M10 2L Race Engine DCOE advice

[kuroneko]

I have a car with a 2.0L race motor, 336 cam, 13:1 and 45 DCOEs.  New(ish) to me. Just picking around to see anyone is running something similar and would share their DCOE tuning setup?  I'll share mine.  Last dyno I have is below and I feel the car is running a bit lean for my taste.  But I guess that's what it takes to squeeze every ounce 220 out of this engine.  Hah!  But it wasn't done by me and before the car gets tucked-away for the winter, was thinking about getting it on the dyno and dialing the tune back a bit.     Any advice, input, ill affects of dialing it back or thoughts of any kind is appreciated.  The car obviously can't get out of it own way under 4,500 rpm. That's not a concern.  Putting a little more margin of error into the engine and longevity is. 

 

The M10 is a new motor for me and I'm getting to know it.  For me, racing is not just about the driving, it's equally about the building. I enjoy it almost as much.  Having someone build the biggest, baddest engine isn't for me.  I'll do it myself even though it might not be the optimal build and I leave things on the table. That's fine, even if mistakes get made along the way...it's part of the fun! Right now, I have an engine broken down, some initial blueprinting (by me) to figure out what I've got and it's ready to haul off to the machine shop for a cleaning and initial check.  Over the winter I'm going to build a 2nd motor for the car as a replacement/backup to anticipate a refresh of the current motor and/or prepare for possible (or inevitable) boom.   It'll be a 2.0l as well and 316 cam.  It won't be the primary engine and it's also meant to be a learning exercise for the future.  It'll be a good build but I'm not going to put Lester Owen rockers in it (for example).  The bottom end is straight-forward, I've mapped out what I want to do and how I'll go about it.  Jeremy Ireland has been super helpful on that front. VAC not so much even though I've had good experiences with them in the past.  Right now I've got an uncut E21 head so I'm just gonna roll with that.  But I'm still trying to sort out the head components (rockers and springs).  I'm intriqued by KM cams rockers and trying to zero in on the springs.  But like I said, I'm an m10 virgin and still trying to sort through what's available.  So any advice on that front is greatly appreciated. 

 

Thanks in advance.

 

Edited May 12, 2017 by kuroneko

[burndog]

At first blush without seeing the dyno HP/TQ curves it looks too rich below 4800RPM. It almost looks like your AFR table is inverse to the RPM's... Unless I am reading it wrong.

[ray_]

Something like this in the way of AFR is suggested for an S14 motor. I think I'd be very wary of running >13:1 AFRs under load.

 

Cheers,

 

 

 

 

[jrhone]

I'd seek out Ken Blasko...he may give you some advice on both tuning and motor building as he builds and races 02's.

[jireland2002]

Obviously too lean at high rpm.  You need richer high end and leaner low end.  With this set up you should try F16 e-tubes or maybe F2.  If you change tubes you'll have to change jets as well.  I'm not sure where you'll end up. Maybe up on both main and air.  

Long term you would be much better off with 48mm carbs.  Probably with 40mm chokes.  You'll get a stronger vacuum signal for the jets so tuning will be easier. 

[Preyupy]

I'm with Jeff, you should try a smaller Air Corrector first to richen it up at the top end.  A different E-Tube should help and again the F16 or F2 would be where I would go first.  Depending on what you are doing with this car 48mm carbs will help the top end but at the sacrifice of some drivability under 5000 rpm (if you think it is dead below 4500 NOW just wait to see what happens with 48mm carbs).  You said "I have a car with a 2.0L race motor, 336 cam, 13:1 and 45 DCOEs"  you didn't tell us if this is a RACE car or a STREET car with a nasty engine?  If you are trying to drive this on the street your tuning issues will be much worse that if you are just trying to get it to work on a race track. 

[TobyB]

I have run f9 E tubes, and have ended up with very small air correctors- which I agree, it looks like you need.

But that's also a really big hose for a main jet- I could never run over 36 (rules) chokes, but I was in the 

120s on the main.

 

I never let it get leaner than about 13.5- the plugs never showed bright white, but most of the tan was gone by that point-

on AvGas...

