Like this:
| Fitting a 4:1 Exhaust Manifold to a Vauxhall Astra GTE 8v |
| Apparently the standard cast 4:2 manifold and a decent 2:1 downpipe are quite good on a 2.0 8v engine. However, there comes a time when quite good can be improved. With the twin 40 Dellortos in place and some more cam, I was hoping to improve high rpm results by fitting a 4:1 tubular manifold. This was supplied from Opel fan Mattheus in Brazil in exchange for some 2.0 16v parts. Postage was expensive though. Anyway, big thanks to Matheus. |
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The standard manifold was removed. Note the 1.8 distributer with oil catch
tank nicely oiled up behind. |
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The new manifold ended where the 4 pipes joined in the collector. The down
pipe on the car was a Jetex
one with different fitment from the standard 8v system. The sprung loaded
joint had been fitted by Powerflow
exhausts when the original one rusted years ago. The rest of the system
was by Longlife
exhausts. So a right mix of parts. Anyway, the plan was to cut the end of
the existing down pipe and then match that up with the end of the new
manifold. There was quite a big gap to make up - about 4". In order
to get the parts in the right position then we welded two small strips on
first, then lined everything up, then tacked the strips in the right
position.
Like this:
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The tube was made by cutting two plates from sheet and then bending these
into the approximate shape.
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The edges were trimmed until they made a reasonable fit. They were then
welded on and hammered into shape as the welding progressed.
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It was then all fitted into the car. Looks loads better than the original
manifold.
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Good oil-water mix under the car.
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