Rattle sound from r/h side of engine

iansoady
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Re: Rattle sound from r/h side of engine

Postby iansoady » Sun Feb 25, 2018 10:03 am

Hi Dennis.

The pistons I got from Keith came with the correct gudgeon pin bushes. These did need a light skim with the reamer but then so would new standard bushes (at least most of the time).

I found performance fine without any mods (mine had the 10:1 heads) but then I didn't have much to compare it with.

I used Nametab engineering in Redditch to do my rebore and was very happy with the job. I went for a bore on the upper end of the tolerance as I didn't want to spend the next few years running in......
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Re: Rattle sound from r/h side of engine

Postby Dennis.rose » Sun Feb 25, 2018 4:17 pm

Hello Brian , I agree by not skimming the barrels I'll be down on power , a good idea as a temp fix , the head gasket is quite thick .i think I may get all the work at the same time , I don't think it will be cheap though , cheers , Dennis

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Re: Rattle sound from r/h side of engine

Postby Dennis.rose » Sun Feb 25, 2018 4:31 pm

Hello Ian,thanks again for your advice, is +40 thou the upper end of the tolerance to do my rebore , I have 10 to 1 heads , what's your advice about cutting and porting the barrels with the Suzuki Pistons , this has thrown my plans upside down for tuning , any help any one , cheers , Dennis

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Re: Rattle sound from r/h side of engine

Postby bh.sprint » Sun Feb 25, 2018 7:12 pm

Hello Dennis,

Attached some measurments from Ron at Fahron engineering, he says these give an increase in power but do not make the engine intractable. These are based on the Ariel pistons.
With the Suzuki pistons the top to gudgeon pin is shorter and the skirt is shorter so you end up with timings similar to these. Generally the Suzuki pistons enable the engine to buzz/rev more.
If I can find a pair of pistons ,one Ariel and one Suzuki I'll post a picture so you can see the difference.

Brian H.
Attachments
timings for Ariel engine..jpg

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Re: Rattle sound from r/h side of engine

Postby Dennis.rose » Mon Feb 26, 2018 3:52 pm

Hi Brian , many thanks for your help and diagram , it will be good to see the difference between the Suzuki and Ariel Pistons , and if there is any difference in weight .
This Ariel forum is awesome , I'm new to it and had so many offers of help , be glad when I can help someone in return , cheers , Dennis

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Re: Rattle sound from r/h side of engine

Postby iansoady » Mon Feb 26, 2018 4:14 pm

Hi Dennis.

When I mentioned the tolerance I was talking about the clearance between the piston and bore. The Ariel workshop manual states this as 0.002" - .0035" when new: I had the rebore done to a clearance of .004" ie half a thou more than the maximum new clearance. As a rebore is advised when wear reaches .0035" (ie total clearance of .007") I felt this was OK and so it proved.
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Re: Rattle sound from r/h side of engine

Postby bh.sprint » Mon Feb 26, 2018 9:45 pm

Hello Dennis,

The picture of the two pistons- both standard size, rings but no g/pin -- weight Suzuki =135 gms
Ariel = 139 gms ( the bottom of the piston window has been removed)

I tried another piston std size but with brass g/pin inserts - weight 152 gms, I think there is some variation between piston weights.

You can see the piston top difference and the shorter skirt approx .125'' or 3 m/m.

It's not easy to see but the Suzuki piston has a higher dome, the clearance between the head squish band and piston top needs to be a min of .040'' or 1 m/m. In practice most engines vary between .045'' and .055'' approx.

Regards Brian H. ps - an engine coming together and it fired after 4 kicks and ran with 2 more.
Attachments
DSC02498.JPG
IMG_0442 (2).JPG

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Re: Rattle sound from r/h side of engine

Postby AndyEames » Mon Feb 26, 2018 10:00 pm

Hi Brian. What are those conrods please ?
Andy

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Re: Rattle sound from r/h side of engine

Postby bh.sprint » Mon Feb 26, 2018 10:29 pm

Hi,

The con-rods are Suzuki 110 m/m long, Ron Philips suggested them. They are used with Honda TSX pistons to give a capacity of 267 cc.

Testing the engine, or a least getting it ready, it now has a Mikuni carb 28 m/m , and the bike nearer completion.

Brian H.
Attachments
DSC02866.JPG
DSC02551.JPG

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Re: Rattle sound from r/h side of engine

Postby Dennis.rose » Tue Feb 27, 2018 3:26 pm

Hello Brian , thanks for the information about the weight and size comparison between the Ariel and Suzuki Pistons , I can see the dome on the Suzuki . With bearing that in mind ,is it still advisable to also skim the heads as well as the barrels to obtain 12 :1 compression or do you think that's pushing it to far .well done with your engine rebuild , that started well after only 4 kicks . Did you do much work to your engine ? I like both those Ariels on your 1st attachment, could you show me more pictures of the arrow behind the leader please , from what I can see it looks awesome ,cheers , Dennis


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