Topic: 350f, Bonneville bound.

[MondayLSR]

Thanks for all the support guys. 

I got the motor tore down friday night.  cam journals, and the rod/main bearings/journals are in perfect shape.  looks to be a geat motor to start with.  Im still amazed that the cam journals are only "splash" lubed!  Rods actually surprised me in there size, but I'm sure the material/rod bolts arent the strongest.  Great news, there does look to be room to swing around a beefy aluminum rod in there though!

I did manage to wake up around 4am because i couldnt stop thinking/worrying about my turbo choice.  Really hope this motor can flow enough air to spool it at a respectable rpm.  I keep forgetting how small cc motor this really is.  I might look into cam options, and put some more effort into developing the ports on a flow bench.  I wont change the duration, but want to make sure I lift high enough to fully utilize the ports.  Worst case scenario, I can drop down to a gt12 if this one is too much.

I will get some pictures this week to show where Im at.

[Syscrush]

What's the record for hp out of a turbo 350?

To hit 100whp means ~120 at the crank.  120hp/0.35L = 342 hp/L.  For a 2-valve naturally aspirated engine, ~100 hp/L is definitely doable.  Doing a very naive estimation, you'd need about 2.5 bar of boost to turn that 100 hp/L into 340+, which translates to about 37psi - at altitude.

I'm not any kind of expert on this stuff, I put these numbers out there in the hopes of contributing to the conversation and hopefully being corrected/educated about where I'm wrong.

[MondayLSR]

My neon on boost only (no nitrous) made 310 hp/L@23psi. The turbo I used was very tame in the world of racing turbo 4 cylinders too. I know of a hand full of guys making 1200hp from 2.0ls!  Not sure how relative that is....

I understand your reasoning, but what a n/a motor is capable of doesn't have much to do with what a turbo version is, because two different turbos at the same psi, do not flow the same cfm.  Also, two motors, same turbo, same psi, different head ports/cam will not make the same horsepower. For example, honda motors with the popular gt35r will max out the turbo at a lower psi than a dsm motor. Both making similar numbers in the end.

I am taking some risks/guesses, but educated to an extent. I know what ~2L motors can do and with the size turbos I have seen be able to still work on them, I can assume that this 350 could turn this one over. I did do the math to lay out where this motor would sit in the compressor map, but again, not sure how relavent that is, as I have seen small displacement motors work well with turbos well out of range of what the compressor map would suggest.

I'm not positive I can make 100hp, but I think I can get close. This is a learning experience for me too, so keep this discussion going, I'm interested to hear others takes on this idea.

[MondayDad]

Don't forget that the reason that airplanes are turbocharged is to take altitude (pressure drop) out of the power equation.  With proper boost control, the engine can be as (or even more) efficient as at sea level while it moves through air with considerably less resistance (think "free-falling man exceeding the speed of sound..." recently).  Granted, we're not going that high... but 4000' will certainly affect a naturally-aspirated engine's performance, and even small airplanes do that all the time.

[Syscrush]

My neon on boost only (no nitrous) made 310 hp/L@23psi. The turbo I used was very tame in the world of racing turbo 4 cylinders too. I know of a hand full of guys making 1200hp from 2.0ls!  Not sure how relative that is....

Very cool.  Was that a 2-valve or 4-valve motor?

Do you have any concerns about trying to map those kinds of #'s to an air-cooled engine?  A big fat oil cooler might be a worthwhile idea for this project.

Also, two motors, same turbo, same psi, different head ports/cam will not make the same horsepower

For sure.  And with a 2V motor it seems to me that the risk is having a lot of boost in the intake tract due to the flow being choked down by that single intake valve per cylinder.  On the flipside, with the comparatively huge bore spacing, you might have the freedom to really open up those intake ports a lot more than you could on a more typical 4V head.

I'm not positive I can make 100hp, but I think I can get close. This is a learning experience for me too, so keep this discussion going, I'm interested to hear others takes on this idea.

I really hope you can make it! I would love to see you get there!

