Racer X engine build thread

[Racer x]

I am starting on my engine builds for next year. I want to have three engines for next year.
I race land Speed and Drag racing.I use nitrous but that is not part of the engine build. Plus I am still sorting that out
These engines will be used in the same bike.

The basic set up uses a pair of CR 31 Specials and a BRT tis Ignition system. I use the dyno in sterling Virginia at RNR Cycles


The first engine is 249cc basically stock with JE pistons. 13 to 1 standard bore. The head is ported and polished .the rest is stock except for the chain tensioner .For that it has an APE chain tensioner . With the porting it made 32-35 hp on pump gas.


this is the "C" engine it was damaged in May at Maxton. and I rebuilt it for September.

this is a link to the dyno results. http://www.ninjette.org/forums/showthread.php?t=84882

I am going to test it on October 29th at Maxton. Then take it apart to see how it looks after the race.

Next is the "B" motor . It will be the same set up. But it will use the 265cc Big Bore Kit.

[Racer x]

For the "B" motor I will document the build. This is the start. I have a good bottom end and a damaged head and a damaged block .The work starts now to prep parts and start ordering stuff.

First I need ROD BOLTS. Just a note. IF you take apart a 250 ninja engine .DO NOT unbolt the rods. Unless you need to . The rod bolts are one time use and must be replaces if you loosen them. So that will be first . Gaskets, rod bolts and pistons.

[greatwhiteninja]

Originally Posted by Racer x

The head is ported and polished .

im curious is this the intake/exhaust ports, ported? or .. did you do it yourself or have a machine shop do it?

[Racer x]

I did it myself. I did more of a clean up than a port job. But I made the combustion chamber mirror finish. Deshrouding the valves a bit. I don't recommend grinding away at the head. You really need a flow bench and a guy that know how to use it. I just cleaned up the casting and polished things up.

[caliente103]

how about using extrude honed to clean up the ports http://www.extrudehone.com/auto/auto-performance.php

http://www.gethoned.com/parts.php?ge...how=motorcycle


http://www.gethoned.com/parts.php?ge...rts&show=karts

[wayanlam]

http://youtu.be/WmS9dTW-QT0

http://youtu.be/sY4nMkMe_tw

those are 2 videos of my mechanic doing a bit of a porting job~ not crazy exiting stuff, but still interesting to see~ there is a lot of labor/time put into porting the intake and exhaust. he told me it takes him about 10 hours or even more to do one engine.

cheers,
W.

[Racer x]

Nice work.
I like what he is doing. I will try to replicate it. There is a lot to porting. One thing I do is cover the gasket surface with heavy tape. Just to protect it in case I get loose with the grinder.

My head is damaged. I burned a valve. It is just a tiny mark on the valve seat. I can cut the seats. But this is to deep. I also broke a camshaft. I guess when I unbolted it I unbolted it from the chain side last , That cocked it and broke the little flange. Cams are 200 dollars each. I also need valves. SO I will look on EBay for a new used head. From there I will do a port job.
Great video..

[spicy mayo]

I have a set of cams from a cylinder head with less than 1000 miles on it if you are interested.

I also have that cylinder head as well, a screw made its way into one of the cylinders and I havent gotten around to fixing it yet, but if you could make use of it for one of your builds better that then it lying around. I also have all the springs / 6 good valves with this one.

I also have an ADDITIONAL cylinder head, this one didn't have cam holders so I never used it, and associated valves/springs/hardware.

Good luck on your builds, let me know if you need any of this stuff id be happy to sell it for a good price.

[Racer x]

I found a head on E bay . Complete so I should be good. I ordered all the gaskets and rod bolts from Cheap Cycle parts. The head is 200 bucks and the parts are 107. So far I am at 300 bucks and a pile of old stuff.

I will have to wait a couple weeks to order pistons. But I will Build up the bottom end in the mean time.

