Twin rotor Peripheral port

[stuart wizy]

I think I,ll stick to used parts mate
 gunning for 600 bhp+ out of the fc with the t45 with 8 injectors.
If it pops its cost me a set of 3mm atkins tips :cool
If side housings are clocked flat I cant see the difference from using new to be honest, i know the nitride wont be as thick on a used housing.
If u wanted to check for super toleranced flatness u need to use a surface plate with engineers blue brushed on , then rub it on all side plate surfaces which will show you how flat they are. ie blue spots on side plate is a high spot all silver areas are low spots.
This his how we used to scrape machine beds flat to 5 microns for grinding machines in 20 degc temp controled rooms,
you could then lap the high spots to get plate flatter for better side compression.
grizly if u wanna go real precise I have surface plate and micron clocks bud!
Not blowing my own trumpet but ive built griding workheads with hand scraped phospur bronze bearings, that rotate to 3 microns on runout.
give us a bell if u wanna borrow clocks, verniers or micrometers.

stu
07762331845

[Grizzly]

LOL how do you get a rotor housing flat?  if you take the chrome off won\'t it be goosed? if it has been used won\'t it not be 100% flat?

Yeh you can always go to an Engineering shop and go that way but its hardly DIY??

[stuart wizy]

nothing is ever 100% flat mate

[stuart wizy]

side housings not rotor housings lol

[stuart wizy]

you can lap by hand with a flat block and grinding paste

[Grizzly]

Ok Point made, But how long have you been and engineer??? For a DIY guy in his garage at home would you say its possable to build a 10,000 rpm P/P engine? Of course if you have an engineering shop at your beckon you could proberly make a housing?? but i still say for a PROPER race engine without 20 years of experiance and an engineering shop you have to go new.

[Grizzly]

side housings not rotor housings lol

?? Where do you get most of your Comp from??? Rotor housings??

[stuart wizy]

the side housings are cast iron with nitrided faces that are around .020" thick.
my fc side housings were clocked flat within .003" all over, this is within tolerance but could be better, now they are within .0005" all over.

[stuart wizy]

you get what your given with rotor housings, yep thats were comp comes from, but not 100% of it.

[shaunwil]

Just out of interest what mirons per meter surface finish do you need for this type of work, Too high and it\'ll pass gas through ?? You could get something like this flat by using lapping paste and a proved flat block. They make diamond paste with 1micron partcles in it the fluid. Even if you had a machine shop it isn\'t easy to get something completely flat.

Interesting topic !

Shaun

[Grizzly]

What sort of a diffrence are you expecting?

Experiance engine building is where the Comp comes from. For example side seals, did you know race engines are set up with no gap?

2mm seals will handle 10,000 rpm but 3mm\'s are too heavy and tend to bounce causing chatter.

[stuart wizy]

you dont need a workshop to check flatness,
you need dti with mag base or straight edge and feeler gauges.
new rotor housings are 250 quid each or 100 quid used of tim.
my used housings loooks brand new that i got of tim.

[Grizzly]

LOL so do mine... But i stil bought new ones for my triple. You knever know what the used Housing has been exposed to, Over heated? or it may be cracked? you never know at least with new you know what your getting.

[stuart wizy]

what gap do u mean mate?
rotor housing width minus rotor width.

[Grizzly]

Side seal to corner seal gap

You set them up with the min of gap (just so the corner seal moves freely) the centrafugal force will open the gap enough for expansion, its a old racers trick to get more Compresion.

Theres lots of things like that that racers tend to do to get there compresion as high as possable.