Bigger Bore Etc

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Ace VenTRa
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Re: Bigger Bore Etc

Post by Ace VenTRa »

And here she is well under way again. The balanced assembly is back together and in the block with the 99mm JE's, happy as a clam. Everything is back from cryo treatment and the pistons have their ceramic coating on top for good measure. The RC trans is coming along nicely and I'm just waiting on some circlips and a gear that is being back cut. There is a noticeable difference in the ease of assembly with polished journals and resized rods, it was smooth as butter on the last build but this one takes the cake...
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sirch345
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Re: Bigger Bore Etc

Post by sirch345 »

Good to hear of your further progress, it's all looking great :clap:

Chris.
Dickiebig
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Re: Bigger Bore Etc

Post by Dickiebig »

Superb, only wish I had your skills and confidence. Well done that man
tony.mon
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Re: Bigger Bore Etc

Post by tony.mon »

Well done so far, hope the build goes smoothly, and I'm looking forward to hearing it run🤗
It's not falling off, it's an upgrade opportunity.
Ace VenTRa
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Re: Bigger Bore Etc

Post by Ace VenTRa »

Cheers! It is coming along, I can't wait to fire it up with the high compression....

AV
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sirch345
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Re: Bigger Bore Etc

Post by sirch345 »

Ace VenTRa wrote: Thu Sep 03, 2020 11:58 pm Cheers! It is coming along, I can't wait to fire it up with the high compression....

AV
I bet you can't wait :D

Chris.
Ace VenTRa
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Re: Bigger Bore Etc

Post by Ace VenTRa »

No joke, I'm salivating at the thought. But, I noticed today that I managed to complete an entire season of riding without breaking anything....So, I thought I might let it go for one more before I pull the motor. I added the delwood stacks a K&N and for kicks I added a dynojet kit that I had laying around and...a home made flow control for the main air bleed and it really woke things up. At the last run I made a whopping 73.8 lb/ft of torque but only 106 or so HP. All gains are after 5k rpm and I lost nothing below that. I suspect there is a bit more in there I just need to get back on the dyno one more time. So, I am quite happy with it but seeing as how I have the CBR almost back together, I think I'll wait till it is completely track ready before I yank the motor out of the V. Essentially I have the short block complete I just need to swap the heads and peripheral stuff and she'll be ready to go!

AV
tony.mon
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Re: Bigger Bore Etc

Post by tony.mon »

And in the meantime you can still look at the tops of the high comps and rub your thighs in a Vic Reevesy sort of way.

Once the heads are on you can't gloat over them any more.
It's not falling off, it's an upgrade opportunity.
Ace VenTRa
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Re: Bigger Bore Etc

Post by Ace VenTRa »

Just a quick update on all that has transpired:

I have not had much time to get back on the dyno so I suspect that it will have to wait until spring. No big deal. The delwood stacks are a real nice addition and work quite well with a flow control and a DJ kit, it is definitely worth getting a set of non oem stacks if you intend to use a DJ kit. Anyway, here's few more pics of the motor, I's as far as I'm going to take it with new parts other than a set of head gaskets, everything else will come off the motor currently in the bike. Interesting note... The shift shaft is yet another part off the RC51 that works with the VTR, at least internally. The part that extends into the case is the only part in question. The return spring however, has one more coil! I'm guessing this gives us a better return feel in between shifts...I will find out and report back as always. Anyway, here's some more porn with a quick vid of the CBR which is well underway and ready for the track now too!

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VTRimanta
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Re: Bigger Bore Etc

Post by VTRimanta »

Wow, that looks very nice! I hope you don't mind me asking some question regarding your builds, since I have the intentions on rebuilding my own next year! :)

Do you know by any chance which material is used for cylinders? It looks like most of the times people are saying that its "nikasil" coating, which you cannot bore, the only option would be to recoat the cylinder, yet honda offers .25 and .50 oversize service pistons and rings, which makes no sense if cylinders are "nikasil". Manual doesn't have any info on materials. You said that your cylinders were bored, which makes me come to a conclusion that this engine has "alusil" for cylinders. Or did you have your engine resleeved actually?

I assume those JE pistons are a custom order. Which coating did they use? As far as I am concerned, pistons for alusil cylinder have to be iron coated.

What is your piston to cylinder clearance?

Which oil did you use for the run-in period? (viscosity, mineral or synthetic)

Did you face any major problems with fuel adjustment, considering increased compression? What exactly has been made (like dellwood stacks, needle adjustment, jets, A/F ratio screw). At this moment I am not sure if I wan't to run with JE pistons, maybe just go with the honda stuff.

