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Post by pasis on May 28, 2013 17:19:44 GMT
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Post by nitro on May 28, 2013 17:19:50 GMT
I forgot - AFR was 11,5.
Stock CR of 1074 is 11,5:1! So minimum spacer for reliable 12psi is 2mm with 2 foot spacer IMO. It will bring you down to appr. 8,5:1. Don´t forget it´s still cast pistons! Forged one I think 9:1 is the way to go. Fat mixture and less advance would also be a good idea.
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Post by mattturbocar on May 28, 2013 17:21:39 GMT
gsf1250s block has a couple of the long through bolts in a slightly different place (maybe 5mm different). The locating dowels are also different. The cam chain tensioning is slightly different too, but that is a detail.
I bought one to investigate (ages ago) and intend to modify it, but haven't yet found the time.
What is good about the 1250 block is that the liners for cyls 1&2 are made as a single component, so that should help the gasket in that area.
If you use the 1250s pistons then you need Gen2 busa conrods to match the piston pins and crank of the 1100wp.
Maybe I should build that up instead if I am going to have to install a spacer I might as well go all out. Not sure, I would like to be out enjoying the sun and saving engine building for the winter.
Matt
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Post by pasis on May 28, 2013 17:24:28 GMT
I think the standard pistons shit. And do not stand much boost pressure (0.4-0.5 max). You must use special turbo pistons.
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Post by pasis on May 28, 2013 17:27:14 GMT
If I put a block on the bandit, then I'll leave my 79.5mm pistons. With a cast iron sleeve in the block.
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Post by mattturbocar on May 28, 2013 17:31:42 GMT
I forgot - AFR was 11,5. Stock CR of 1074 is 11,5:1! So minimum spacer for reliable 12psi is 2mm with 2 foot spacer IMO. It will bring you down to appr. 8,5:1. Don´t forget it´s still cast pistons! Forged one I think 9:1 is the way to go. Fat mixture and less advance would also be a good idea. Sounds like a plan. I have a 3mm spacer kicking around, so if I junk the base spacer that will pretty much give me what you are suggesting. I can set it up a bit rich (13.5 and down to 12 on boost, and never weaker than 14.7). I've already mapped the advance to drop-off with boost (down by 8deg at 12psi). Now to get into the shed and make it happen! Thanks guys
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Post by pasis on May 28, 2013 17:37:39 GMT
Hope enough chain length with 3 mm spacer.
AFR with a turbo should be around 11-11.5
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Post by mattturbocar on May 28, 2013 17:44:54 GMT
I think the standard pistons shit. And do not stand much boost pressure (0.4-0.5 max). You must use special turbo pistons. Bad news that. They don't look like much, but I am a sort of build it and hope sort of guy.
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Post by pasis on May 28, 2013 17:48:21 GMT
You can try to use the pistons from a bandit 1250+spaicer, but they are 79mm. Since the turbo can also be a problem. About a week later I get a 77mm turbo pistons mts. I'll post photos of them here.
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Post by nitro on May 29, 2013 9:07:22 GMT
3mm is safer for this boost level. Depending on how much foot spacer you use its 7.7 – 8 : 1.
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Post by katana on May 29, 2013 9:17:18 GMT
VP is a range of Racing Gasoline / Petrol...... C12 is a leaded blend that will get around 112 octane. VP is an interesting site to look at - learn't a lot there!
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Post by mattturbocar on May 31, 2013 8:15:53 GMT
So, took it apart (never opened up an engine before that wasn't broken), and put in a 3mm base spacer on its own with a little bit of sealant. Looks like it hadn't come apart before.
Can I reuse the head gasket?
It looks fine, only thing is some of the rubberized stuff has stuck to the head faces. I've reused these things before (actually the only time I bought I new one it gave me problems). What do you think?
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Post by nitro on May 31, 2013 10:46:31 GMT
My 1100W Bi-Turbo is also 1117cc (77mm piston) with stock sleeves. It keeps perfect. But I build last winter a second engine with 1089cc (76mm) for more reliability. The 1117 I will put into my drag bike. Both have JE turbo pistons and Carrillo rods.
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Post by nitro on May 31, 2013 10:47:49 GMT
My 1100W Bi-Turbo is also 1117cc (77mm piston) with stock sleeves. It keeps perfect. But I build last winter a second engine with 1089cc (76mm) for more reliability. The 1117 I will put into my drag bike. Both have JE turbo pistons and Carrillo rods. Ups - forgot the second side
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Post by mattturbocar on Jun 3, 2013 13:08:01 GMT
Engine out, 3mm spacer swapped in, NEW headgasket fitted, camchain just long enough, cams timed (inlet was at 125deg, exhaust at 108; set them both to 108). 1074cc engine fitted.
I need to finish moving over all the ancillaries tonight (water hoses, inlet manifold, exhaust manifold) bung some fluids in and and make up a new copper turbo gasket. Hopefully finish before the good weather does.
Matt
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