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Re: Advice on skimming head please!
Posted: Mon Feb 01, 2010 8:28 am
by blueflag
If I go the route of making new cam gears, and make them adjustable, is it just a matter of making a backing plate with tapped holes and tightening it up when in position? (maybe dowelling too?) Also is there anywhere I can find out the procedure for timing the cams on the NC23, I realise I'll need to make up some brackets to hold DTI's for TDC etc. get a timing disc and so on.
I've never done cam timing before, so be patient with me!
Cheers
Mike
Re: Advice on skimming head please!
Posted: Mon Feb 01, 2010 10:29 am
by racesupplies
I dont know what your timimng figures are,best ask Graeme or someone.I could give you some for Kent Cams,dont know if they are the same figures as stock,they are only base circle regrinds so I think they should be the same.Not sure though,all the stuff I have done before have been built up or completley new cams made from blanks.If you want to know how to make the hubs and gears yourself I would rather PM you as it will go on for ages.
If you are a toolmaker,have a dividing head and know your steels it a nice little project.
The only bit I cant do is the hardening. Cheers Carl.
Re: Advice on skimming head please!
Posted: Mon Feb 01, 2010 12:27 pm
by blueflag
Carl,
You may well be my saviour! Could you PM me the details when you get the time?
Cheers
Mike
Re: Advice on skimming head please!
Posted: Mon Feb 01, 2010 1:01 pm
by racesupplies
Hello mate,I am working at the moment,if you are online tonight I will run through it.Its not that bad,I have two working OK.Straightforward turning work,you will need to know your steels.Mc Creadys have an advisor that will sort it,or I can ask my gear man.Probably use his heat treaters as well.
Re: Advice on skimming head please!
Posted: Mon Feb 01, 2010 8:23 pm
by racesupplies
PM sent.
Re: Advice on skimming head please!
Posted: Mon Feb 01, 2010 9:21 pm
by racesupplies
Did that do it?
Re: Advice on skimming head please!
Posted: Tue Feb 02, 2010 6:04 am
by blueflag
Carl, you're a star!
Thanks mate.
Re: Advice on skimming head please!
Posted: Sat Feb 06, 2010 2:21 pm
by blueflag
Well, after much thought and weighing up the pros and cons, I took the lazy (yeah, right!) way out and offset the gear in the camshaft drive train to allow me to raise the compression.
It only took me 3 goes.... First time, I offset it by 10mm, wouldn't even fit in the barrells!
Second go, I went for 7mm offset, yep, you guessed it, still had interference. I considered putting a little clearance into the top section of the crankcase to get it in but I didn't want to risk ruining the cases.
I settled on 5mm offset, it just fits in and has given me only .25mm height drop, not the .5mm I wanted but better than nowt.
It's occurred to me that rather than machining the barrells by .25 to lower the head I could just leave out the base gasket which by coincidence measures .25 also. I thought that a nice clean face and a smear of Hylomar would be ok. Thoughts please?

Re: Advice on skimming head please!
Posted: Sun Feb 07, 2010 12:11 pm
by greggo
Can you post a picture of the offset cam drive?
Had a quick look at the hylomar website and I think as long as you use something like this on the BASE you will be fine. I didn't see anything on the site that will cope with high compression loads, and you will probably need to glass the cylinder block to make sure you get a good clean seal. As the crank case doesn't deal with high pressure loads that only leaves high temp and automotive fluid to deal with.
Hylomar AF (Advanced Formulation)
Hylomar Advanced Formulation is a solvent free non-setting gasket and jointing compound based on the non-setting Hylomar Universal Blue polymer system.
Hylomar Advanced Formulation has an unlimited assembly time making it ideal for use on components that take a long time to assemble. The product does have some differences to Universal Blue in that the gap filling capability is slightly reduced but it can be applied via robotic application.
Hylomar Advanced Formulation is widely used in the automotive industry, particularly on gear box and transmission housings and flanges, where it is resistant to gear oils that attack silicones. AF is known to apply smoothly and easily without the maintenance issues and curing problems associated with silicones and anaerobics.
Hylomar Advanced Formulation is particularly suitable for use as a solvent free gasket dressing to aid positioning of gaskets prior to assembly.
The product is available in standard and high viscosity grades.