[MondayLSR]

Totally agree on using a big oil cooler.

Yes, all my experience has been with 4v heads, and from talking with Josh@4 piston, they are a much different beast when developing a port.  Again though, in my experience, it's amazing how much hp you can develop through a restricted cylinder head. (not that this head is, I mean it does make 100hp/L as stated which in the n/a production world, that's no joke!)

From my experience, any given turbo can move X cfm, with nothing else about the motor considered.  If you put that turbo on a 100hp/L motor it might move that same X cfm at 20psi, and be maxed out at 20psi. Put that turbo on a 50hp/L motor and it might take 35psi to move X cfm, but it will still make the same peak hp. (I say peak, because usually the largest difference is the area under the curve between the two motors, where the 50hp/L motor is very peaky in power delivery)

So while I do want to develop this head/cam to an extent, from my experience I'm not going to go too crazy doing so because I know in the end I can just turn up the boost to compensate for any lack of flow it may have. Really my biggest concern and why I might look into developing it a bit more is to try and stay away from being too peaky in power delivery, because from what I have read, putting power down on the salt is half the battle! 

[Syscrush]

From my experience, any given turbo can move X cfm, with nothing else about the motor considered.  If you put that turbo on a 100hp/L motor it might move that same X cfm at 20psi, and be maxed out at 20psi. Put that turbo on a 50hp/L motor and it might take 35psi to move X cfm, but it will still make the same peak hp. (I say peak, because usually the largest difference is the area under the curve between the two motors, where the 50hp/L motor is very peaky in power delivery)

This all makes perfect sense to me.

So while I do want to develop this head/cam to an extent, from my experience I'm not going to go too crazy doing so because I know in the end I can just turn up the boost to compensate for any lack of flow it may have.

This makese sense in theory, but the difference between this machine and a car is that if it throws a rod, you're eating salt, and if it grenades, you're picking out shrapnel.

Really my biggest concern and why I might look into developing it a bit more is to try and stay away from being too peaky in power delivery, because from what I have read, putting power down on the salt is half the battle! 

TBH, I hadn't even thought of that.  As a physics 100 problem, assuming the gearing isn't way off all you'd care about to hit a certain speed is peak hp & total drag.  As a motorcycle riding problem, it takes on some different dimensions.

[Old Scrambler]

OK.......putting power down on the salt......from my perspective, you have to work backwards.  You will have a very limited selection of tires to work with, but the narrower the better for reducing rolling resistance and areo considerations.  I run stiff suspension but some people like to be rigid at the rear.  Some years the salt is quite bumpy.....and some years or after a day or two, it gets loose and you can follow tracks.  You ride and shift real smooth like a Sunday jaunt down the back roads.....until you get wound out in 4th and make a fast shift to 5th to keep the revs up. Then you get into your best tuck before the first timing flag and hope you are up to speed.

Fender selection and design becomes quite important at speeds above 110 mph. Weight bias must be considered.....and if you really get that much power.....you may want to fill the swingarm with lead.  I would think about keeping your motor as narrow as possible. Using small twin oil-coolers along the side or at the rear may help air-flow.

If you retain the electric start......think about twin batteries......one for the ignition and one for the starter. If you going to compete in the modified class you are restricted on lowering the seat to the top of the rear rim.   

Are you running standard port angles with standard sized valves?

[MondayLSR]

Thanks for the info!  Every detail you can think of when it comes to actually going down the salt, please don't hesitate to post it.

Plan as of now is to run a 16v battery with no alternator.  Reasoning: (because I seem to keep catching flack for that idea  ),  In my experience with the neon, I kept tossing my alternator belt at a race (9600rpm will do that)  when I finally got it to stay on for a pass I gained a substantial amount of mph.  I know a 12v battery alone will be able to get me down a pass.....but a 12v system really sees 14v with a working alternator.  With all the extra electrical components I will need to run (water pump/fuel pump) Im already worried the alternator wont keep up anyway.  so 16v....yup   

Not sure what you mean by port angles, but if you mean valve angle, Im not going to even try getting into changing those!    If you just meant port design etc....the plan thus far will be to flow the stock head on a bench, then do a simple short turn port and see what that gains.  I will do some research on 2v heads, as I know there is a lot of info out there on designing these ports.  From the looks of the port though (valves arent out yet, so just a ghetto look so far) I expect to gain a fair bit from short turn alone.  I will set my valve throats dia with the valve job.

