Topic: Turbo stroker

[EnginebyAdam]

I have been digging through the site and have found lots of inspiration. Very nice work being done.

I came across a lot of guys building turbo bikes, voxonda, BLUE71TURBO, orkid1989, HavocTurbo, Bamboozler, 76kcafe, and UKCB750CAFERACERS so far at least. Very good information there. The log style seems to be the common choice for intake. I liked the SU carb and center mount of the turbo on BLUE71TURBO's bike. Hopefully some of these guys will jump in on this.

I was thinking a tubular intake with equal length runners could work. We are making the frame so clearance would be made.

Here is the links on the turbo builds I have found. Great info:
http://forums.sohc4.net/index.php?topic=56783.msg612975#msg612975 BLUE71TURBO's
http://forums.sohc4.net/index.php?topic=86708.msg975134#msg975134 orkid1989's
http://forums.sohc4.net/index.php?topic=58771.msg637133#msg637133 HavocTurbo/Bamboozler's
http://forums.sohc4.net/index.php?topic=92049.msg1027467#msg1027467 76kcafe's
http://forums.sohc4.net/index.php?topic=7585.msg69178#msg69178 UKCB750CAFERACERS's

I know the stroker would limit rpm range so that's why I'm thinking I could build a 888cc, with the 836cc turbo pistons from dynoman to keep it as light as possible plus balance/lighting crank and rods. The turbo should help pick up from the grunt of the stroker and give good top end.
 
Turbo's are not my strong suit but I'm thinking the T2 and T3's the rest of the guys are using are pretty close size wise to what I am looking for. I'm not sure as to where I would want the turbo to build boost but launching would be at 6000rpm or close to that I would say. I know I also need a ignition retard, will have to dig into that, suggestions would be awesome

What is the practical limit on copper gaskets boost wise? I want to be able to run what ever the internals can handle when need be. I am still looking for a mid ten's bike but be able to get lower with an adjustment. In all reality we are racing against ourselves, I just want to be able to mess with the crotch rockets as much as possible They usually only run mid tens so.....

We are looking at getting good at the low 12's for technique wise. Move to the 11's to see wither my co builder or I should be lead rider. Then the 10's for the duration. This gives me a lot of time for tuning.

I'm thinking this makes sense for us,  a lot more work but it will be a more competitive bike on the top end I would think.

Cheers

[jweeks]

     Copper wire o-ring the head. Copper Gaskets Unlimited did my 1080 motor head gasket. (US)
 
     I don't understand the stroker limiting rpms comment. The air flow limits rpm. A 900F (Bol D'or) crank gets you a plus 6mm stroke. APE can weld a stock crank for a +5mm increase in stroke. Either one will rev to the top of your powerband. The 900F crank is heavier than the stock one, so your revs are marginally slower. I do about a 10,500 rpm shift on my motor with the +6mm crank. The power is falling off by then. With everything balanced correctly, the crank is the least of your worries. An air cooled motor with a lot of boost needs to stay a little on the rich side. It should be towed back from the end of the track. Oil temperatures need to be monitored. General rule of thumb is that you open up the piston to wall clearances as the planned boost goes up.

     One of the greatest challenges is leaving the line with boost. Cars (Pro Mod's) in the US use an ignition timing retard when on the starting line. The motors fart and make unusual noises, but it builds boost rapidly. Leave the starting line and the timing goes back to normal as the 2 step gets released. MSD MC-4 is what I'd be using. Just my opinions.

                                                         Jon Weeks

[EnginebyAdam]

I just looked up the company you mentioned, looks like they have great gaskets. http://www.coppergaskets.us/MCG.html I'm not clear on the copper wire o-ring part, but I'll look into it. Would I need copper base gaskets as well?

I guess the point I was trying to make is that typically a stroker engine does not get revved like a stock stroke, balanced/lightened, rotating assembly. Even if the stroker rotating assembly is balanced and lightened as well. I am very glad to hear that I will be able to wind these out some. 10,500 rpm and still breathing through the head, that's the goal right there.

 

[dragracer]

I had Cometic to make my copper base and head gaskets for my 72mm motor. They can make them in whatever thickness you need.

