Broken valve spring replacement

**Bear family** · 08-08-2019, 17:55

Hi. I have piper double valve springs on my 1700 xflow. Have just noticed one is broken during a rebuild. Is it okay to change just one spring and of a different brand or have I got to splash out on another set?
cheers

**Graham** · 08-08-2019, 18:24

technically theres no real reason why you cant, but as one has broken i would want to test all the springs to see if any of then have gone weak

**Bear family** · 08-08-2019, 18:43

I think I may just bite the bullet and get a new set. As you say, If one has gone then others might follow.
Next question then, does anyone know a supplier for xflow double valve springs in the midlands? Was hoping to get engine done this weekend but this has set me back.

**wozzah1975** · 08-08-2019, 23:39

Do you know what spring rates you need? There are multiples available

**katana** · 09-08-2019, 08:00

I'd be asking why the spring broke in the first place ?

**Bear family** · 09-08-2019, 09:30

Have no idea on spring rate required. The cam is a Kent 244 with 111mm length valves. 41.35mm exhaust and 34.9mm inlet
These springs are off an engine purchased from eBay that valves were connecting with pistons and blew up! Checked the 2 valves and they are straight but the one spring was damaged. Katana you have commented on my engine build thread to build a complete new bottom end. I am re using the head off the blown engine to put on that.

**Bear family** · 09-08-2019, 16:59

All sorted. I have been down to see john Wilcox. He has sorted me some sr7 springs and new spring caps.
A smashing bloke and some serious engines been built! A man with many years of knowledge!

**wildo105e** · 09-08-2019, 17:30

His reputation precedes him. If you have big bucks you can buy a nice BDA.

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**Bear family** · 09-08-2019, 20:18

bout 35k

I've been looking at the head and noticed some play in the valve/guide that the spring was broken on. I'm going to speak to the machine shop about getting the valve guide replaced.
I see a lot about bronze valve guides. While I'm replacing pretty much everything, is it worth asking for a cost on getting all changed.
I don't have a endless pot of money like the bda boys. Hope less than £150

**Forest_rallying** · 10-08-2019, 07:26

Originally Posted by wildo105e

His reputation precedes him. If you have big bucks you can buy a nice BDA.

Sent from my iPhone using Tapatalk

John Wilcox is one of the most genuine people in the buisness and calls a spade a spade, he'll also share information about engines with you that others won't. It might be worth getting a price off him to fit bronze guides and cut the valve seats on your head, I doubt you'll get it done for £150 though.

Why not try Dave Rushton in Stoke, he should be able to K line your worn valve guides. I'd be very wary of using second hand valves that have been touching pistons.