Hi. Anyone have any experience with these Hi lift rockers? Do they make a difference? Did read Hi lift rockers can increase top end but lower low end performance. Don't want to replace the cam.
Would it depend on engine Hi lift rockers fitted to?
At present engine has the original pressed steel types on a polished and ported 10 stud 1 bolt 12g940 head. Engine from a AD016 1300GT. Would mini spare 1.5 rockers be worth change?
Thanks
Mini spares Hi lift 1.5 forged rockers
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Re: Mini spares Hi lift 1.5 forged rockers
Hi Robbie,
Your info gleaned so far is pretty much bob on, 1.5's will do exactly what you say, slightly increase top end, but at the cost of a bit at the bottom. I have run them on my 850 (amongst others) for years & they certainly offer an improvement over the std pressed ones. However, if you are using them on a standard engine, a better head would give a better improvement, but at a higher cost of course.
Your info gleaned so far is pretty much bob on, 1.5's will do exactly what you say, slightly increase top end, but at the cost of a bit at the bottom. I have run them on my 850 (amongst others) for years & they certainly offer an improvement over the std pressed ones. However, if you are using them on a standard engine, a better head would give a better improvement, but at a higher cost of course.
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Robbie224
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Re: Mini spares Hi lift 1.5 forged rockers
Thank you. Glad I asked despite reading the pros and cons. Probably leave it as it is.
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DougR
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Re: Mini spares Hi lift 1.5 forged rockers
Hi robbie224, I understand that you want to avoid taking out the engine and what you have in mind is fine. I assume you will buy the complete assembly
because the posts are different. If, on the other hand you were thinking of taking the engine out in the future, it might be worth considering changing the cam. Keith Calver does a modded version of the Piper 255. He has added extra lift so 1.5 rockers are not necessary and also the cam is cross drilled for lobe lubrication. In this case you can use your original rocker setup or you can buy 8 of 12g1221 cooperS rockers which will work with your original posts and will be a lot cheaper. If doing so I'd replace the shaft as well as it's not expensive. Hope this helps. Doug.
because the posts are different. If, on the other hand you were thinking of taking the engine out in the future, it might be worth considering changing the cam. Keith Calver does a modded version of the Piper 255. He has added extra lift so 1.5 rockers are not necessary and also the cam is cross drilled for lobe lubrication. In this case you can use your original rocker setup or you can buy 8 of 12g1221 cooperS rockers which will work with your original posts and will be a lot cheaper. If doing so I'd replace the shaft as well as it's not expensive. Hope this helps. Doug.
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Robbie224
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Re: Mini spares Hi lift 1.5 forged rockers
Hello Doug. Your post does help and that might be something to think of doing in the future. That calver cam sounds good . Engine has only been rebuilt 2 years ago with proberly less that 2k miles. Manly was just looking for simple way to increase performance..
Rob
Rob
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Robbie224
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Re: Mini spares Hi lift 1.5 forged rockers
Hello Doug. Your post does help and that might be something to think of doing in the future. That calver cam sounds good . Engine has only been rebuilt 2 years ago with proberly less that 2k miles. Manly was just looking for simple way to increase performance..
Rob
Rob