10 replies to this topic

[M111OWW]

Just wondering what people's opinions are on using 1.5 roller tips with sw5 cam on a John cooper conversion Spi cooper..

For mot time would the standard 1.3 rockers be a better option?

Just thinking in terms of emissions

[brivinci]

I have heard that running 1.5 rockers with a cam on an SPI is not recommended. JCG put 1.5s on the cars because they weren't going to install cams (pull the motor). A better option would be a set of proper 1.3. Although stock are said to be 1.3, in actuality they are more like 1.2.

That said, I believe Swiftune says the 1.5s work well with their cam so I'm not sure.

[Gr4h4m]

Best to ask the cam grinder

[brivinci]

Not for nothing but Swiftune only sells 1.5s so my guess would be that they will say go with them. Contact Keith Calver if you are interested in an independent view on it.

[CarsOrBikes]

1.5's will work with the cam, but the emissions 'might' be an issue putting it just outside the tolerance. Running wise, it'll be nice, bit lumpy, but set the fuelling to match.

[spiguy]

Calver is now doing his own 1.4's. Maybe that would be a better option - certainly less stressful for the cam. Maybe worth giving him a shout, he is very quick to reply and extremely helpful.

[brivinci]

I just saw that he has the 1.4s. I recently had him do my head and bought pistons, cam, and others for rebuild from him. He said to just stick with stock or find a good set of 1.3s. I wonder if he would still say that with the 1.4s he has now? Not meaning that he would ever try and up sell anything...NO WAY. Calver is a great guy and actually talked me out of buying a bunch of much more expensive items from him. He said the 1.5's were not ideal though but 1.4s might be just the ticket

[spiguy]

I just saw that he has the 1.4s. I recently had him do my head and bought pistons, cam, and others for rebuild from him. He said to just stick with stock or find a good set of 1.3s. I wonder if he would still say that with the 1.4s he has now? Not meaning that he would ever try and up sell anything...NO WAY. Calver is a great guy and actually talked me out of buying a bunch of much more expensive items from him. He said the 1.5's were not ideal though but 1.4s might be just the ticket

 

I think it depends on the cam you went for. He has recommended I go for the GT spec head and a piper 255 cam. He said that the 255 is intended for use with the standard rocker, so no point in going for the 1.4's - I asked him specifically about that as I figured that it would be worth the extra (they aren't that expensive anyway) if it would give a little extra.

Edited by spiguy, 02 November 2015 - 10:47 PM.

[brivinci]

That is the cam I have currently. Had a SW5-07 before that. This one acts a little different. I'd say that its the same as the SW5 but it has a stronger "feeling" powerband from 4k on. You really feel it when you get to 4 and beyond.

[spiguy]

What head did you go for brivinci? and did you go for the cheaper or more expensive followers? (they both have been ground to the correct profile, but the dearer one is taller or something?). Keith reckoned that the GT spec head would be all that I would need for my 92 SPi.

[brivinci]

Keith did a a custom head for me. I think mainly because he didnt have anything "on the shelf" to me. 35.7mm intake and 29.5mm exhaust valves. Might be exactly like what he typically sells for injection cars but we talked a lot about what to do with it. I wanted RimFlo valves and bronze guides and all that and he said that would be vast waste of money. He also said to go with the standard followers he sells. Race versions were not needed for my build. Thats what I love about Calver, hes in it for the motors, not the money.

 

I will say that I will ONLY ever buy followers and timing chain from him. I have had terrible luck with both from all others. Its amazing when you get his followers and see the difference. Mine were totally flat and with his installed, I can watch my pushers spin while I turn the motor over by hand. Dont get me started on the quality of chains either. Keiths are a must!

 

Off topic but I also went for his special pistons. They looked to be much nicer then the previous ones installed and even my machinist said the same.