Nuvite II

[mickrick]

horizontal said:

Hi, just seen this thread as not been following Caterhams for quite a while. This was my ‘Silverstone’ from years back, not quite in the same league but I adored it.

Lovely thing!

[Paynewright]

Mickrick - did you get my PM?

[mickrick]

Paynewright said:

Mickrick - did you get my PM?

No Sir I didn't.

[Paynewright]

Sent via the PH email service - did it end up in spam?

Ian

Edited by Paynewright on Thursday 24th February 08:17

[mickrick]

Paynewright said:

Sent via the PH email service - did it end up in spam?

Ian

Edited by Paynewright on Thursday 24th February 08:17

There you were! In spam

Edited by mickrick on Thursday 24th February 16:55

[mickrick]

I finally managed to bead blast the head, a lot of masking and plugging... I think the car it came from must have rolled into a field. It was quite mucky!
I then drilled out the two Advel rivets, and tapped the holes for ORS plugs, and gave it to my local to work machine shop for an ultrasonic bath.
It came out quite nice, like the block, all the nasty oil staining, which my parts washer wouldn't shift, gone.

[Farlig]

Lookin' good Mick - planning on any porting / tuning?

[mickrick]

Cheers. No porting, these heads breath good enough. I've just tidied them up a bit by cleaning off the casting flash. Can't go mad on tuning, as I have to get it through IVA emissions test. But I may have a bit of a tinker....

[Farlig]

mickrick said:

....But I may have a bit of a tinker....

[mickrick]

A nice little package turned up at work. A bit nicer that the cast ones I took out.
Now I need the rummage in my sock drawer, and down the back of the sofa to find the funds for some rods....

[DCL]

A word of warning - these may not run out of the box. I believe the Cosworth crowns are essentially blanks and may need additional machining to get the required clearances. Or at least they are bespoke to their own CNC heads and cams. I'll look back at my blog and check.

EDIT:

Done that and if these are the 13:1 CR then there's a good chance the intrusion bar is too wide and will get very close to the cylinder head at the sides. If you are using high lift cams then the valve clearance might be tight too. Suggest you do a 'plasticine' check to confirm all is OK.

Edited by DCL on Wednesday 11th May 23:39

[mickrick]

Thanks for the heads up. I bought these through Modatek who support Cosworth historic engines ( apparently the Duratec is coming up to 20 years old, so they're starting to list the parts again) and have had quite a bit of correspondence with the fellow who did a lot of the development work on the Duratec with Cosworth. They are supposed to be a matched set, although I haven't weighed them yet.
He didn't mention anything about machining them. I'll mention it to him next time I write. IIRC these are 12:1.
Of course decking and clearance check is all part of good engine building practice

Correction. The pistons are 12:1.

Edited by mickrick on Wednesday 18th May 11:15

[DCL]

The 11:1 may not be so bad. My photo above shows the comparison with a Supertech piston with the gudgeon pin aligning them. It shows the intrusion bar rebate on the Supertech that gives plenty of clearance to the domed chamber of the standard cylinder head. Cosworth don't do it that way for some reason. A discussion I had with Ultimate many years ago suggested that it allowed the head to be modified without cost to the CR on their own engines. But who knows!

[mickrick]

I was looking at Omega, but their max tolerance was 87.51, which is no good unless you have a brand new block. My cylinders were good, but needed a glaze bust, so they were just over that.
So I went for the Cosworth pistons as their tolerance is 87.50 - 87.53. I was well within that.

[mickrick]

I had a look today. I see no issue with the raised part of the piston.
Obviously I can't measure the deck heights, but by placing the piston on the head with a bit of plasticine, I can see there is no issue whatsoever.
From the correspondence I've been having, if there was, I'm sure it would have been mentioned.

Edited by mickrick on Saturday 14th May 16:24

[mickrick]

Anothe box of Cosworth precious things

[Farlig]

C’mon Mick that’s just a pic of some cardboard boxes… we need to see the engine porn inside!!! ??????

[mickrick]

Farlig said:

C’mon Mick that’s just a pic of some cardboard boxes… we need to see the engine porn inside!!! ??????

[Irrotational]

Wow! I remember reading this thread originally, back in 2010/11, and being very jealous of the shiny polishing that was achieved! 11 years later and I am hoping someone has invented a way to take old curvy, louvered, aluminum and make it shiny with a click of the button!?

I can't believe I didn't post in the thread originally as I spent ages trying to work out ways to polish ali, "the easy way".

Anyway good to see you are working on stuff and hopefully enjoying yourself :-)

[Farlig]

mickrick said: