Is there a noticeable difference with 9.0 :1 compression ?

[Mick Boon]

I took my Lomax for another test drive today it's almost flat out at 72 mph.... Is that about normal ? The engine is very sweet, just slow. Would new 9.0: 1 pistons give it more zip ?

Any good tuning tips would be appreciated.

[Mick Boon]

[kawlomax223]

Sounds about right to me. I'm guessing that 72 mph was on the level? Remember the 2CV would just about do that... on a good day, with a following wind! Although several times I did get my 2CV 'off the clock'! Do you have a rev counter fitted? I'm thinking that at 72mph it'll be about 6500 rpm... just about max. So, just enjoy cruising, it's not just about top speed. IMO!

[Mick Boon]

There was a moderate wind from the side and it was on the flat, and two up. Yes I have a rev counter, and I think it was just under 6500 rpm. All is normal then It's very happy at 60mph

Thanks !

[Ken Hanna]

Peak power of a standard 602 engine is at 5,750rpm, for both 8.5:1 & 9.0:1 compression ratios.
That engine speed corresponds to 72mph if the gearbox has 2CV ratios, 76mph with Dyane/Ami ratios and with tyres having an effective circumference under load of 1.842 metres.
Recommended peak rpm is 6,000 for engine longevity...

[billdavies]

Mike,
Reading this post I see that you have a Lomax so there is a chassis member that you can use to support the Guzzi engine if you go that route.
Part of the reason that you only achieve 70 mph is your pointing the guns forwards, point them over your shoulder and the reaction will increase the terminal velocity...lol
Bill

[Mick Boon]

Mike,
Reading this post I see that you have a Lomax so there is a chassis member that you can use to support the Guzzi engine if you go that route.
Part of the reason that you only achieve 70 mph is your pointing the guns forwards, point them over your shoulder and the reaction will increase the terminal velocity...lol
Bill

Hi Bill, I just replied to your comment on the Pembleton forum, take a look

[Mick Boon]

Peak power of a standard 602 engine is at 5,750rpm, for both 8.5:1 & 9.0:1 compression ratios.
That engine speed corresponds to 72mph if the gearbox has 2CV ratios, 76mph with Dyane/Ami ratios and with tyres having an effective circumference under load of 1.842 metres.
Recommended peak rpm is 6,000 for engine longevity...

I bought it as a 1963 Ami Lomax, but the only things that are from 1963 is the fuse box and the riveted on chassis plate number. Research has confirmed that the engine and gearbox is 2cv, and the chassis is a replacement..... I was only thrashing it so I could see what it could do honest