Oppdatert:
24.01.09
Besøkende
nr:
315205
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Insight in the Broadspeed replica engine work
I have no exact knowledge
on how the 1977 Broadspeed engine was built. But the Group 2 regulations
that year, homogolation papers together with pictures of the outside of
the engine and the estimated power capability gives me an idea what must
be done. Here I show you some of the work.
| I have started makeing a copy of the unique intakemanifold from aluminium sheet, this will be used as a pattern for casting a new one. |  |
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The pistons are forged lightweight items, weight is 352 grams. The regulations say I can bore the cylinders max 0.6mm and this is done (90.6mm). With the std (70mm) stroke this gives 5400ccm. Pistons has the comustion chamber since the heads is Huron type (flat). I have designed this to give me some squish area and some room around the spark plugs. |
| H-Profile
Forged connectingrod You can see a small cutout at the top of the bigend for oil squirt under piston for cooling Connecting rod is 585 Grams |
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Intake and exhaust port is worked by EBB in Stavanger. The new valveprofiles is matched carefully to porthape and the portsizes is matched to the engines cams and rpm working range. |
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Here you can see the flat style head design of the Huron head. New seats cut out with some moore favourable seat angles. To the Left you see the heads with new aluminium inlet flange and trumpets. |
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Here are the flow figures EBB got out of the heads. Valvesizes is moderate 42mm in and 35mm out to get the desired rpm workingrange.
Moore to come |