Valves will most likely be 1mm oversized, mostly because, why not if I have to get a valve made anyway. 23m exh, and 27.5mm intake (just going off #s on TTR site, since I dont have valves out yet)

speaking of TTR, I contacted him last week (or week before, they are all blending together), great guy, and amazing selection of parts on his site.  I look fowarding to placing an order with him soon.

heres a few pictures...


Pretty much how it sits right now, only difference is the motor is an empty shell in the frame for fabrication times.

Got this little cutie in the mail today!


and off topic, but im a proud dad......

My corolla and gt380 during its build

Finished gt380 with the girlfriends yas1c in the background

[MondayDad]

Just a quick update on the project. 

Matt spent much of the weekend completing disassembly of the Must-dache 1 ("MD1") bike motor.  He said that he can't wait to have everything disassembled so that he can start putting it back together.  A lot of time was spent with the parts washer trying to get carbon and long-term oil off the aluminum motor parts.  We (add one of Matt's older brothers, Jon) spent Sunday afternoon figuring out the geometry changes we want to make to the bike to further stabilize it at speed.  As some of you know, there are limits to how much the wheelbase can be increased to stay in the class we've selected.  Once those factors were determined (trig is something we never thought we'd use, right?), the frame was loaded in the trailer and delivered to the shop that will be cutting it apart and making those changes.  In the meantime, we're waiting on the metal to be delivered for fab of the intake and exhaust manifolds.

While Matt was working on disassembly and parts washing, I was trying to get Must-dache 2 ("MD2"), the back-up bike, running better than it was.  The two bikes are virtually identical even to the point of being the same color.  One is a '72, the other is a '73.  Nothing has been disassembled on it other than some external pieces (seat, carbs, etc.).  If nothing else, it gives me something to do while Matt is working on MD1. He made more progress than I did... I hate a round o-ring that is supposed to function as a weird-shaped bowl gasket!  Unscrew the bowl and SPROING!  The o-ring pops out, and it is now just a LITTLE bit longer than the slot it is supposed to fit in.  After a lot of sticky grease resulting in moderate success, I have some shape-formed o-rings on order now.  Maturally, MD1 is going to be fuel injected, so this won't be an issue on that bike.

Last but not least, brothers Tim and Dave are getting logo, FaceBook presence and an the first project video wrapped up.  We hope to get that all posted soon...

MondayDad

[MondayLSR]

I contacted ARP in hopes they would have 8x1.25 head studs for me....wrong.  Best they could do (outside of buying $800-$1000 custom studs) were 10mm studs.  After looking the block/head over, there is just no way the 10mm will fit without major modifications.  After some internet searching I came across m3racing.com.  His site showed studs for cb350(2), so I shot him an email about what Im looking for.  He was very helpful and had a few different lengths of 8x1.25 studs to offer (none perfect for what I needed, but beggers cant be choosers).  Great guy, and has been ultra helpful....even dropped one of each length in the mail for me to see what can be done! 

The ports are sad at best in stock form.  I expect substantial gains with short turn work alone.

I know I prefer pictures to text...so here are some to stare....   sorry for the quality, Im working with a 3 year old iphone thats on its last leg...and the gopro doesnt take much better still photos.



heading towards its new destiny.  I like to think that the bike found us, just as much as we found it.




Stable mates.


VZ21 turbo we were originally going to use.  Upon further inspection, it wasnt quite up to par.


VZ21 turbo compressor wheel.

