained that the 30 degrees improved low lift flow by up to 20% over a conventional 45 degree seat. He also explained how to use a 45 degree cut into the bowl followed by a radius so that high lift flow was un effected by the 30 degree seat cut.

By the way the videos are

What do you think?


A nice article by David Vizard here also

http://www.popularhotrodding.com/tech/0610phr_cylinder_head_porting/index.html

Regards
Tom

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

What work did you do on the valve seat area to improve low lift flow?

i didnt spend much time working on valve seats it was the port shape we were concentrating on as we were mainly trying to work out which head tyoe and port design to go with, but one of the heads i got dave to test a few weeks ago, this head orgonally had a 40mm valve but was opened up to accept a 46mm, such an increase took it beyond what the seat would stand (alloy head) so the valve just seated on a very very narrow 45 degree seat directly on the alloy, when we next tested it i had had an insert put in hich had a loverly 3 angle job on it, flow at 0.050 was up 5cfm, by 0.100 flow gain was only 1cfm.

i suspect the really low lift flows are of much less importance on an engine with a fast lifting long duration cam simply because the valve will spend very little time in that low lift state, a std or mild road cam though would probabl;y dictate the exact opposite

[Group4_Mark2]

Re: A race bmw 316, 240bhp Atmo M10

I cant confirm this but I was told by someone who knows a lot more than me that the valve seat area can effect low lift flow quite considerably up to 0.150" lift

[Graham]

Re: A race bmw 316, 240bhp Atmo M10

i think port shape will have a lot to do with it,

on heads like these bmw and pinto ones if you have a really long radius to the short turn the flow at low/med lifts is good as the air turns the corner nicely, at higher lifts the airs trying to skate across the back of the valve and that nice rounded shape actually obstructs teh air, a lower profile port allows better high lift follow but low med lifts are disrupted as teh air no longer has a nice rounded shape to follow,

the port shape that gave really high flow at big lifts leave a very tight turn if any are is going to go round the short side of the valve,

a multivalve head which has the flow better distributed in terms of where around teh valve head it goes will prob benifit more from valve seat angles