Racer X engine build thread

[k-os]

Originally Posted by choneofakind

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

So did you have to buy new pistons also?

Yes and yes.

[Skippii]

Originally Posted by Racer x

basically stock with JE pistons.

Originally Posted by Racer x

I will have to wait a couple weeks to order pistons.

Originally Posted by Racer x

I have to order pistons next.

Originally Posted by Racer x

I need to order the 64mm pistons.

Originally Posted by Racer x

JE says that you don't need to balance even for the big bore pistons.

Originally Posted by choneofakind

So did you have to buy new pistons also?

I'm going to guess.....YES.

[choneofakind]

No I get that he got new pistons, I just didn't know if they were for this engine. hahaha

what I was asking is where the new pistons because of the bore? he said he was already running 13.5:1 pistons. I was confused that's all. Nevermind

[Racer x]

Just got off the dyno . I wanted to break in the new engine. I did not get any great high RPM power numbers. I was using pump gas and had the ignition timing set to the stock setting of 35 deg. With better gas I run 42 deg and that ups the power a lot.
I had 128 jets in the CR carbs and they are just a little to rich.Great for break in, But not going to make max power. I only have 122 in my kit,SO I will be ordering new jets.

We did not take the engine past 10000 rpm But the numbers looked good considering. The engine with 265cc on pump gas and stock timing was making 30+hp at 10000 rpm. with 4500 more RPM and proper jetting I can see 35+ hp from the bore up .

This is a quick video of the bike on the dyno. I don't know why I did not shoot more.
http://youtu.be/K4UUnKPZM58

[choneofakind]

I really like all your polished aluminum parts. Do you ride that bike daily? That is also one of the best looking Cafe racer/nakes style 250's (now a 265 I guess ) I've ever seen.

[alex.s]

BRB, changing my underpants. because i just shat myself.

[alex.s]

So.... when can we buy DHR engines?

[Racer x]

Originally Posted by choneofakind

I really like all your polished aluminum parts. Do you ride that bike daily? That is also one of the best looking Cafe racer/nakes style 250's (now a 265 I guess ) I've ever seen.

Thanks But with no front brakes and no tread not to mention lights . No I don't ride every day , But I do work on the bike every day,

[choneofakind]

Oh I didn't even notice those were missing.

So was the cool paintjob and cafe racer tail just for fun then?

[Racer x]

No the rear seat is part of a bigger fairing I will make after I extend the swing arm. For the 2012 season I am just working on the engine stuff. But I do have a front fairing in the works that will be fun and functional. Watch my blog.

[icbm]

Originally Posted by Racer x

Thanks But with no front brakes and no tread not to mention lights . No I don't ride every day , But I do work on the bike every day,

Slicks are notorious for not allowing a bike to show more true HP. On a small bike like yours though and small slick, I wouldn't know how much. Maybe no loss at all. I do know that on a 200hp Hayabusa I have seen a 10hp difference between a slick and a good street tire. On my bike I saw about the same and it made 215hp on Nitrous with a street tire and on a Shinko 003 Ultra only 204hp.

That bike is going to rip.

[Tony B]

Eric, I take it the ignition set-up isn't stock, as the timing isn't adjustable on the stock bikes, no ?

[Racer x]

I use the BRT TIs ignition system from Sportisi. I have used it for four years . IT is the best thing you can do to a 250 ninja.

[wayanlam]

what timing do you use through out your rpm range in the aggressive setting by the way?

would you mind posting the timing deg. for each rpm step?

id like to compare it with what i have set on mine, lol~

thanks

[Scattcatt]

Do you have knock sensors installed or anything?

[wayanlam]

knock-knock~

whose there?

the piston head!

----------

i have a built in sensor in my head, i call them my ears

they do have their faults/glitches tho... i call it human error :P

[Scattcatt]

Originally Posted by wayanlam

knock-knock~

whose there?

the piston head!

----------

i have a built in sensor in my head, i call them my ears

they do have their faults/glitches tho... i call it human error :P

I should have clarified, my question was mostly aimed at Racerx... But nice to know anyway!

