Valve Springs/spring Ratio Mi16

[mmt 15]

Hi,

 

I suspect that the valve springs in my mi16 engine are pretty worn.

 

I feels like the valves floats even as low as at 6500 rpm. Don´t know how old og how many miles the springs has done...I suspect that they are the originals it was born with.

 

Is there any valve springs from any of the new engines that will fit straight in.

 

AND

 

Do anyone know the spring ratio of the mi16 valve springs as I prefer new ones to have a higher ratio.

 

OR,

 

Do I need aftermarked doubble springs? I don´t want to rew the engine above 7000-7500 rpm.

 

 

Thanks

[Sandy 191]

The most reliable off the shelf springs, in my experience, are Piper. Not too badly priced either.

[petert 588]

I buy Catcam replacement single springs from QEP. Can't recall the part number but Matt will know.

 

A good standard spring looks like this:

70lbs @ 1.565"

180lbs @ 1.215"

 

If you get less than that throw them in the bin. Your springs may be stuffed, or must likely, incorrectly shimmed after getting valve seats cut. Installed correctly, a good Mi16 spring is a work of art.

 

Installing double springs in an Mi16 is expensive as you need to machine the head for new spring bases and fit new retainers. Only worth the effort if fitting solid lifters and revving past 7500.

Edited October 16, 2009 by petert

[mmt 15]

Peter, Are those QEP replacement springs the same as standard Peugeot ones? Or are they better than the original Peugeot ones?

Do you remember what QEP charge for a set of replacement springs. Depending on price I might be better off buying springs from my local Peugeot dealer!?

 

Don´t think that there have been done any shimming other than the shimming it was born with.

 

Could it be the cams that are worn? They seem ok and don´t appear worn though.

 

Thanks

[petert 588]

The Catcam springs have a half less turn than the Pug spring, so ultimately wouldn't last as long. I doubt you're looking for 300000+Km though?. This also allows the spring to accommodate more lift. The max. lift with a standard spring is approx. 0.430". I've run them to 7500 on my race engine. Matt says his run them to 8000+. The Mi16 springs are more than twice the cost.

[B1ack_Mi16 67]

I'm also using the single catcam ones. Have had them upto 8000rpm.

 

They are said to handle 8500rpm.

[Sandy 191]

The only XU valve spring breakage I've had, was with the Catcam singles. Correctly installed, Catcam hydraulic profiles, 7500rpm limit, 2000 miles.

[mmt 15]

Piper one vote

 

Catcams 2 votes

 

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