roller rockers

[olidaviesuk]

Has anyone ever developed, used or knows where to get roller tipped rockers for the 5?

They're used quite a lot in A' series tuning circles as the rocker ratio on the mini is only 1.25:1 at best, and increasing the ratio is a easy way of getting the valves open and closed quicker, hence, maximising the amount of time the valves are open..... (I know its a bit more complicated the that and involves a lot to do with cam profiles etc)

I think the 5 is nearer 1.5:1 but haven't got figures to hand, hence, wouldn't see an immediate gain like you would on the mini, but, if you used rockers like the titan motorsport ones would really help toughen up the valve train for high rpm use...

[Lewis]

Renault did on the Maxi, but that had a crossflow head and I cant see the maxi rockers being able to be used on the C1J.

I have the standard 5 ratio wrote down somewhere if you want it.

[Andrew Cooke]

Renault did on the Maxi

are you sure on that?

[Lewis]

If your suggesting otherwise that gives me a very good reason to doubt myself.

I'd have to dig the maxi parts manual out and see if that shows them in more detail.

If they weren't roller rockers than I'm sure there was something that was different about them, perhaps a higher rocker ratio?

[Andrew Cooke]

it's the first I've heard of it if they are roller, the engine could certainly use some high ratio rockers.

[olidaviesuk]

hmm, so not looking like there are any about for the C1J, might see how much a set can be knocked up for next year, the fact that it'd be a one off will probably mean mega $$$$

[TNT!hammond]

I had some bushed rockers for my mini , they cost very little in comparison to the high lift roller type. still gave me the 1.5 ratio though well sorry actually 1.4 but was enough. Could you do the same on the cij? From memory the hole where the shaft runs through gets drilled out and then a shim is pressed in which is offset to the original shaft. A little like camber corection bolts, my rockers only cost 50quid to have done by a mini engineer. Just a though

[olidaviesuk]

Now thats very interesting to hear... Still not 100% on what the C1J rocker ratio is, should really get round to looking it up... :crap:

Thinking more roller rockers to get more strength in the valve train, as everything else is available off the shelf, or not that extortionate to get made up, kent cams can do titanium valve caps and collets if you ask them nicely, you can also get uprated pushrods done for realistic ££, the buckets are not much of an issue - all equals 7,200rpm regularly without having to *h*t yourself everytime the shift light comes on.....


I had some bushed rockers for my mini , they cost very little in comparison to the high lift roller type. still gave me the 1.5 ratio though well sorry actually 1.4 but was enough. Could you do the same on the cij? From memory the hole where the shaft runs through gets drilled out and then a shim is pressed in which is offset to the original shaft. A little like camber corection bolts, my rockers only cost 50quid to have done by a mini engineer. Just a though

[TNT!hammond]

not being funny ollie but mine seems fine up at those revs , just the stem seals that dont like staying on lol.

[Lewis]

Right checked the maxi parts catalogue, if the pictures are to be believed then the maxi didnt use roller rockers.

Got some other manuals on a hard drive for the 5gtt and 5turbo somewhere so will have a nosy at the rocker ratios quoted.

1.5:1 looks to be the correct figure for the 5gtt though.

1.6:1 rings a bell but there are some many fiures in my head that may be for the gordini or the 21 turbo!

[olidaviesuk]

Hmm, might be just being paranoid then, have a habit of trying to over engineer everything, would rather do that than miss a race due to mechanical failure :(

hah, my stem seals went in the bin ages ago :cool:

surprised the maxi never was developed that much, especially since was the final evolution of the grp b car....


not being funny ollie but mine seems fine up at those revs , just the stem seals that dont like staying on lol.

[Os8472]

not being funny ollie but mine seems fine up at those revs , just the stem seals that dont like staying on lol.

Valve stem seals are for whimps :D

[Andrew Cooke]

Hmm, might be just being paranoid then, have a habit of trying to over engineer everything, would rather do that than miss a race due to mechanical failure :(

hah, my stem seals went in the bin ages ago :cool:

surprised the maxi never was developed that much, especially since was the final evolution of the grp b car....

how many cars had roller rockers in 1984?