[Jim F]

as far as the ignition systems, You can use a Dyna 2000 with a boost sensor that will automatically take out some timing
but I am not sure as to how much it will take out when the boost kicks in.
 I use a MSD MC-4 system that you can program with custom retard curves and take out lets say
1 degree of timing per 1 Lb of boost and adjust from there
with my turbo system I am going to start at 2 degrees of timing per 1lb of boost and keep it safe.
I have talked to some turbo racers and they typicly back out about 1 degree of timing on there race bikes
but mine is for the street............
If you want you can look at my build on this forum
http://forums.sohc4.net/index.php?topic=101267.0
good luck and start sending pictures please
PS. I use  the MLS Gaskets (Base and head)

[EnginebyAdam]

Jim F I have no idea how I missed your build. Sorry bout that, I'll have to dig into this tonight after I do some paying research Have to pay for all the trick parts somehow

I have dealt with Cometic before on custom stuff and the price was good so I'll have to contact them once I get my figures. Will also talk to Copper Gaskets Unlimited as well for good measure.

I use the Dyna 2000 on my current dohc ride but have not done enough testing to develop custom curves. Our weather is horrible so I am limited with the pod filters on the CR31's as well as trying to keep the Dyna 2000 dry. I think I am leaning toward the MSD MC-4 all the same. MSD is what I like on the auto's, great product, very little issues I've seen.

[Jim F]

I am still learning mine and did some learning yesterday. I hooked up the lap top plugged up the lap top to the MSD box
and programed the start retard to 25 degrees but static timed it at 35 degrees.
went back in and looked at the graph for timing.  once the bike is started. (It starts very nice on 25 degrees too)
 with the start retard set at 25 you can go to the timing graph on the software from MSD and adjust from idle (Its set at 25 degrees)
then ramp it from there to your full advance setting (35 degrees static). so when at idle, my bike is running 25 degrees of timing
when I give it some throttle, from idle it to 2500 rpm, the timing ramps to 35degrees. it will take some time to figure out the system
but the more I fool around with it the more i am learning and tech support is good too but they ever told me to go in and fool around with it
not plugged up to the box but just get familiar with the software.

[EnginebyAdam]

I am still learning mine and did some learning yesterday. I hooked up the lap top plugged up the lap top to the MSD box
and programed the start retard to 25 degrees but static timed it at 35 degrees.
went back in and looked at the graph for timing.  once the bike is started. (It starts very nice on 25 degrees too)
 with the start retard set at 25 you can go to the timing graph on the software from MSD and adjust from idle (Its set at 25 degrees)
then ramp it from there to your full advance setting (35 degrees static). so when at idle, my bike is running 25 degrees of timing
when I give it some throttle, from idle it to 2500 rpm, the timing ramps to 35degrees. it will take some time to figure out the system
but the more I fool around with it the more i am learning and tech support is good too but they ever told me to go in and fool around with it
not plugged up to the box but just get familiar with the software.

Just reading your thread now. I'm guessing the 10 degrees of spread is for test purposes?

[jweeks]

No, you don't need a copper base gasket with a copper head gasket. How much boost you run will ultimately determine what you must run. MLS easy and available for moderate boost. Copper with an o-ring will seal some serious boost. The o-ring compresses the gasket right around the combustion chamber more than anywhere else. Any head gasket leakage may try for an adjacent cylinder or atmospheric vent. Lean it out and heat will melt a lot of expensive stuff. Work your way up in boost. As you increase it, note the fuel/air ratio changes. With a carb, you're very limited unless you run supplemental fuel enrichment. I'd be using fuel injection with a mega squirt if I were going for a lot of boost. First runs on the chassis dyno monitoring fuel/air ratio if you plan on keeping the parts together. Cams for boost usually are a lot milder than naturally aspired. You don't have to wring them out ultra high rpm wise to run quickly. Getting the lockup clutch right will also have it's challenges. Yes, it can be done. I wish you luck.

As always these are just my opinions. I haven't built nor plan to build a drag turbo Honda.

[Sam Green Racing]

When you can run 8.8, who needs a turbo. 

Sam.

[EnginebyAdam]

Jim F I just got through your thread, the bike is looking great. Sounds like some serious testing is coming soon, am subscribe. Good luck.

From what I have seen the log style intake seems to be the route every one goes. Do these intakes give much trouble with the outside cylinders going lean?

