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Re: 138.9 twin cam new build

PostPosted: Sun Mar 10, 2019 1:55 am
by 1owner69Elan
As another data point, from my street engine:

Camshafts: 0.44" lift (both)
Duration: 250 degrees (@.050)
Valve size: 1.625 intake 1.375 exhaust
10.25 compression ratio
Pump gas: 91 octane (R+M/2) equivalent to ~95 RON (Australia and elsewhere)
7000 redline

181 hp @ 6900
143 lb-ft @ 5100 (~flat 4000-7000)


(1.7 liter stroked twincam)

Re: 138.9 twin cam new build

PostPosted: Sun Mar 10, 2019 2:03 am
by Davidb
Thanks to both for that. I am happy to hear from Rohan that he confirms my (el cheapo) plan for more power! I did just this on the last engine I built-not a Lotus Twin Cam-and it seemed to work quite well.

Re: 138.9 twin cam new build

PostPosted: Mon Mar 11, 2019 9:05 am
by 661
Another 'new' twin cam in Sussex

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Re: 138.9 twin cam new build

PostPosted: Tue Mar 12, 2019 11:36 am
by kevin61
Hi Rohan,
Apologies for the slow reply;
Basically the pistons that were fitted are forged High comp pistons that come set to run 12-1 compression but as its a road car we machined the pistons down to run 11.0-1 comp.

k.

Re: 138.9 twin cam new build

PostPosted: Tue Mar 12, 2019 11:38 am
by kevin61
Hi Graeme,
It certainly looks the bis! bet your looking forward to getting on the rolling road!!
K.

Re: 138.9 twin cam new build

PostPosted: Tue Mar 12, 2019 3:34 pm
by 661
kevin61 wrote:Hi Graeme,
It certainly looks the bis! bet your looking forward to getting on the rolling road!!
K.


Not sure it will need much tinkering as the engine builder has run it in on his dyno