11 replies to this topic

[paulk 7364]

As above 1.5 ratio what’s best forged or roller
1275 with sw5 cam
Pros and cons please
What make is best to buy
Thanks

[whistler]

Have a read of this from Keith Calver. https://calverst.com...ral-compendium/

[Bobbins]

Have a read of this from Keith Calver. https://calverst.com...ral-compendium/

That's a really interesting read, thanks for posting the link. It's made me think more than ever that for a fast road 1275 the ideal set is probably Swiftunes 1.4 non-roller rocker set, no bearings to give loose tolerances and a sensible balance of torque v power. They're expensive though!

[whistler]

 

Have a read of this from Keith Calver. https://calverst.com...ral-compendium/

That's a really interesting read, thanks for posting the link. It's made me think more than ever that for a fast road 1275 the ideal set is probably Swiftunes 1.4 non-roller rocker set, no bearings to give loose tolerances and a sensible balance of torque v power. They're expensive though!

 

Keith Calver does 1.4 rockers but don't know if he has any stock.

[Shooter63]

I think you will find that Mr Calver supplies Swiftune hence they are both out of stock, Keith did post a few months ago that the foundry he uses wanted to double there price, or offered to get them made in India ( I think) for the same price, i have no idea what the out come was

Shooter

[Spider]

I've tried quite a few that are on the Market and the only ones I found that were any good, in all aspects, are those made by MED.

 

Ideally, you'd probably want to try Rockers in 1.3 and 1.5 Ratios to see what it is that you are seeking. I'd suggest for doing the taste test, finding a used set of 1.5's in either non-roller Tip or Roller Tip, while these won't be the same as a new MED set in how they perform, they'll give you a good idea, just check the actual valve lift when fitting them to see if they are close to the desired ratio.

 

Some also offer 1.7:1 Ratio, which on a N/A Application, I can't see any benefit from.

 

On Stock 1275 Heads, you will notice a difference between the 2 ratios, though to get the most from what the 1.5's can do, the head does need to be worked over.

 

Personally, I prefer 1.3's for street use, but, that's just how I like them to run.

[madaboutcherry]

i have a brand new set of swiftune 1.4 rockers if anybody's interested, never been fitted. i've gone for a supercharger instead.

[Cooperman]

I went from 1.3 to 1.5 roller-tip rockers on my Mk.1 'S'. It has a 286 cam and all the other 'goodies', but changing the rockers only gave an additional 2bhp at over 5600 rpm and I lost some bottom end torque with driveable power coming in some 250 rpm higher at c.3200 rpm.

[alex-95]

I've tried quite a few that are on the Market and the only ones I found that were any good, in all aspects, are those made by MED.

 

Ideally, you'd probably want to try Rockers in 1.3 and 1.5 Ratios to see what it is that you are seeking. I'd suggest for doing the taste test, finding a used set of 1.5's in either non-roller Tip or Roller Tip, while these won't be the same as a new MED set in how they perform, they'll give you a good idea, just check the actual valve lift when fitting them to see if they are close to the desired ratio.

 

Some also offer 1.7:1 Ratio, which on a N/A Application, I can't see any benefit from.

 

On Stock 1275 Heads, you will notice a difference between the 2 ratios, though to get the most from what the 1.5's can do, the head does need to be worked over.

 

Personally, I prefer 1.3's for street use, but, that's just how I like them to run.

I’ve got a set of Med Non-rollers and have found them good, nothing to compare them against in relation to other ratios though, the only problem I had with them was that they were all full of swarf and burrs! 

[Spider]

,,, the only problem I had with them was that they were all full of swarf and burrs! 

 

 

I've always stripped apart any of these sort of bits, cleaned and checked them before fitting, I feel that it's just good practice, even if say they were cleaned, ready to fit at manufacture, what happens in the supply chain after that is a wild card.
 

[madaboutcherry]

i have a brand new set of swiftune 1.4 rockers if anybody's interested, never been fitted. i've gone for a supercharger instead.

the rockers are now sold.

[Alice Dooper]

I’ve a set of 1.5 roller rock RIS on an MPI that came with a works conversion.  Slightly noisy when cold.  The torque curve moved up the Rev range a touch too. They’re working against big double spring and all seems really fine.  Engine breaths really well at 4-5000rpm.

 

if was spacing it outside a complete kit, I’d go for roller 1.4’s though.