Arden Combustion Chamber modification

[Fanfaniracing]

Hello Guys!

I have the Problem that my new Arden Head has only 21cc of Volume insted of 25cc like the old one i had. So my Question is where in the Chamber can i take Material away without make bad influence in Flow Caracteristics? Any Ideas, Sugestions?

Thanks for your inputs...

Fabian

[Dr S]

Dished Pistons?

[Richspec]

we were always of the opinion that there wasnt much scope to increase the chamber size, I think i may have read that somewhere on here perhaps? Both our Minispares ardens are the older smaller chamber type although I think the ex Harris hillclimb one in my brothers car has had some work, I'll see if i can find the details.
The original Arden we have has massive valves and the tiniest chamber ever, something like 16cc springs to mind.

edited to add we never calculated the CR when we built either 8 port, it was a case of thats the engine we have thats the head, bang em together, job done.
I do remember that back in the day the original arden + swiftune 1380 short motor went so quick it was unbelievable, and that it was impossible to physically push the car past compression.

[mk1]

Yup, Could do with a bit more info. What version of "ARDEN" head is it, original, BMC, Minispares, Minispares new version? All are a bit different.

If you can do it with dished pistons or even decking the pistons it would be better than modifiying the chambers on your head.

M

[rich@minispares.com]

the new minispares heads have 21cc and work fine on 1460's

dont forget that an arden likes a big cr,

[Fanfaniracing]

My Head is the Minispares latest Evolution Head. Like Rich says, it has a Chamber Volume of 21cc.

The Pistons have a dish of 8cc.

How much will the Cometic Gasket give? I calculated with 1cc...

Thanks for all your efforts!!!

[Vegard]

21 and 8 will NOT make high CR on a 1275. What was your old engine, 6:1??

[Fanfaniracing]

+ 60 will give 1330 oder?

[smithyrc30]

If the motor is 1330 and the figures for the gasket, piston and head are correct (total 30cc) then the Cr is 12.08:1

[Fanfaniracing]

Sorry, the Dish in the Piston is 7cc.

But i don't know how much cc the Gasket will give. It's a 3 Layer Cometic. Someone has Infos
about this Gasket?

Is 12.4:1 not a little bit high Compression?

[rich@minispares.com]

Is 12.4:1 not a little bit high Compression?

not on an arden

they like it to be high - up to 14:1

[Fanfaniracing]

Rich, 14:1 is almost a Disel Engine?

Do you know how much cc the Cometic Gasket from Minispares
will give?

[Oldskoolbaby]

Yup, Could do with a bit more info. What version of "ARDEN" head is it, original, BMC, Minispares, Minispares new version? All are a bit different.



M

Sorry to hijack this a little but how would one tell whats what? Are there different identity marks on them or different casting shapes? I got my hands on a lovely head for my 970 build but I'm unsure of it origins too.

[Astro]

yes, I would learn this too. But please annother hijack. Whern trying different rockers with my Arden, I learned that there was a big difference between 1.5 and standart rockers, bigger than with a five port. Just by accident?

[Fanfaniracing]

As i know, there was the heads stamped Arden, Mowog Heads, Arden Heads from Minispares and the last Arden Heads from Minispares with the CNC machined Chambers/Ports. Please correct me if i am not rigth.

Concerning the Rockers, i have the ones from MED. They say that they were specialy made for the Arden.

[Richspec]

Yup, Could do with a bit more info. What version of "ARDEN" head is it, original, BMC, Minispares, Minispares new version? All are a bit different.



M

Sorry to hijack this a little but how would one tell whats what? Are there different identity marks on them or different casting shapes? I got my hands on a lovely head for my 970 build but I'm unsure of it origins too.

the castings do look different.

[Oldskoolbaby]

I take it the one with the flat surface around the rocker posts is the MiniSpares Arden? Is there any advantages over older heads or is it the other way around. I'm aware that the older heads can become porous over time.

[Richspec]

yep the newer one has the flat surface, but even that's an older minispares casting from the 90's. the newer ones are supposedly better again but Rich will have all the info on that.
When we got the original one yrs ago it needed some repairs and rob walker did all that and had it pressure tested.

[App K]

[quote="Richspec"]yep the newer one has the flat surface

Some of the original early "mowog" ones also have a flat surface. They are also numbered in the casting and some show "Mk 2" so I can only believe there was also an earlier head..maybe that just said Arden?

[Richspec]

Rich, 14:1 is almost a Disel Engine?

Do you know how much cc the Cometic Gasket from Minispares
will give?

i could do with the answer to this as well to calculate cr

i'm measuring the chamber cc at 15cc?

on the cometic do you cut off the rivets as they dont clear the head?