[Racer x]

this is the manual chain tensioner I like to use. 55 dollars. But it is cheap insurance that it will not slip.
I will order this next.
http://ape-store.com/shopsite/page6.html

[caliente103]

http://www.kriegercamchaintensioners.com/
Posted via Mobile Device

[caliente103]

http://www.orientexpress.com/Kawasak...ss+Pusher.html
Posted via Mobile Device

[Outlander Systems]

I want the dirt, details, and the pics of your Boss Noss setup...

[Racer x]

Well I gotta say I am not happy with the system..
I don't like to say bad things .But after a year of trying to get the system to work. I Just cant seem to get the system to deliver enough fuel. White plugs and holed pistons. But I am using the system at the extreme side of things.Maybe with less compression and not spraying as long as I do .Maybe it will work. I have decided to go with the Wizards of nitrous system for 2012. But go check out Boss Noss on You Tube. They are nice guys and the system seems like it should work.

[V2Neal]

Subscribed!

I'll be watching this as my engine will be getting a rebuild over the winter. I think two race seasons are enough.

What are you going to use for rod bolts? Factory or aftermarket?

[Racer x]

I just order parts from Cheap Cycle parts. They come in OEM bags most of the time. I just got them but have not opened the box. I also got a new head . So I will get started real soon. I have to order pistons next. But I still have to unload the van from coming back after the race. And get some money for parts.

Just opened the box. All the parts are OEM.

[pop0tart]

Hey Eric, You're listed as living in my town (Hollidaysburg, PA) on the member map. Glitch on the site? ..Or you entered your info incorrectly? ..neighbors?

[Racer x]

That's Odd I will fix it. Sorry I live in Baltimore City. I bet Hollidaysburg is nicer than Baltimore.

[pop0tart]

Every day's a holiday here..

[Racer x]

ya That is what I thought. BUT how do I change my location on the member map?

[pop0tart]

long process...easier to just pack your **** and move here



Ask Alex?

[Racer x]

Getting things started. I have a lot of parts. And I did not do much damage to the bike racing September and October. I pulled it down and only found a burned exhaust valve.

I can do most valve work myself. I went to Goodson Machine and bought the tools to cut the valve seats. I don't do much cutting .Just clean off the burned valve or piston material. Once the valve seat is cleaned up and the head is already. I use NEW valves . I don't cut or clean up old valves.I am very afraid of breaking a valve at 14000 RPM. that would ruin my day.

I use normal grinder and sander bits to port the head. And I don't do much of that either, I do spend a lot of time polishing the head. That is to help prevent preignition.

I need to order the 64mm pistons.But have not decided on the compression ratio, And I don't have 700 dollars to spend. So in the mean time I am going to work on the heads and put the bottom end together on the "C" motor.
So far I am still at 300 dollars on the spendometer and I have enough parts to build two engines.

[choneofakind]

Originally Posted by Racer x

ya That is what I thought. BUT how do I change my location on the member map?

Add yourself a second time in the correct location, and pm alex and he will go delete your first one. At least I think that's what the directions were.

[Racer x]

We got it sorted. Alex is on top of things.

[wayanlam]

hi Eric,

realized that you would be the right person to ask;

so i changed my pistons to the 265cc, 12.5:1 compression from JE.

since ive changed them, i notice a stronger vibration when i go over 8~9k rpm.

below that rpm the bike actually drives as smooth as it was in the past. but passed that rpm i am quite sure that it is vibrating stronger, i feel it on my legs that rest on the fuel tank, my hands on the grips, and fingers on the levers and generally everywhere, lol!

ive asked the mechanic about it, and he said that because of the increased piston weight combined with increased compression, etc. it causes the added vibrations.

i am aware that you were running stock bore pistons in the past, but did you notice any increased vibrations between stock pistons, and the high compression JE pistons?

im contemplating to get them to take the engine apart again, to double check that everything is in working condition in there, before any catastrophic failures occur, lol

ive noticed that the exhaust sound is also a little different, but im assuming that would probably be from the higher compression ignition~

cheers,
W.

[pop0tart]

Originally Posted by Racer x

So far I am still at 300 dollars on the spendometer and I have enough parts to build two engines.

