I have the answer to point 5 thanks to marcaztls.

5. 160 main jet is needed.

 

:secret:mikuni main too, not keihin etc.:thumbup

 

Hi,

I'm rebuilding my 4XV head quickly and I only have until the 14th, ideally the 8th so there's some time for testing, to get it done.

I've got some questions regarding what I should do while the head is off, I'm hoping someone who's read far more of the 'Headwork winter project' thread can help me.

1. Should I skim the head? If so, by how much? I know measuring your squish is the best way forward but is there a safe amount to take off and use with the standard gasket?

2. Is it OK to split the gasket, measure squish then reuse the gasket for the final build?

3. Porting, am I OK to remove the bottom of the valve guides? Has anyone got a picture of a well ported inlet and exhaust that I should aim to reproduce on my head?

4. Vavles, is it OK to clean these up with some fine grit sandpaper? My inlet ones look pretty black and coked up. (See: http://flickr.com/photos/trottski/3000886204/sizes/o/in/set-72157608625481254/)

5. Splitting the gasket, what size jet do I need for the head and where can I order one?

6. What size and length bolt and tap is needed for blocking the AIS holes in the exhaust ports? Ideally I'd like the bolt to go all the way into the head then file the end to match the port angle.

There's a few pictures of my progress here: http://flickr.com/photos/trottski/sets/72157608625481254/ but nothing that interesting.

1, yes i'd skim the head. (amount depends on other factors that need measuring first).
2,well splitting the gasket isn't ideal, but i guess it's physically possible, as you know. after tension you would need to see if it's still sealable.
3,yes, and here's a pic of mine.
4,i'd use a buff wheel, not sandpaper.
5,order at most bike shops.
6, what ais holes?:dunno:lol
7,you need to speak to a reputable bike building shop
before you decide any mods.:thumbup

 

Thanks Blu.

1. Would you skim the head over splitting the gasket or do both? Is there a safe amount that's worth taking off without measuring?

2. Ta.

3. Thank you - that's very helpful.

4. Will do.

5. Ta. I'm getting one from marcaztls.

6. Do you not have these down-under or do I have the abbreviation wrong?

7. I've been chatting via PM to marcaztls, who has been very helpful. At the moment I don't have time to get anything more complex done apart from a quick DIY polish and some skimming. I've got a Car Club event in 10 days then another track day in 30.

 

:hellobye

1. Yes skimming the head is fine. I'm not going to say a set amount because i treat each motor individually to get the best I can out of it but more than likely someone else can give you a 'safe' number. It does all depend on certain factors which ideally need measuring though so bear that in mind.
2. Yes, splitting or removing the center leaf of a brnad new standard gasket is almost always reliable, no leakage etc. If it's a brand new, dry and clean one and your head and block is clean, dry etc. then it's fine to use that to measure squish, set and re-use. As long as the engine's not run and the black Viton coating is heat-cured then it'll be fine to reuse.
3. I would say yes and I have done that before on R1 and R6 heads, both inlet and exhaust. See pics below for what I do to inlet valve guides to smooth flow once they are port-matched.
4. I take it you mean cleaning the valve faces? Whatever method you decide on for cleaning just remember that the standard valves are coated and once you wear through that coating they're compromised. I use a small brass whell in a Dremel style tool and have had fantastic results. I wouldn't recommend any type of paper.
5. 
6. I've used an M8x40 aluminium bolt (not anodised) and appropriate tap plus copper sealing washer previously. It shapes very well to the port wall. See below.

Inlet valve guide port-matched:

AIS blocking bolt installed:

AIS blocking bolt from inside port:

Remember the M8 bolt will only need tapping on the inner part of the AIS hole (say that out loud...). Hopefully this makes sense:

Oh, and if your motor has the AIS holes than it's actually a 2000-on model, a 5JJ

 

Oh, and if your motor has the AIS holes than it's actually a 2000-on model, a 5JJ

Ah, I didn't know that - thanks.

Thanks for all the answers and advise Mark and Blu. I'll be back at the end of the week with some progress hopefully.

 

lol, mark beat me to it.....mine has no ais.:flex:

 

There's a joke there about it actually having one AIS hole but I'll let BSR make that when he see's this thread... :sing :makeout

 

I wasn't gonna say anything about Blu & his aishole! :lol

I don't know how much I can help after seeing what these guys have already written & showed.

first off, anybody who grinds down the guides is off his rocker!
just kidding.

I respect the opinion of these guys above anyone!

I've heard of guys milling .015" thou without measuring anything & being OK.
don't let this be a substitute for REAL measurements on YOUR actual motor.

I've split gaskets many times with no problems.

for the built up carbon on the back side of the valves, I would put the valve into a drill press & spin it while removing the carbon with a buff wheel for a dremel, that way you can even it all out easier without "burning" through the surface.


I've got a different model (05) so it'll be a little different & I'm almost afraid to post pics after seeing the quality of the others on here. but here ya go!

 

I've got a different model (05) so it'll be a little different & I'm almost afraid to post pics after seeing the quality of the others on here. but here ya go!

:2bitchsla

Good post.

One day I'll find out exactly what equipment top tuners use to get the level of finish and consistency in ports like those that Blu posted and work I've seen by the likes of Tony Scott, Chris Mayhew, Jan Roleouf etc. :fact

 

Did the thread get smaller since it's a weekend project? :dunno

Seriously though trottski, you've got some of the best and brightest giving you advice :fact

 

Did the thread get smaller since it's a weekend project? :dunno

Seriously though trottski, you've got some of the best and brightest giving you advice :fact

Yeah they'll be along in a minute with any luck...

 

I sure hope so! :dundun: