1007cc motor questions...

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Fast Eddie

Fast Eddie

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Ladies,
Was jus' wundrin' if any of you out there who have played with a 1007 motor could share your knowledge on the following:
Is it possible to retain the squish band (which will be quite large on an 83mm bore) and have a reasonable compression ratio?
What sort of compression ratios have people run?
Are they as impossible to kick start as legend suggests?
Can we see some dyno data?
Can anyone give us some riding impressions?
 
I seem to remember comnoz posting a thread of a 1007 cc engine that he built for a customer who put it into a P11. Jim had it on his dyno and posted the numbers etc. Unfortunately I don't remember the name of the article as it was posted, but I think it was mid to late last year so should pop up on a search.
 
Just found the article. It's a thread titled "tomorrow looks like fun"......but it was posted in july of 13........my how time flies :shock:
 
Nigel, don't do it, you know I'll be extremely jealous :mrgreen: :mrgreen: :mrgreen:
 
Thanks for finding the link CJ, I have read through it before, but enjoyed it again!

The trouble is, like a lot of really interesting projects that show up as threads on here, it stopped a long time ago and we never got to hear how things developed, evolved, and generally 'panned out'.

Hence my question, I'm hoping to hear from folk who have put some miles on...

Martin, don't get too excited, I'm only scheming at the moment. But the thing is, if you build a big, hot and 'safe' motor, ie Maney barrls, cases and crank etc... You've already spent the cash that cudda built you a 1007 lump! When you really look at the kit Steve sells, and the ridiculous power and torque increase it gives... It is actually bloody good value for money! I guess the trouble is that EVERYTHING else would need upgrading, TTI box etc, pushing the real build cost a lot higher.

No Glen you can't have my old motor! Even if I do go this route (and its a very big IF) I'd still want my current lump under the bench as 'back up'!
 
Fast Eddie said:
Ladies,

Is it possible to retain the squish band (which will be quite large on an 83mm bore) and have a reasonable compression ratio?
What sort of compression ratios have people run?
Click to expand...

Bit confused by this question Nigel, I would have thought your biggest problem was making sure you kept the compression down to a level that would work with pump petrol?

I am sure Steve cann clarify what compression he expects from his own pistons after he had modded the head for bolt positions and squish...

But surely if you went to all that expense you would want lightweight pistons and rods (or expect a motor that may not rev to your requirements :wink: )....

Jim Schmitt flat top pistons have the potential for 12:1, with a squish band cut to suit the pistons.....
 
SteveA said:
Fast Eddie said:
Ladies,

Is it possible to retain the squish band (which will be quite large on an 83mm bore) and have a reasonable compression ratio?
What sort of compression ratios have people run?
Click to expand...

Bit confused by this question Nigel, I would have thought your biggest problem was making sure you kept the compression down to a level that would work with pump petrol?

I am sure Steve cann clarify what compression he expects from his own pistons after he had modded the head for bolt positions and squish...

But surely if you went to all that expense you would want lightweight pistons and rods (or expect a motor that may not rev to your requirements :wink: )....

Jim Schmitt flat top pistons have the potential for 12:1, with a squish band cut to suit the pistons.....
Click to expand...

The question is aimed at understanding how to get the best of both worlds really, ie workable CR and a squish even with such a big lump. I'm thinking that 12.:1 + 1007cc + kick start + maintianing healthy limbs is not a good combo !!

But it seems keeping the squish with a lower CR might just be 'a bridge to far'...

I spoke to Steve, who rather interestingly reckons that dishing the pistons on these big motors to achieve a squish with a lower CR doesn't work very well, as it leads to incomplete combustion. He recommends a flat top piston machined down and / or barrel spaced to give a 9.5:1 ish CR, and says that this will work fine with premium unleaded pump fuel.

And yes, given how well the long rod / light piston combo seems to work in my 850, I would certainly want this in a bigger motor, in fact, the increased stroke would be an argument even stronger for longer rods to create a 'nicer' rod / stroke ratio.

But like I said, I'm only pondering, so don't hold your breath waiting for progress on this one ...
 
SteveA said:
............But surely if you went to all that expense you would want lightweight pistons and rods (or expect a motor that may not rev to your requirements :wink: )....