[wayanlam]

i know - i know, i was just in the mood to make a joke out of it

[Racer x]

I run 110 octane fuel. My timing will vary from 35 to as much as 44 deg. No knock sensor. If it knocks I can't miss it in first gear.
With 12.5 to 1 the bike will run great on pump gas and stock timing.

[Somchai]

Eric did you ever think about installing an electric water pump for getting better power?
Maybe you'll take a look: http://www.daviescraig.com.au/Electr...5-details.aspx

[Racer x]

I have given it some thought. But there are so many other things I have not looked into it much.
Thanks for the link . Every little bit helps. I think that one is a little large with a 51mm pipe. But maybe they make a smaller one

[Racer x]

Bringing back this thread.
I am starting on another engine. This is going to be a big 265cc nitrous engine. With 12.5 to 1 JE pistons and a 4mm over bore. It will be ported and polished. Looking for 100 hp. But we will see if I can get anywhere near that mark.

For the head I am going with a stock head I bought on eBay for 50 dollars. That takes care of the broken cam and burned seat from the original engine.

I took the engine apart last year . Cleaned and checked everything. And put the bottom end together. That part is done.

I have the block bored out 4mm and i removed .010 from the top of the block. That work is already done. I just need to get to work on the head.

First I am using this engine for a big nitrous shot so I need to polish the piston tops and the combustion chamber. And open up the exhaust ports as much as I can. Also I am going to really clean up the combustion chamber to remove all sharp edges. I will post photos as I go.

[TheDementedDrummer]

What fuel will it run?

[Racer x]

VP 110 gasoline.

[Racer x]

I started on the head.
I really don't feel like I know what I am doing. But I read enough to get in trouble. So dont try this at home until I se how it all works.
It is still very ruff. But what I am trying to do is remove all the lumps around the valves. This will allow air to move freely in and out.

Also I want to remove the sharp edges that can lead to detonation or preignition. In the end the chamber should look like a bowl shaped mirror. I will just clean up the intake runners and I will enlarge the exhaust ports to fit my exhaust. With nitrous it is all about the exhaust. I am going to look into using intake valves for the exhaust. That way I can use stock springs.

engine 3 head 004.jpg engine 3 head 006.jpg engine 3 head 008.jpg engine 3 head 009.jpg

[EMSRacer07]

Originally Posted by Racer x

I started on the head.
I really don't feel like I know what I am doing. But I read enough to get in trouble. So dont try this at home until I se how it all works.
It is still very ruff. But what I am trying to do is remove all the lumps around the valves. This will allow air to move freely in and out.

Also I want to remove the sharp edges that can lead to detonation or preignition. In the end the chamber should look like a bowl shaped mirror. I will just clean up the intake runners and I will enlarge the exhaust ports to fit my exhaust. With nitrous it is all about the exhaust. I am going to look into using intake valves for the exhaust. That way I can use stock springs.

just be careful not to cut into the face where the valve touches or it wont seal right. also be careful of water jackets and oil, etc.

[Racer x]

Thanks . I have all the tools to cut the seats. I can't do anything but replace valves if they are damaged. But new valves on fresh seats seals well. I vacuum test the seal when I am done.
What I have to be careful of it hitting the head surface. That is why I cover it with tape

[EMSRacer07]

Originally Posted by Racer x

Thanks . I have all the tools to cut the seats. I can't do anything but replace valves if they are damaged. But new valves on fresh seats seals well. I vacuum test the seal when I am done.
What I have to be careful of it hitting the head surface. That is why I cover it with tape

let me know what approach you are taking with the porting. I got a head coming my way too and going to port and polish as well. Would like to know how much material i have to play with and angles too.

[tubarney]

Originally Posted by EMSRacer07

let me know what approach you are taking with the porting. I got a head coming my way too and going to port and polish as well. Would like to know how much material i have to play with and angles too.

Im getting mine done by a professional with a flow bench in 2 days, it will be ready on 1st February. Takes a week. I will take photo's of my head before and after and ask him which areas he concentrated his work to help you out. btw im getting a full race port job, not just a clean up.

Also, don't polish your head, they don't do that anymore since the flow bench was invented. Read this, these guys have been around since 1972, their doing my head.

http://www.ramsheadservice.com.au/su...id=18&cat_id=8

[TheDementedDrummer]

Originally Posted by Racer x

VP 110 gasoline.

