ENGINE WORK

[patlangan]

HI GUYS,so i have a spare engine,a zxr 400 h,im building a race bike,i have ram air etc, usural mods,im thinking of now doing some engine work,MYSELF!
im just looking for a possible list of engine work,
these are things i plan to do,if i leave anything out or put anything in that is wrong please someone correct me!

1.remove base gasket.
2.lighten con rods.
3.polish top of pistons.
4.skim .5 mm of the head,
5.polish the inside of the head?
6.set one of the cam sprockets one tooth ahead of the other.
7shave some weight from the cam shafts?
8 replace the cam chain.
service

i wil be takin it apart myself aand doin that side of things,i will be getting an engineerin company to do the shaving!
i fell confident eneough,there is a lot of info on this site!
thanks.

[Ballsout Racing]

1.remove base gasket.

Why?

2.lighten con rods.

Why?

3.polish top of pistons.

Why?

4.skim .5 mm of the head,

Why?

5.polish the inside of the head?

Why?

6.set one of the cam sprockets one tooth ahead of the other.

Why?

7shave some weight from the cam shafts?

Why?

8 replace the cam chain.

Good idea.

service

Good idea.


All my Why? questions are asked because I'm interested in where you got the ideas from and do you understand what effect they all have? There's only two things in there worth considering doing assumimg you know why and what you're trying to acheive, but even then may be uneccesary! But then what do I know, I don't tune engines myself, I leave it up to the experts

[rmkd177]

Well i do a little bit of engine tweaking....but some people write pages and pages on tuning engines...books infact
So it would take some explaining how to do it on a forum post...
But your reply is nicely set out Grev and i agree..
Just to add tho it seems 'patlangan'.......'a little knowledge is dangerous'.

[Davw]

For what its worth - my view on this is - if you are rebuilding an engine for a road bike then fine but if you are aiming to race and want the power necessary to be competetive then unless you want to learn the skills required for race engine building from the experience of mutliple engine failures then best to send the engine to a race tuner. The valve to piston clearances necessary for racing power are so close (particularly if you are skimming heads/ dropping gaskets etc etc) that unless you are knowledgable about what you are doing then you will inevitably experience engine failure. My suggestion would be to send it to Roger

[gaz9176]

I agree send your engine to roger mate he is top bloke with proven fast reliable motors, iv been in the garage for months now trying to do some of the above... there is so much to try and take in and you come across problems that you just cant get your head round. guys like roger have seen these time and time again and know ways around them. the price/time spent making and buying tools to do the jobs aint worth the hassel. tuning a motor is specialist work and should be left to those who can.... you wont learn all what they Know in a couple of weeks.. The end result will be months of your life wasted and a motor that aint as quick.

[jake]

Hey Gaz, how the injurys mate? you feeling better?
was asking paul about you t'other week. Whats the plans for this year?

[zxr500man]

go for it man ya have nothin to loose,i think paying some one else to do it would take all the fun out!!
the only way to learn how to do something is by doing it yourself!

[matthew]

"you have nothing to loose" Hmm lets see what about completely knackered engine that is only fit for the bin!!!
what about blowing the engine on the track and dropping oil everywhere,we all want to save money where possibly as racing isnt cheap as we all no however if your unsure what it is your doing-leave well alone and ring roger(RMKD) even if its just to ask his advice on something he will point you

[Davw]

go for it man ya have nothin to loose,i think paying some one else to do it would take all the fun out!!
the only way to learn how to do something is by doing it yourself!

YOu have to be joking - nothing to lose!!!!!!! how about a completely buggered engine - race engines tend to fail spectacularly if the are incorrectly set up (cost around £300 for a decent donor engine), all the time and effort spent rebuilding it (say 50 hours minimum) and the parts required, the entry fee for the race weekend and all the associated costs- followed by an engine failure during qualifying- it wont last long at 15k revs if it aint right and then the long trek home.

I reckon that if you add all this lot up that then the cost of prepping a race engine yourself when you dont know what you are doing far outweighs the cost of having it done by a pro

[jake]

plus there is nowt worse than when someones engine shites itself and spills oil half way around the track, resulting in half the race laps knocked on the head whilst they clean it up, and everyone else sitting in holding area getting very upset overheating etc....
bad enough with the sidecars

This aside, there are only so many zxr400 engines left, be kind to them

[patlangan]

I HAVE READ ALL OF YOUR REPLYS AND WANT TO THANK EVERYONE,AFTER A LOT OF THOUGHT AND QUITE A BIT OF CONCIDERATION I HAVE ALREADY MADE A START AND HOPE TO BE FINISHED IN 2 WEEKS,I HAVE A FREIND WHO WILL STICK IT ON A DYNO FOR ME,I WILL POST THE RESULTS,IM HOPING TOGET OVER 70 HP.WISH ME LUCK FELLAS,I AM VERY EXITED!!

[zimm]

I HAVE READ ALL OF YOUR REPLYS AND WANT TO THANK EVERYONE,AFTER A LOT OF THOUGHT AND QUITE A BIT OF CONCIDERATION I HAVE ALREADY MADE A START AND HOPE TO BE FINISHED IN 2 WEEKS,I HAVE A FREIND WHO WILL STICK IT ON A DYNO FOR ME,I WILL POST THE RESULTS,IM HOPING TOGET OVER 70 HP.WISH ME LUCK FELLAS,I AM VERY EXITED!!

fair play.

look forward to the results