Choosing a new exhaust manifold

Road-race engines and ancillaries - general discussion
Guy Croft
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Re: Choosing a new exhaust manifold

Post by Guy Croft »

no worries, just get it right, OK?

G
Brit01
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Joined: June 28th, 2011, 4:54 pm
Location: Uruguay

Re: Choosing a new exhaust manifold

Post by Brit01 »

I had a long discussion with a local mechanic in the rented parking slot I use about the firing sequence as he was watching me install the HT cables and commented that I had them on the wrong way.
He just couldn't believe the sequence of the Alfa boxer. I had to eventually bring out the manual to convince him. Luckily he wasn't working on my engine. Alfa's are not common here at all.
When he walked away he was still scratching his head literally trying to figure out how that sequence works!

Thanks

Chris
Guy Croft
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Re: Choosing a new exhaust manifold

Post by Guy Croft »

Can you publish here a sketch of the engine in plan view with FW end marked and cylinder nos correctly oriented please, just for the record. Also publish the firing order.

Thanks,

G
Brit01
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Joined: June 28th, 2011, 4:54 pm
Location: Uruguay

Re: Choosing a new exhaust manifold

Post by Brit01 »

Here's a quick sketch of a top view of the block and the firing sequence of the pistons.
1-3-2-4

Regards,

Chris
Attachments
firing sequence b.JPG
firing sequence b.JPG (15.96 KiB) Viewed 5093 times
Guy Croft
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Joined: June 18th, 2006, 9:31 am
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Re: Choosing a new exhaust manifold

Post by Guy Croft »

You'd have to crossover unless you use a works style system with such (very) long primaries that they will function with effective separation.
Brit01
Posts: 825
Joined: June 28th, 2011, 4:54 pm
Location: Uruguay

Re: Choosing a new exhaust manifold

Post by Brit01 »

You'd have to crossover unless you use a works style system with such (very) long primaries that they will function with effective separation.
Long primaries like the ones shown in the original photo on page#1?

Also Alfa introduced the crossover when they came out with the 16v model, very soon thereafter many companies began making the crossover for the 8v model due to the demand after people experienced the performance difference.

Thanks

Chris
Guy Croft
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Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
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Re: Choosing a new exhaust manifold

Post by Guy Croft »

Yes Chris, I think you have the general idea,

G
Brit01
Posts: 825
Joined: June 28th, 2011, 4:54 pm
Location: Uruguay

Re: Choosing a new exhaust manifold

Post by Brit01 »

When I have time in the next couple of weeks I'll visit one local specialist I know with some drawings and dimensions/photos to see what they can come up with and at what price.

Thanks as always.

Have a good weekend.

Chris
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