Thanks in advance! looking forward seeing the finished result with the engine running! :beer:
tony.mon
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Re: Bigger Bore Etc

Post by tony.mon »

There's no coating on the bores. They're iron, so can be bored then honed to an oversize. There's no trick coating on the pistons, either, aluminium alloy.
Piston to bore clearance should be as the Haynes manual, similarly ring end gaps.
Ordinary 10/40 semi synth is fine, change after 2-300 moderate miles, but don't go too easy on it.

Like all storms, you can't just copy someone else's setup, set your own engine up properly and don't try to take shortcuts.
There are too many variables, what cans, how much wear in the carbs, etc, etc.
It's not falling off, it's an upgrade opportunity.
Ace VenTRa
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Re: Bigger Bore Etc

Post by Ace VenTRa »

Ok, so, as far as the bore goes they are not coated in any way. They are an iron sleeve that is cast in place and could be bored out for a new sleeve but I think it would be a lot of effort without much gain. The bore is 1mm OS at 99mm and the pistons from JE are the same as they offer in the catalog, I just asked them to make them 1mm bigger. They were happy to do so.

The coating on the skirt is a proprietary coating from JE that I'm sure is some kind of Moly coating, maybe they spec it out on the web site but I haven't checked. The coating on the tops is another proprietary thermal coating from a different vendor that I use for cryo treatment, coatings, any engineering issues or theoretical problems that arise. JE also offers a thermal coating for the tops and it's basically a standard option at this point but it is not the same as what I have. If you want what I have I can point you in the right direction.

As for clearances...do not under any circumstances go by the factory manual or any other. The same applies to ring gap. The reason for this is that the JE pistons are forged and require a piston to wall spec that JE will provide you with but in my case I have mine set at .0025.

My ring gap is set at the recommendation by JE for a performance NA motor of .004" per inch of bore. So it would be 3.898 x .004=XXX for the top ring. If you want to run boost, nitrous etc you will need to open them up more.

As for break in oil I run a cheap non detergent oil for the first start and warm up session where I check for leaks etc. After that I drain it and change the filter and run Ams-oil or Driven break in oil for 500 miles. After that I run Castrol 20w50 non synthetic for 1500 or so. After that you can run whatever you want but I run Alisyn less than Zero. Most important on the break-in period is medium to hard acceleration followed by long engine breaking. This is the only way to seat the rings properly and is likely the most important part regardless of what oil you choose.

Air fuel adjustment is the same pain in the Axx it always was but what made it easier was, by far, adding a flow control. This simply ties together the main air jets to a common point and allows you to richen or lean on the fly if necessary. Don't spend the money on the commercially available ones, my kit is less than 40$ and takes an hour to install. The jetting is a DynoJet kit which works very well with Dellwood stacks and a K&N filter. Main jets are 190/195, 4th clip and 45 pilots with the screws 2 turns out. But, this is for the motor in the bike now which has a 98.5mm bore with OEM pistons set at .002" bore. I also use a reground cam that is a very nice street cam which really makes a lot of top end power without and loss in torque.

As for JE vs Honda...it's the same price at the end of the day so I would recommend using the JE. At least you will get coatings on the tops and skirts as well as a very nicely machined component and 11.5:1 compression as opposed to the lame 9.4:1 static compression Honda offers. On that note with the JE setup you will need slightly bigger main jets, may 1 or 2 sizes. I suspect a 195/200 would work just fine.

You can copy this setup and achieve the same results as me which is an excellent running machine that starts easy gets good mileage and makes very usable real world power without headaches.

AV
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8541Hawk
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Re: Bigger Bore Etc

Post by 8541Hawk »

Ace VenTRa wrote: Fri Jan 01, 2021 7:55 pm Air fuel adjustment is the same pain in the Axx it always was but what made it easier was, by far, adding a flow control. This simply ties together the main air jets to a common point and allows you to richen or lean on the fly if necessary. Don't spend the money on the commercially available ones, my kit is less than 40$ and takes an hour to install.
Well I do believe you have missed one of the important parts of the set up on this type of system.

I also believe there is a bit more engineering involved than just throwing a needle valve in there.

Being able to adjust the mixture is actually a side benefit of a flo-commander. What the main purpose of one is to provide a smooth, constant signal to the air bleeds. This gives a more consistent A\F ratio.

On yours, the Tee is right between the carbs. Which means the air flow is constantly switching directions to feed each carb. I would believe this would actually add turbulence to the signal the air bleeds are seeing.

I would suggest putting the tee fitting right after the needle valve if you wish to run this set up.

As for the comment on more engineering. I do know that there are different flo-commanders for different applications (that is why they are color coded for flow rate).

Also I may be biased but I do really like the 2 flo-commanders I am running (though it does make the airbox a little busy.....lol) :thumbup:
Loud pipes don't save lives, knowing how to ride your bike will save your life.
Ace VenTRa
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Re: Bigger Bore Etc

Post by Ace VenTRa »

I'm sure the flow commander is a nice piece, but I know mine works and it's cheap. For me...nuff said.

AV
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