First run with QED 420 Cams

[mark030358]

First run this evening with the 420 QED cams and head porting...

All I can say is WoW.... just stunning, backs of pull at all road speeds in all gears... well pleased.

Down side... an oil leak from the front drivers side.... a large one... perhaps the gauge fitting I think, too much for a gasket (I HOPE)... o well job for tomorrow.

And I can recommend the Brise starters... excellent

cheers

Marl

[S2Jay]

Thanks much for the report, Mark.

I am considering a similar setup for the rebuild that I have started, and it sounds as if you have the sort of performance that I am trying to get.
One question or concern that has occurred to me was if the larger ports & cams caused any loss of bottom end power for clutch take up when just driving about town.
If you would like to share any further info on your engine setup, I am very interested in what valve sizes you used, and what compression ratio.
Also, are you running Webers, or what carbs, and did you also modify them for the cams?

Congrats on a good job and putting another strong Elan on the road!
Best of Luck with the Oil leak.


Jay
26/5009

[Foxie]

One question or concern that has occurred to me was if the larger ports & cams caused any loss of bottom end power for clutch take up when just driving about town.

I fitted a QED 420 spec head and cams quite a few years ago, and was very pleased, not only with the extra power, but also at the extreme flexibility compared to the original spec. I would have no concerns at all

[mark030358]

Oil leak traced to the oil pressure gauge adapter, now dry as a bone.

I also fitted a Burtons water pump unit at the same time and strangley the the car appears to be running cooler... just over 70'ish... maybe its me.

But well pleased.

cheers

Mark

[Uboat]

Hi Mark,
I am thinking of using these cams also. What modifications did you need to fit them? Valve springs?, higher compression? pistons? Did you also fit a big bore manifold exhaust?

/Ulf

[mark030358]

Have pm'd interested parties...

thanks

[Foxie]

I am thinking of using these cams also. What modifications did you need to fit them? Valve springs?, higher compression? pistons? Did you also fit a big bore manifold exhaust?
/Ulf

The valve spring pockets need machining to take the high lift of the cam, and consequently different springs will be required, also the spring rate will depend on your rev limit. QED used to do all this, but I think don't do it any more, but I think one of their machine shop men may be doing it now. Pistons and compression are not dependent, I am running with 10.6 no problems with regular fuel. Big bore exhaust would be a plus.

[miked]

I believe it is Paul Exon who used to be part of QED. Now Exon

http://raceengine.co.uk/

I have not been there but believe he was one of the main QED men.

Mike

[gordont]

Have pm'd interested parties...

thanks

can you copy me on the mods you did please? I am looking at going down the QED420 route too...

[john.p.clegg]

Don't you also need the pistons with the larger/deeper pockets?

John

[rgh0]

Whether you need new pistons depends on the cutouts you already have in terms of depth and diameter and the valves you put in. You may be lucky and be able to use your existing pistons depending on the clearances you have

You do not need to deepen the valve spring pockets. You need to replace the whole valve gear to accomodate the higher lift and there are spring sets available now that give the lift required without doing this pocket deepening which was the approach 30 years ago but is no longer required with the better spring and retainer designs available now. It is also not desirable to do this deepening as the gap between the base of the pocket and the inlet port is small and you risk breaking through. ( been there, done that, welded it up!). If you have a look at a Hart head you will see they routinely broke through in this area from the spring poket to the inlet port becasue of this deepening and they sealed it with epoxy - but then those engines were rebuilt after every race and thrown away at the end of a season !

cheers
Rohan

[Per222]

Hi Mark,
Can you please also copy me on the modifications you did? I am specially interested in carb settings in a high performance engine.
Thank you
Per