Gave up on the E85?

[tubarney]

When you install these J&E pistons Racerx, do you get your engine balanced or do you just plug them in and go.

[allanoue]

Originally Posted by TheDementedDrummer

Gave up on the E85?

Post #33

[TheDementedDrummer]

Originally Posted by allanoue

Post #33

Oops, my bad

[Racer x]

Yes I have to wait for fuel injection. I tried everything to get enough flow through the carbs. They sell an alcohol kit for the carbs. But I need more through the mains. I will get back to it.
I don't balance the assembly's with the 265 kit. The pistons are a little heavy. But don't make any vibration at 13000.
That is a good article. I only polish the combustion chamber and piston. I need to remove hot spots. I remove the ridges and sharp edges.also deshrouding the valves. I would love photos of your pro built head. I will clean up the intake ports and open the exhaust to flow it with the header
I have an engine being built by a professional with a flow bench. I just want to see how this goes. The pro built motor will not use nitrous.

[tubarney]

Originally Posted by Racer x

Yes I have to wait for fuel injection. I tried everything to get enough flow through the carbs. They sell an alcohol kit for the carbs. But I need more through the mains. I will get back to it.
I don't balance the assembly's with the 265 kit. The pistons are a little heavy. But don't make any vibration at 13000.
That is a good article. I only polish the combustion chamber and piston. I need to remove hot spots. I remove the ridges and sharp edges.also deshrouding the valves. I would love photos of your pro built head. I will clean up the intake ports and open the exhaust to flow it with the header
I have an engine being built by a professional with a flow bench. I just want to see how this goes. The pro built motor will not use nitrous.

Interesting, if your 265cc pistons work fine i might have to look into a bore up or even a rise in compression. I've been avoiding it because of the expense of getting things balanced. Do you know how much a 13:1 stock bore piston would get on the dyno compared to stock.

I was going to do a home port job, but decided on the professional job to maximise gains, plus I dont want to f*** it. If I had multiple cylinder heads like yourself I would definitely give it a go. Will try and take some good photos for you. The wait is killing me. Should have them up by next week.

Whats weird about that article is where I found it. On a website for a tiny engine builder. Barely fit 2 cars in their warehouse. Everything I read previously said to polish your ports. Just goes to show that most pro's dont give their secrets out.

[subxero]

Originally Posted by tubarney

Im getting mine done by a professional with a flow bench in 2 days, it will be ready on 1st February. Takes a week. I will take photo's of my head before and after and ask him which areas he concentrated his work to help you out. btw im getting a full race port job, not just a clean up.

Also, don't polish your head, they don't do that anymore since the flow bench was invented. Read this, these guys have been around since 1972, their doing my head.

http://www.ramsheadservice.com.au/su...id=18&cat_id=8

Pretty sure it is the same idea as dimples on a golfball, air flows easily over itself. I know that Sharks use similar design with their "scales" Studies have shown that their "scales" trap little pockets of water and create this tumbling type effect that decreases resistance while swimming. Humans have been trying to transfer this over to body suits, and swim caps to gain the edge in water sports.

[Racer x]

Dremel makes a polishing wheel like a scuff pad. It is the perfect size to put the swearl pattern in the ports. Enlarging ports has also come into question. Seems you get more air fuel mix in the cylinder from high speed air through a small hole then when you in enlarge the hole. The air slows down with the larger port and less volume gets past the valve

[subxero]

Originally Posted by Racer x

Dremel makes a polishing wheel like a scuff pad. It is the perfect size to put the swearl pattern in the ports. Enlarging ports has also come into question. Seems you get more air fuel mix in the cylinder from high speed air through a small hole then when you in enlarge the hole. The air slows down with the larger port and less volume gets past the valve

Interesting, is there a way to increase the port size but then pressurize the air or something of that nature? Obviously like you mentioned earlier for fuel, get a fuel pump, but for air?

[choneofakind]

Ram air intake.

[Racer x]

There was a guy at Bonneville that had a Harley Davidson streamliner. He has a duct to a tube going to a plenum on the carb intake. He said he got 4psi at 120mph. Yes it works but you won't see the benefit untill you go 120.