[dragracer]

Would have to agree with Jon Weeks on the fuel injection route. I think i read a thread here or on the chopper site about a successful throttle body swap from a GSXR600 or 1000 onto a Honda SOHC. The used a microsquirt if i remember right. The initially used the ECU to control fuel but eventually used it to do ignition as well with the proper trigger wheel set up. Mega/microquirt users are world wide and there's a ton of support available. I've seen used turbo systems in Ebay for SOHC bikes from time to time but they are rare.

[Jim F]

Jim F I just got through your thread, the bike is looking great. Sounds like some serious testing is coming soon, am subscribe. Good luck.

From what I have seen the log style intake seems to be the route every one goes. Do these intakes give much trouble with the outside cylinders going lean?

Ive got 2 other bikes up at the dyno and as soon as they are done, we can start on the turbo. I am still playing with the ignition
so anyone running one of these please chime in. I wont run boost until we get the correct air/fuel ratio and then we can start to run
boost and back out the timing
will keep you posted

[Retro Rocket]

Would have to agree with Jon Weeks on the fuel injection route. I think i read a thread here or on the chopper site about a successful throttle body swap from a GSXR600 or 1000 onto a Honda SOHC. The used a microsquirt if i remember right. The initially used the ECU to control fuel but eventually used it to do ignition as well with the proper trigger wheel set up. Mega/microquirt users are world wide and there's a ton of support available. I've seen used turbo systems in Ebay for SOHC bikes from time to time but they are rare.

I have a set of modified GSXR600 throttle bodies for a 1000cc build, apparently they will flow up to around 300HP {read that somewhere a while back} so are plenty big enough for our bikes....

[Sam Green Racing]

Very nice Mick.

Sam.

[Bill/BentON Racing]

I've got complete setup from 2008 CBR1000RR...hum? lol! Bill

[EnginebyAdam]

Edit: Will have to go blow through with the gsxr throttle bodies correct? The only fuel injection setup I have done was on a twin cam Harley so I have experience tuning that setup but it's not like I built it from scratch. I used a auto tune setup which helped a lot but I don't think that would help here.

What year would gsxr throttle bodies do I need?

[Retro Rocket]

My TB's are from a 2001 GSXR600, but they have been cut and shut to suit the Honda spacing and had the throttle linkage moved to the center so i can use stock throttle cables, it was done by a member on this forum....

[EnginebyAdam]

I found a set of pistons that match the compression height of the stock cb750 pistons pretty close. The compression height is 24.93mm vs the stock cb750 compression height of 24.36mm. Can some one else check the cb750 compression height for me?

They are 72mm, flat top 2 valve, 17mm wrist pin, pistons made by MTC. I plan on staying small bore for the turbo but came across these in my search. Could make a good low compression big bore, if that is what you want.

http://www.pitstopperformance.com/kawasaki-z1-kz900-kz1000-and-kz1100-mtc-piston-kits-c-1_4_15/mtc-k-1075cc-turbo-piston-kit-copper-head-gasket-p-54

[Big Jay]

If you go from 63 to 72 mm piston and it has the same top, you will still have a serious compression increase

[EnginebyAdam]

If you go from 63 to 72 mm piston and it has the same top, you will still have a serious compression increase

I completely agree. If I were to use this piston as a turbo piston I would have to get creative to lower the CR to a workable level. One of the things I would consider would be a machined dish in the piston. The valve reliefs may also not be ideal so fly cutting them would allow a slight drop. Nitrohunter used five base gaskets to lower his CR on a turbo build he did, so another option. For most these would not be a good choice for a turbo but if you have a good buddy with a mill and he works for beer it could happen At this bore size an off the shelf turbo piston is something I have not come across. As a big bore piston I would still consider this an option.

I mean no disrespect in any way, shape or form to yourself or your company by bringing this to the forum. I like to do things the old way if at all possible. Some times old school hot roding is a waste of time and proves nothing but I try to keep an open mind.

Adam Nichol
Engine by Adam

[NitroHunter]

If you go this route... remember I made a modified dowel pin, used inside the oil supply 'O' ring, to support the longer assembly.
There are far better options available. 

[754]

Nitro, if you did it again..do you think two gasket and a thin plate , would be better?

[EnginebyAdam]

If you go this route... remember I made a modified dowel pin, used inside the oil supply 'O' ring, to support the longer assembly.
There are far better options available. 

I'm sure there is

[NitroHunter]

Sometimes, a man's just gotta do what a man's gotta do - with what he's got.
And I REALLY wanted to go racing.
The price was right.