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Post by danm54 on Feb 4, 2015 21:05:32 GMT
I'm about ready to set my cams up and I'd like some advice on where to start.
Running stock cams on a game 1100w
Does the standard timing work well when boosted or would it favor being altered?
Also, what's the best procedure to correctly set the timing?
Cheers
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Post by arttu on Feb 5, 2015 6:14:34 GMT
I would start with stock timing. But I would check it really is what Suzuki specifies because it can be quite badly off if you just trust on factory timing marks.
Altering the timing from stock may give some benefits on boosted engine but I don't think there is any universal truth what would be the best timing. As far as I know it depends greatly on various details of the setup like turbo sizing and so on. I have understood that if the turbo is large enough to keep exhaust back pressure on reasonable level (not much higher than boost) then cam timing works pretty much like on NA engine. But if the exhaust side of the turbo is restrictive it might be beneficial to reduce overlap. Any way, I have done some experiments with this and while altering the timing made some difference it wasn't very dramatic. So I would say that you can't go badly off with standard timing and it should be safe starting point.
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Post by danm54 on Feb 5, 2015 21:45:14 GMT
Cheers,
Got slotted sprockets so can make sure it's right.
How do I set the cams correctly?
I'll set it up to the timing marks but I don't know how to make sure it actually right.
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Post by screwriverracing on Feb 5, 2015 22:34:59 GMT
You will need a dead stop and degree wheel and dial gauge.
First find TDC then measure the cam at 10 thou open take reading then measure at 10 thou before closed, I've forgotten the rest.
Think theres something on you tube from APE on how to do it, if not someone will be along shortly to correct me, lol.
Cheers SRR
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Post by arttu on Feb 6, 2015 4:47:07 GMT
Yes, there are plenty of instructions for degreeing the cams on the web. Here is one that I found by a quick search: www.cranecams.com/uploads/instructions/803_.pdfIt's for car engines but it seems to have all essential steps described clearly. |
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Post by danm54 on Feb 6, 2015 19:36:32 GMT
Cheers, it's not something I've done before and I don't always trust what Google brings up!
Shouldn't be too hard once I get started.
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Post by nitro on Feb 17, 2015 14:28:40 GMT
Stock timing of 1074 is shit. You can keep intake cam, but exhaust cam is much to late. IMO
May be, you can move from 103° (stock) to 110° LC...
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Post by danm54 on Feb 22, 2015 18:18:55 GMT
I'm not sure if I'm doing this right.
I've set the cams up using the marks on the end of the cams. I've found tdc and set the cam sprockets up as the manual says.
I've then rotated the cams so the marks line up on the head and tightened the cam sprockets up.
If the exhaust cam needs to be advanced 7 degrees of crank rotation then if I find 7 degrees before tdc can I then just rotate the exhaust cam forward to line the mark up?
That might not seem the best way but the exhaust cam is only just opening at 110 so I don't think I fully understand it.
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Post by duckndive on Feb 22, 2015 22:53:05 GMT
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Post by danm54 on Feb 22, 2015 23:14:00 GMT
That makes sense now, I see exactly how the 0.50 opening is measured. I was thinking it was measured off the cams which didn't make sense.
I'll have another look at it tomorrow.
Cheers
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Post by danm54 on Feb 23, 2015 21:05:41 GMT
So if I've done this right these are my cam specs
Overlap: 26.00 degrees
Intake Duration: 235.00 degrees
Exhaust Duration: 226.00 degrees
Intake Installed Centerline of 96.50 degrees ATDC.
Exhaust Installed Centerline of 108.00 degrees BTDC.
Now I haven't altered anything since I set them to the marks.
Should I aim to get the exhaust dead on 110?
And what is the standard intake timing? Can't seem to find the info in the manual.
Cheers
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Post by katana on Feb 24, 2015 17:01:39 GMT
You won't usually find timing quoted - they give you marks so that should be adequate! Best you'll find 'maybe' is a diagram showing opening and closing angles related to TDC / BDC!
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Post by danm54 on Feb 25, 2015 21:37:12 GMT
Yea I can't find anything!
How accurate are the marks going to be? The lines on the end of the cam are only lined up by eye.
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Post by nitro on Feb 26, 2015 14:47:26 GMT
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Post by danm54 on Feb 26, 2015 18:38:29 GMT
Cheers Nitro, found it in the manual now!
It does however appear that I don't have a stock intake cam installed, it has C marked on the end which it should be A, B or blank. It is marked as an intake cam though.
From a quick measure it has the same lift but seems to have a more rounded profile, it's 1.2mm wider across the narrow part of the cam.
Opens at 21 BTDC
Closes at 33 ABDC
It's probably came from the side car engine I had so I guess its better for a N/A engine. Not sure whether its better for a turbo or not.
I do have a stock intake cam but its not in quite as good condition.
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