Jim Schmitt flat top pistons have the potential for 12:1, with a squish band cut to suit the pistons.....
Click to expand...
Good point about the jsmotorsports pistons and rods they would seem like a "must" for a build like this SteveA, . Jim posted a thread a while back about the 1007 race bike that picked up something like a 1000 rpms on top , and rev'd much more freely than they were able to get the engine to spin, prior to installing the lightweight hardware. Not sure if I'm remembering correctly or not, but I think they had the complete jsmotorsports valve train to complement the longer rods and pistons, anyway they seemed to have won a bunch of races. As for the 12:1 compression ratio that's up there in Brittens territory, he made crazy power from his twins didn't he :D . Not sure how a norton would hold up under those conditions though.......which get us back to the original posters question of feedback from someone with first hand experience which means I need to bow out at this point.
 
When I was planning my build I spoke to Steve about a 1007 motor. It was him who put me off, saying it would be difficult to start. At 6' 1" & 14 stone I don't struggle to start anything, but had wondered about starting 1007 ccs. The other thing which put me off was the feeling that it was a step too far. After all it's the same set of main bearings as the original 500 engine. Also, to get the best power the head needs welding up & modifying to stage 3 spec. (another grand plus VAT) If Steve (or Fullauto) made a new head specifically for a bigger capacity, cases with beefier mains & a suitable electric start, then I might consider building one. Although having just bought a Buell XB12R which I think is the nearest thing to a modern Commando available, even this is unlikely. The Buell has 91 bhp at the rear wheel, two big cylinders, a rubber mounted engine to which the swing arm is attached, & truly fabulous handling. All for less than the price of a 1007 kit.
Still madly in love with the 920 though.

Martyn.
 
Matchless said:
When I was planning my build I spoke to Steve about a 1007 motor. It was him who put me off, saying it would be difficult to start. At 6' 1" & 14 stone I don't struggle to start anything, but had wondered about starting 1007 ccs. The other thing which put me off was the feeling that it was a step too far. After all it's the same set of main bearings as the original 500 engine. Also, to get the best power the head needs welding up & modifying to stage 3 spec. (another grand plus VAT) If Steve (or Fullauto) made a new head specifically for a bigger capacity, cases with beefier mains & a suitable electric start, then I might consider building one. Although having just bought a Buell XB12R which I think is the nearest thing to a modern Commando available, even this is unlikely. The Buell has 91 bhp at the rear wheel, two big cylinders, a rubber mounted engine to which the swing arm is attached, & truly fabulous handling. All for less than the price of a 1007 kit.
Still madly in love with the 920 though.

Martyn.
Click to expand...

Several good points there Martyn!

Are your pistons dished to keep the squish band and lower the CR? What CR are you running?

Your size and shape is not dissimilar to mine, how is the XB12R for size? A mate had an X1 a while back which was a pretty good ride. I guess the XB12R is similar, but more ?!
 
Hi Eddie,
The pistons are medium comp. flat top with valve cut outs as supplied by Jim Schmidt. I skimmed the head by .025" or .030" & used a .020" head gasket to get 8.9 to 1. Jim told me the pistons would give 9 to 1 but this is not the case. If I was building it again I would buy the high comp. pistons & machine them to suit.
The Buell is a good fit for me. So far I have only had a short ride of 120 miles. The biggest problem is the fuel capacity which is poor to say the least. The frame only holds 3.7 US gallons. I can forgive this though because it is such a hoot to ride, as indeed it should be with a 52" wheel base, 21* rake, & 3.3" of trail. NICE!
 
Matchless said:
Hi Eddie,
The pistons are medium comp. flat top with valve cut outs as supplied by Jim Schmidt. I skimmed the head by .025" or .030" & used a .020" head gasket to get 8.9 to 1. Jim told me the pistons would give 9 to 1 but this is not the case. If I was building it again I would buy the high comp. pistons & machine them to suit.
The Buell is a good fit for me. So far I have only had a short ride of 120 miles. The biggest problem is the fuel capacity which is poor to say the least. The frame only holds 3.7 US gallons. I can forgive this though because it is such a hoot to ride, as indeed it should be with a 52" wheel base, 21* rake, & 3.3" of trail. NICE!
Click to expand...

Thanks Martyn.
BTW... Are you going to Beezumph?
 
Yes. The wife & myself will be in Louth on Friday evening & at Cadwell all day Saturday.
Hope to see you there.

Martyn.
 
Matchless said:
Yes. The wife & myself will be in Louth on Friday evening & at Cadwell all day Saturday.
Hope to see you there.

Martyn.
Click to expand...

I'll be there with my Commando (metallic blue, Roadster tank, clip ons & Rearsets) and Vincent (black, obviously!) and a rental van (transportation, workshop and accommodation).

