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AP996

Should leave it alone, but

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AP996

After getting pretty good results with some fairly simple intake mods I’ve now got the bug and want more so just got another set of throttle bodies bored out.

B2D03E5B-3270-4331-B664-7B4F39993E6A.thumb.jpeg.e94ed9eff5f35053fe9654c66d9dac27.jpeg

Picked them up for a mere £30 including a standard airbox and then a friend of a work colleague bored them for another £30 so not a lot of cash invested. Don’t expect to gain much until the cylinder head ports are opened up to match so that leads to another purchase, was looking for a cylinder head and cams but ended up buying another complete engine. Supposed to be a 9000 mile engine but will see what it’s like when I pull it apartDCE9AE71-9493-4898-A13F-4CC569404D45.thumb.jpeg.c253598ce3f7232d237804f8084e3545.jpeg

Plan to port the head and get the cams ground as a minimum.

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Joaoduarte
2 hours ago, AP996 said:

After getting pretty good results with some fairly simple intake mods I’ve now got the bug and want more so just got another set of throttle bodies bored out.

B2D03E5B-3270-4331-B664-7B4F39993E6A.thumb.jpeg.e94ed9eff5f35053fe9654c66d9dac27.jpeg

Picked them up for a mere £30 including a standard airbox and then a friend of a work colleague bored them for another £30 so not a lot of cash invested. Don’t expect to gain much until the cylinder head ports are opened up to match so that leads to another purchase, was looking for a cylinder head and cams but ended up buying another complete engine. Supposed to be a 9000 mile engine but will see what it’s like when I pull it apartDCE9AE71-9493-4898-A13F-4CC569404D45.thumb.jpeg.c253598ce3f7232d237804f8084e3545.jpeg

Plan to port the head and get the cams ground as a minimum

Hmm wich simple intake mods you Made ?

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AP996
19 hours ago, Joaoduarte said:

Hmm wich simple intake mods you Made ?

Nothing different to what you’ve already seen, airbox removed, shortened intakes and bell mouths.

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AP996

Got around to pulling the top of the engine at the weekend, before the head came off I checked the standard cam timing, numbers I got were (with valve 1 mm open)

Exhaust cam, valves open at 37 degrees before BDC, closes at 5 degrees before TDC

Inlet cam, valves open at 5 degrees after TDC, closes at 35 degrees after BDC

been a long time since I did this sort of thing so if you think those numbers look wrong speak up😀A11B19FB-2458-4D2F-ADA1-94730476A488.thumb.jpeg.8edb52d73e2106783f5f4194a972b560.jpeg

checked squish clearance with solder and got 0.85 mm (34 thou) at tightest point, anybody out there willing to say how tight you can run these motors?

Only thinner head gasket I’ve seen advertised is the Spears racing one but that looks too thin at 10 thou.
 

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Joaoduarte

So mate any news about it? 

You got that throttle bodies bored out but the throttle plate is the standart one?

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AP996
6 hours ago, Joaoduarte said:

So mate any news about it? 

You got that throttle bodies bored out but the throttle plate is the standart one?

That’s right the throttle plates are standard, the bodies are just bored out where they narrow after the plates.

Not had much spare time due to work commitments but the cylinder head is away being ported, the same work colleague who organised the throttle body machining offered to do the porting so I’ve gone with it. I’m thinking at the moment that I will probably just do the head and the inlet cam, the inlet cam is very mild and actually has less lift and duration than the exhaust. I’ve looked into getting a slightly thinner head gasket, Vesrah in Japan make a gasket 0.5mm thick (0.6 standard), unfortunately they have no stock and they have a minimum order of 2 with a 40 day wait, having to buy 2 and shipping costs, tax’s etc make that uneconomic.

I made enquires with Kent cams and Newman cams, Newman are yet to reply but Kent cams have a regrind that gives 8.40 mm lift and 234 degrees duration at 1mm open.
Hordboy achieved good power without losing the nice midrange power these engines have with just the inlet cam modified so that looks like a good way to go for a bike thats used mainly on the street.

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Joaoduarte

I remembered your work because of a mt07 from thailand with bored throttle bodies iam going to post link to the video he got really good results by boring the throttle bodies

You incread the throttle bodies in the entrance from the airbox and in the exit to the head? You increased it by how much?

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AP996
22 hours ago, Joaoduarte said:

You incread the throttle bodies in the entrance from the airbox and in the exit to the head? You increased it by how much?

Throttle bodies are stock size on the airbox side, they are opened up to 38mm on the engine side to match the diameter at the throttle plate. There’s quite a restriction on the engine side as stock.

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