 

t

 

[Preyupy]

I have a number of 2 liter engines with 336 cams and 12-13:1 compression ratios out in the vintage racing world and your jetting is not far off, most of them are running 40mm chokes in 45DCOEs and depending on the header and air cleaner 165-175 main jets are normal and 155-175 air correctors are in the range.  Most of them run either the F16 or F2 E-tubes.  What ignition timing are you running? The engine will live a LOT LONGER if you can keep the mixture under 13.5:1.  What fuel are you running?  Any detonation at that compression ratio running that lean will torch the head gasket in no time. 

[kuroneko]

Thanks for the input so far. I appreciate it and agree with everything.  From the lean-ness to the carb size (45 vs 48).  Yes, it's a race car, not a street car.  Aside from initial shakedown and setup day, I have one race weekend in the car.  It's a lot of fun.   Now...I don't actually think the car is running as lean as the dyno info I posted.  The car has an EGT gauge in it wouldn't indicate it was running THAT lean. Neither would spark plugs.  But I don't know and haven't had it on a dyno to know for sure.  Lack of that information I made an effort to be gentle with it so far.  I've also been running VP 1100 and CR14 through it as well, which the later is massive overkill.  Max timing is 31 degress at 5,000 rpm.  I've also replace the side pipe exhaust with a full run and maybe that helps a bit.  Not sure. I  just need to get it on a dyno see with my own eyes.  

 

I'll take the suggestion about the E tubes.   Maybe it might be best to size everything down rather than working backwards.  So that is why I was wondering what a good base setup might but.   I know enough about DCOE to be dangerous...and maybe that's being generous! 

Edited October 5, 2016 by kuroneko

[kuroneko]

And I actually haven't pulled any of the jets to confirm the setup, but I have no reason to believe it wrong.  Probably should do that............

[kuroneko]

16 minutes ago, Preyupy said:

I have a number of 2 liter engines with 336 cams and 12-13:1 compression ratios out in the vintage racing world and your jetting is not far off, most of them are running 40mm chokes in 45DCOEs and depending on the header and air cleaner 165-175 main jets are normal and 155-175 air correctors are in the range.  Most of them run either the F16 or F2 E-tubes.  What ignition timing are you running? The engine will live a LOT LONGER if you can keep the mixture under 13.5:1.  What fuel are you running?  Any detonation at that compression ratio running that lean will torch the head gasket in no time. 

 

And Preyupy, looks like you are in NW.  If you run SOVREN, you'll probably know the car.  Jack Healy's 2002 which I acquired early spring.  Built by Racecraft, Terry Tinney motor.

Edited October 5, 2016 by kuroneko

[TobyB]

Oh, heck- I hereby defer to Byron on this one- that's a nice car.

(interesting that 4mm in choke makes that much difference in jetting.  But it make sense)

 

And you should call both Terry Tinney and Terry Forland. 

 

t

 

 

Edited October 7, 2016 by TobyB

[Preyupy]

I do know the car, Terry Tinney built a great engine for Jack I would check your AFR data, unless someone has changed the jetting since he had it in the dyno there is no reason it should be wrong. 

 

The fact act that it is leanest right at Max Torque ( 336 cams usually make max torque somewhere close to 6900) means you are very close on jetting. 

Edited October 6, 2016 by Preyupy

[kuroneko]

Yes, max torque is almost dead on 6900.  I spoke to Terry via email very very briefly trying to get more info & specs on the engine.  He was accommodating but I'm guessing busy with paying customers.  Same thing with RaceCraft.  I dealt with Jim at RaceCraft when buying the car.  They seem like great guys and great shop.  But it's not their car to deal with anymore so I can't expect too much.    Ray Korman was also surprisingly approachable and helpful too when asking about top end components.  But again, he too was going at it as if they would do the work.   I try to respect everyone's time, particularly if I'm not necessarily going to use their business or products.  Not be a time vampire.....  That's what online forums & communities are for!!!!

 

 

Edited October 6, 2016 by kuroneko

[TobyB]

Well... yeah, but the quality of the advice is umm... errr....  but, I, errr...

well, Byron did chime in, I guess!!

 

hee

 

I don't think you're pushing your luck too much to get specs from Terry.

But you're right, respect is important. 

t