Looks like you have a very nice shop set up. Would you consider converting a few more for fellow racers?

[caliente103]

Originally Posted by pop0tart

Looks like you have a very nice shop set up. Would you consider converting a few more for fellow racers?

+1

[Racer x]

I wish I had time. It will be all I can do to get these going by April

[Racer x]

I got the bottom end for the "C" motor together. Some how I lost the woodruff key from the crank. I must have put it some where. The next small parts order will have to go out soon. I need the gaskets and valves anyhow. That should be under 150 dollars.

[Racer x]

I ordered the parts from Cheap Cycle parts. Another 162 dollars. So far I spent 200 on a complete head. 150 on gaskets and rod bolts. and another 162 on valves and gaskets.

That is 512 dollars to repair two engines. Now I need to order one set of pistons. That way I can send the blocks to be bored to 64mm. I will have to wait a bit for that. SO now I will concentrate on the head work


First thing to do is strip the E bay head and clean up the casting . Then polish the head in the combustion chamber to a mirror finish.After that I will clean up the valve seats and lap the valves. once all that is done I can reassemble the head and adjust the valves.
Stay tuned ... This will take some time . I will post up some photos.

[wayanlam]

have you ever recorded the work you do on the heads to polish them?

just wondering, since i would like to show it to my mechanic and ask him if he can do the same~

W.

[Tony B]

Wayan, if the pistons are a different weight to the originals, it may be worth getting the crank dynamically balanced.

Eric, what is the purpose of the flange on the cam, I have one with damage too, and not sure if I need to change it. (not on the bike I'm using I hasten to add !).

[Racer x]

I think the cam flange is like a thrust surface. I would not use a broken cam.

You can get the crank balanced,I talked to the balancing guys. They need 3/4 inch bearing width to get the "Bag" on the throw. What they do is weigh your piston and rod. Then fill a bag with that weight of shot and balance the crank.

JE says that you don't need to balance even for the big bore pistons. BUT we will see. I am going to build the "C" engine and see if it is OK. Then I will have the "B" engine balanced if need be.
The "A" engine will be balanced because of the different rods and the A motor will be special.

I have the bottom ends together at this point and am going to work on the heads while I save up for pistons. The first thing I do is strip and organize the head parts.
I do not want to mix up the cam buckets. The are worn in to the cam and I don't want to change anything.

I use a simple valve spring compressor from EBay .It cost 50 or 75 dollars. Before I do anything I cover the head with heavy duct tape. That will protect the head gasket surface while I work.

Once everything is apart and clean I will organize the tools and work area. I will only be doing a small amount of clean up on the "C" head. The "B" head will get the full port and polish treatment.

[Racer x]

With the head apart I repaired the damage from October

I use a dremel tool and sand paper. Sanding and grinding .Being careful and stopping a lot and coming back to it. . Now I am ready to lap in the valves, I use new valves and lapping compound,

Then to test the seal of the valves I have a vacuum pump. It has a small suction cup I can attach to a hose. With this I can test the seal and see if it holds. It will show up quick if there is any leakage.

[almost40]

what happend to this thread?? You still building racerx??

[Racer x]

Just wanted to reserect this thread. I have been working on the bike. The C engine is done. Nothing fancy just a strength up 4mm bore up and a little head work. The engine started right up and has about 180 psi cold compression. On Tuesday I will be in Sterling Virginia at RnR cycles to break it in on the dyno.

[choneofakind]

How much power does a 4mm bore gain you?

[alex.s]

im more curious about how many CCs that makes each cyl? 128?

[Racer x]

The dyno will tell how much the bore up is worth. I have had a real 34 hp with 13.5 to 1 and 249cc. I am hoping to get to 40 hp but I think 35hp all day with maybe a 36 on a couple pulls would be more realistic.
I am just breaking in the engine so I will get what I get , The real power increase will come from the nitrous.

With 4mm it comes to 265 cc so 132.5cc each side?

[choneofakind]

Dumb question here. Boring increases the diameter of the cylinder right?

So did you have to buy new pistons also?