[MondayLSR]

Can anyone confirm that the cb350f and cb400f share the same head studs?  The dad just came across the 400f head studs offered by APE!

the 350f studs are 8X1.25, 155mm and 120mm long, with 13mm top thread length, and 18mm bottom thread length.

[Syscrush]

heading towards its new destiny.  I like to think that the bike found us, just as much as we found it.

So romantic!

VZ21 turbo compressor wheel.

WOW! Is the turbo you went with bigger than this one, or just a different trim?

[Sam Green Racing]

Sam, where can I read up on some of your projects?

Sorry for the delay Matt, I got tied up in a drag race.

http://forums.sohc4.net/index.php?topic=31154.0

Sam.

[iomtt9]

Hi M lsr there is a difference between the studs on a 400 and a 350 but nothing you cant sort out. The 2 front middle studs are different lenghts from one engine to the other. If you bear this in mind when i go out in the cold garage again i will look and tell you which is which.
Hope this helps.
Col

[Sam Green Racing]

my cold garage. 

[MondayDad]

Sam's garage looks like he has room for more hobbies!   

[Jerry Rxman Griffin aka MuthaF'er]

Here's the best site I've used to cross reference parts.

http://www.motogrid.com/pages/OemParts?aribrand=HOM

[MondayLSR]

WOW! Is the turbo you went with bigger than this one, or just a different trim?

The new turbo is slightly bigger, but a completely different turbo all together.  the VZ21 is a chinese knock off of a IHI rh3.

Hi M lsr there is a difference between the studs on a 400 and a 350 but nothing you cant sort out. The 2 front middle studs are different lenghts from one engine to the other. If you bear this in mind when i go out in the cold garage again i will look and tell you which is which.
Hope this helps.
Col

Thanks, that does help.  I contacted TTR and APE and both said the same.  APE said they should be able to work something out for those two studs for me.  Im extremely happy that this will work out.  Now to figure out a clutch!  Anyone have a cb750 clutch assembly they want to sell?  Or any suggestions on a clutch assembly that is rather similar that has aftermarket support, that might be able to made fit?

Sam- I just went through your thread.  VERY cool!  I will be keeping an eye on it, sounded like getting a length of tarmac to run on is half your battle!  Your bike looks/sounds top notch.

[Sam Green Racing]

Matt, at the time I was blessed with the fact that I had a sanctioning body that didn't require me to make the attempt at a special event and a club that were falling over backwards in there efforts to help me.
Although that club has more or less finished and their 1.7 mile track no longer available, the sanctioning body are still behind me and the club still have a short track where I might be able to run over the flying quarter.
The bike needs just a few hundred  pounds throwing at it and we might be back in business.

If you are buying from APE, remember that Jay is the main sponsor of this forum and you can get good discounts by becoming a team APE rider.  http://www.go-teamape.com/

Sam.

[jaguar]

Ill hope on for this ride, always dreamed of running on the salts

[MondayLSR]

http://forums.sohc4.net/index.php?topic=72590.0

I found the OP from this thread searching the dyno chart thread. I was most impressed at his 85hp 450cc, and shot him a pm asking for help. There is some good info in there, as towards the end another chimes in with a turbo 400. Sounds like clutch will be my downfall if not addressed properly. Also the t25 turbo is much much bigger than my current turbo, so I feel perfectly comfortable with my choice, although now I fear it may be a bit small!

[MondayLSR]

 Took a short break to eat some turkey, but have been hard at it all week in the evenings.  Huge thanks to Ethan for helping with the frame.  We managed to get it raked and stretched, along with getting his 91 jetta running and driving on ms3.


Exhaust manifold pieces came in.


Ethan Stiles @ S&M Fab welding up the neck/extending the swing arm.


Steel to make slugs to extend the swing arm.



Still within the allowed +10% wheelbase.  Now its time to start fabbing the exhaust/intake manifolds and intercooler/piping.

[knowsnothing]

Nice, it already looks fast 

[Sam Green Racing]

What is your target speed Matt and what is the exsisting record ?

Frame is looking good.

Sam.