Exhaust valves??
Turbo Mini Forums

People keep saying how bad they are so is there any one on here that still runs the standard metro turbo ex valves???

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

I will be, once my engine's together...

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1967 Cooper 's' Turbo build @ www.drjing.com

me mat, they did not put these into production for nothing

its the high spring pressures created by the modern lift cams which have given these valves a bad name

whats needed is the spring pockets to be machined to take into account the extra lift! from standard

the killer for these valves are ...... especiall the phase 2 cam! with its massive lift on the exaust side!

this contributes to duffing up the followers! also

if the machining has not been taken into account on the spring pockets.

this is the problem IMHO.

you have set a good debate here mat.

having said that, the phase 2 is a excellent cam, once i timed it in right.....lol

BEN:

Edited by BENROSS on 5th Oct, 2005.

I run them and so far I've had no problems.

I would never run them because they are shite in the flow department! 8mm exhaust valves?
I'd rather fit some 6mm from MED or similar if funds allowed.

I used to run 6mm zorst valves, the valve's themselves were 31mm SRE Stainless race valves - worked a treat!

Hannibal: There are two ways we can do this: the easy way and the hard way. In a few minutes my friends and I are going to come down on you like your worst nightmare. You're gonna wish the Earth had opened up and swallowed you whole.
bad guy: What's the easy way?
Hannibal: That WAS the easy way.

Running standard at the mo woth no problems, but as ive got a set of 29.3mm rimflo's im going to try them next year.

-MINI CLUBMAN 1380 TURBO-

On 06/10/2005 06:47:06 Choppo said:

I used to run 6mm zorst valves, the valve's themselves were 31mm SRE Stainless race valves - worked a treat!

AlexF

The argument about the sodium filled valves is they are made of two pieces of metal.The stem and the valve part.

On this site there has been evidence of the two parts eventually breaking apart causing lots of damage, usually the head,piston and often the block are left as scrap after this happens.

The sodium filled valve is a great item but you can't get them new so how old are the ones you are going to use?.. upto 22 or 23 years possibly.

I personally would not run them now,although i have with no problems in the past. A £10 stainless valve is more then adecquate and will give more flow.

JF.

you have a point john with the flow rating and the age of them

Cheers people and good point there Ben.


well I to am running them and I to think there ok, I can't see the flow side of things being a big issue, but yes I was worried about the 2 piece issue.

people fit other valves with the thought of getting away from the 2 piece valve, but rimflows I believe are 2 piece and the guy at mini spares said to me once that they have had heads come off them before, could be down to like Ben says though.

one good thing said about this is the price of NON turbo valves, as Turbo ex valves are i think around £27 each!!! added to that you don't need to get the guides machined out either!

speaking of that point do you that run a more normal valve, do you make the ex guides have a bigger running clearence like you should on the turbo ex valves???

Matt

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

I'm making a new head for my turbo now, and I'll be using bronze exhaust guides, but iron inlets. The bronze ones require more clearance as than iron, but they should really have an even bigger clearance as being turbo.

The flow issue for me is a VERY big part of the equation. Instead of heating up the valve even more, you get the gases OUT! Where they belong

I've got some Rimflos, and they are defo one-piece.

Most valves are two piece... thats not a problem... they are two piece on a BMW M3 for example.

THe point is exactly the one Jon has hit... AGE! Or to be more precise number of cycles till failure.

Alex

AlexF

I use stainless valves, but my thoughts are:

why even risk sodium vavles, when stainless do the job just fine, and are a lot cheaper.

Team Racing

yes Jim has any one had then burn out??

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

cant see to much of a problem with either rimflows or race stainless valves.

the valves wont get as hot for say a test turbo layland lump as they used to have to run them flat out for thousands of miles before they were suitable for road use and we dont do that.

i would use bronze guides all round and have always found they leaked less oil down the stems as iron ones.

once fitted ream with a 9/32 reamer and away you go . actually they need less of a running clearance than iron as bronze are self lubricating so needs less servicing than iron.

my old iron guides were fucked after 1000 miles with a 276 with 1.5's when i fitted bronze they lasted 4 years.

always looking for them bigger bunches of bannanas

good point hoggy!, thanks.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

but then again the std engine is 94bhp....

Alex

AlexF

yes another good point, hell i'm running out of good points here

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

good point alex but under the tests the exh gas temp would be fing hot for a very very long time unlike thr cars we drive as at most the cars are driven hard for only short bursts in comparison

always looking for them bigger bunches of bannanas

My experience is that bronze alloy guides wear far worse than iron ones.
Hog: You didn't alter anything else, JUST the valves?

Bloody hell I remember this thread, how'd you stumble on this. Lol

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1/4mile in 13.2sec @ 111 terminal on 15psi

I thought i was funny, i couldn't remember posting theis, i then saw the date!

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

Standard valves for me....

I only ever had problems when larger, offset valves were fitted into another head I had used...


Why doesnt someone get some Inconel valves made up for the exhaust ??

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will