paulf
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| posted on 17/8/04 at 09:47 PM |
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Crossflow safe revlimit?
What is the maximum safe rev limit for a crossflow running standard valve gear and fitted with 1300 pistons, the cam is uprated but I do not know what
with.
It is a little flat at the bottom end but pulls strongly from 3500 to7000 revs .However i am a little unsure about reving it past 6000 as i do not
want to damage the bottom end.
What is a recomended safe revs to use for a standard crank and rods?
Paul.
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Mark Allanson
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| posted on 17/8/04 at 09:57 PM |
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my old 1300 gt mk1 (I was 19!!) went yellow at 5500 and red at 6000.
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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paulf
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 posted on 17/8/04 at 10:05 PM |
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I had set myself a rev limit of 6000 but now i am starting to get carried away abit and finding myself reving to 7000 ocasionally as it seems happy to
do so.
I just dont want to blow it up before the winter .
quote:
Originally posted by Mark Allanson
my old 1300 gt mk1 (I was 19!!) went yellow at 5500 and red at 6000.
 
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zilspeed
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| posted on 17/8/04 at 10:17 PM |
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The main factor in a crossflow is the weight of the pistons - they've got to be big enough to accomodate a combustion chamber - unless
they're flat topped and running down the bore and / or a chambered head.
I wouldn't go much over 6500 to be honest. Sometimes circumstance affect this though. The last corner at Forrestburn hillclimb is 2nd gear for
me and if I changed gear at 6500 that would be just before the finish line, so it's probably best to hang onto the lower gear.
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SeaBass
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| posted on 18/8/04 at 07:32 AM |
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Funny you should say that Zilspeed. I've been to lots of the Hillclimbs at Forrestburn and I'm hopefully marshalling this weekend. Nearly
all cars that blast out of Summit along the finish straight seem to hit the limiter. Great for people on the bank!
I've not taken my X-flow past about 6k for fear of it exploding. But it'll happily cruise along the motorway at about 5k for hours on
end!
Zilspeed - are you going to the Gymkhana/Grass Autotest at Broxburn 12th September? Great Fun!!
Photos of Last Monklands Autotest here...
Cheers
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Rob Lane
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| posted on 18/8/04 at 07:49 AM |
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With standard valve gear 6500 is upper limit BUT I would shift at 6-6200 for longer engine life with road use.
Valve gear is the first weak point on a xflow. A new rocker shaft with all the gubbins, spacers to replace springs etc are needed for reliability.
Trouble is pushrods then are the weak point.
7000rpm will knacker engine quickly even with a good build. Repeated use asks for a rod to say hello to side of block at some point!
Been there, done that, many times!
Now 4age engine with 8000rpm limit.
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colibriman
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| posted on 18/8/04 at 07:59 AM |
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quote:
Nearly all cars that blast out of Summit along the finish straight seem to hit the limiter.
the thing is your shaking with the joy of getting round by that point.....you maybe hardly notice the rev limit.....your in sight of the line!
quote:
Great for people on the bank!
yep....unless its the usual forrestburn rain !
oh....and talking of forrestburn and sprints....one of my engines will be in one of the top single seaters next year....GSXR1000 left me yesterday
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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zilspeed
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| posted on 18/8/04 at 09:51 AM |
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Jonathan Rarity ?
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zilspeed
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| posted on 18/8/04 at 09:53 AM |
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quote:
Originally posted by SeaBass
Zilspeed - are you going to the Gymkhana/Grass Autotest at Broxburn 12th September? Great Fun!!
Photos of Last Monklands Autotest here...
Cheers
I think I will. I was talking to Ian Scoular at the weekend - his sonMark was there with the Sylva Striker. He said they had a great time.
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paulf
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| posted on 18/8/04 at 10:24 AM |
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Thanks for the replys.
I suspected 6500 to be maximum safe revs , I will have to try and not get carried away in future, i want it to last until I am ready to install my
blade engine , then i will be able to really rev it.
Paul.
quote:
Originally posted by Rob Lane
With standard valve gear 6500 is upper limit BUT I would shift at 6-6200 for longer engine life with road use.
Valve gear is the first weak point on a xflow. A new rocker shaft with all the gubbins, spacers to replace springs etc are needed for reliability.
Trouble is pushrods then are the weak point.
7000rpm will knacker engine quickly even with a good build. Repeated use asks for a rod to say hello to side of block at some point!
Been there, done that, many times!
Now 4age engine with 8000rpm limit.
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colibriman
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| posted on 18/8/04 at 04:37 PM |
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Zil.....
better not say.....forgot to ask if it was to be common knowledge or not......
cheers
Colin
you still interested in an engine?...maybe a zx10 coming in...
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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zilspeed
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| posted on 18/8/04 at 06:04 PM |
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Oh that's fine.
But I subscribe to the bike engined cars mailing list, and certain people are interested in whether or not a GSXR1000 engine needs beffled when
mounted in a single seater 
Yeah of course I'm interested in an engine. Don't worry, I keep an eye on your listings of stock. As soon as I'm in a position to
bite, you'll be the first to know.
Nobody is cheaper or more local, so that's a no brainer for me. You'll be the man.
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colibriman
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| posted on 18/8/04 at 06:15 PM |
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quote:
But I subscribe to the bike engined cars mailing list, and certain people are interested in whether or not a GSXR1000 engine needs beffled when
mounted in a single seater
........McStig IS big brother.....
I know, I noticed that same interest....but then I have biased information knowing what may (or may not) be behind it....
gimme a shout when your ready to bite....
Paulf....
sorry for sidelining in your thread !
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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ernie
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| posted on 18/8/04 at 06:56 PM |
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rev limit
I have just had a 1300 engine built by Vulcan which includes steel rocker posts with a rev limit of 7000 once run in. Is there any point of going
above 6500 if the cam peaks at it
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paulf
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| posted on 18/8/04 at 08:35 PM |
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There is no point in exceeding the cams maximum power revs but my engine appears to have a hotter cam.I dony know what it is as i bought the engine as
a runner and fitted it as it was.
Paul
quote:
Originally posted by ernie
I have just had a 1300 engine built by Vulcan which includes steel rocker posts with a rev limit of 7000 once run in. Is there any point of going
above 6500 if the cam peaks at it
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