18 replies to this topic

[Sir Yun]

Duration has an effect on the pumping losses. It is the lift and profile you should match to suit the peak torque area requirement for your spec

What is the effect of cam duration on pumping losses ?

So you suggest an even shorter cam with less timing (230) and a smaller lift integral would will be better for a long stroke engine with inherently asthmatic breathing.

Why ?

[Innodetomaso]

Very interesting topic, as I have started a very simular engine build !
My goal is to create a smooth running modded 1100 for my Mini estate project,
so no streetscreamer spec's but all the mods and nice goodies are focussed to get more torque, and drivability.
Although...once started, I could not resist the temptation, and had my crank wedged and balanced
At this moment I have all the parts in house and I am planning to build the engine during the dark December period.
My spec's:

pre A+ 1098cc +.060"" (1150cc)

Calver ST small bore stage 3 cylinder head, 30.94 inlet / 26.42 exhaust valves
Swifttune SW5-07 cam
MED big shaft 1.3 roller tip rockers
Duplex vernier cam gear / chain
Calver ST 1098 piston set +0.060", CR 9,5
Lightened & balanced std. conrods / wedged & balanced crank / (little bit) lightened & balanced flywheel
H&H 65DM4 full electronic distributor and coil kit, modified advance curve
inlet manifold Howley 1"3/4, HS4 carb
Small bore LCB exhaust + RC40
3.1 Final drive ratio

I will be following this thread

Edited by Innodetomaso, 03 December 2012 - 05:59 PM.

[Skinartnz]

Ok have crank!!!!!!!!!!

Here are some pics of my bits to date..

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[Skinartnz]

Pistons fitted and block painted

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