How will I know / find you?
 
I'm early twenties, sophisticated jet setter & will be wearing red Carnation in button hole.........just kidding. I've got long grey hair & Carolyn has long red hair. We might come on the O.I.F triple or the 920 Commando, not sure yet. We will probably find you. Can't miss a shiny Commando & a Vincent parked together.
 
cjandme said:
SteveA said:
............But surely if you went to all that expense you would want lightweight pistons and rods (or expect a motor that may not rev to your requirements :wink: )....

Jim Schmitt flat top pistons have the potential for 12:1, with a squish band cut to suit the pistons.....
Click to expand...
Good point about the jsmotorsports pistons and rods they would seem like a "must" for a build like this SteveA, . Jim posted a thread a while back about the 1007 race bike that picked up something like a 1000 rpms on top , and rev'd much more freely than they were able to get the engine to spin, prior to installing the lightweight hardware. Not sure if I'm remembering correctly or not, but I think they had the complete jsmotorsports valve train to complement the longer rods and pistons, anyway they seemed to have won a bunch of races. As for the 12:1 compression ratio that's up there in Brittens territory, he made crazy power from his twins didn't he :D . Not sure how a norton would hold up under those conditions though.......which get us back to the original posters question of feedback from someone with first hand experience which means I need to bow out at this point.
Click to expand...

That 1000cc race bike belonged to Dave Watson and was ridden by Gary Thwaites. It had the lightweight pistons/long rods with approx 12:1 C.R. and a JS3 cam which gave it another 1300 RPM over the heavy long skirt pistons and after that it finished and won all its races in 2012 in the UK. Using Castor R40 oil there was no measurable wear at the end of the season. More info at:
http://www.jsmotorsport.com/technical_success.asp

"Dances with Shrapnel" has the Seeley street version of the 1000 Norton with the same pistons/rods but with milder compression and a D+ cam which is the same as the JS3 but for stock flat lifters.
 
jseng1 said:
cjandme said:
SteveA said:
............But surely if you went to all that expense you would want lightweight pistons and rods (or expect a motor that may not rev to your requirements :wink: )....

Jim Schmitt flat top pistons have the potential for 12:1, with a squish band cut to suit the pistons.....
Click to expand...
Good point about the jsmotorsports pistons and rods they would seem like a "must" for a build like this SteveA, . Jim posted a thread a while back about the 1007 race bike that picked up something like a 1000 rpms on top , and rev'd much more freely than they were able to get the engine to spin, prior to installing the lightweight hardware. Not sure if I'm remembering correctly or not, but I think they had the complete jsmotorsports valve train to complement the longer rods and pistons, anyway they seemed to have won a bunch of races. As for the 12:1 compression ratio that's up there in Brittens territory, he made crazy power from his twins didn't he :D . Not sure how a norton would hold up under those conditions though.......which get us back to the original posters question of feedback from someone with first hand experience which means I need to bow out at this point.
Click to expand...

That 1000cc race bike belonged to Dave Watson and was ridden by Gary Thwaites. It had the lightweight pistons/long rods with approx 12:1 C.R. and a JS3 cam which gave it another 1300 RPM over the heavy long skirt pistons and after that it finished and won all its races in 2012 in the UK. Using Castor R40 oil there was no measurable wear at the end of the season. More info at:
http://www.jsmotorsport.com/technical_success.asp

"Dances with Shrapnel" has the Seeley street version of the 1000 Norton with the same pistons/rods but with milder compression and a D+ cam which is the same as the JS3 but for stock flat lifters.
Click to expand...

The JS3 is a rather aggressive cam isn't it Jim? I thought they were mainly aimed at motors wanting extreme high revs... so am wondering why one would want one in such a big motor. Can you enlighten please ?
 
The bigger your motor the more cam you need. A bigger motor with the same cam will have more low end torque and less top end. So a JS3 is not extremely radical in a 920 or a 1000. Think in proportions. The same applies to ports and exhaust. When I switched to an 850 I was disappointed - lots of bottom end but nothing more on top. My lap times didn't improve until I calculated the percentage difference between a 750 and an 850 and increased all my 750 port, exhaust specs and everything else in proportion until I had the same power band for the 850.

I haven't personally tested a JS3 cam in a 1000 on the street so I can tell you about the power band. But you would for sure want a JS3 in a 1000 on the track and nothing less.

I forgot to mention that the Dave Watson racer had a Maney stage 3 head.
 
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