Cock Wombles - cracked head

[Solcambs]

Started a 1216 and the 1100L motor I have has a number of issues with the cylinder head. repairable, but considering options to buy an 1100M/N cylinder head.  - does anyone know if the 1100M/N cylinder head bolts to the 1100L barrels? Anything worth mentioning?

Edited January 9, 2018 by Solcambs

[dupersunc]

They bolt on but cams and valve train are different.

I have a good 1200 bandit head here if it's any help.

[Solcambs]

39 minutes ago, dupersunc said:

They bolt on but cams and valve train are different.

I have a good 1200 bandit head here if it's any help.

II00L M or N for me ... L I can repair. M or N because they have a better port shape and will match the inlet side to the FCR carbs and 40mm rubbers. So I am having a cam grind .. how different are the cams? 

[Solcambs]

51 minutes ago, dupersunc said:

They bolt on but cams and valve train are different.

I have a good 1200 bandit head here if it's any help.

Ignore that --- just looked ... massively different cams :o( More money!! May have to invest time and repair the existing heads! 

[Gixer1460]

More performance cams available for the K / L heads - not so for the M / N's. The earlier heads inlet posts can easily be opened out to take 40mm inlets. The M port shape is better but its marginal in most applications. IMO 41 FCR's are too big for a 1216 unless its a full on screamer? Shim gap adjustment is a PITA as well!

[Solcambs]

1 hour ago, Gixer1460 said:

More performance cams available for the K / L heads - not so for the M / N's. The earlier heads inlet posts can easily be opened out to take 40mm inlets. The M port shape is better but its marginal in most applications. IMO 41 FCR's are too big for a 1216 unless its a full on screamer? Shim gap adjustment is a PITA as well!

Just had exactly the same thought process. Saw a N top end without cams but with valves train. Then thought about having to source cams, getting them matched, and while it has better port angles, but what's that worth in real money for the cost and pain of trying to source cams & shims etc. I reckon we'll repair the L cylinder head, added 40mm boots, and then open ports up to match the FCR39s - should work well enough, we are planning on port work anyhow ... fingers crossed the cracks are repaired well - but I'm confident we'll do it and cheaper than the alternative. Worth a bash before I go source another L cylinder head.

[Gixer1460]

Just out of interest where are the cracks? They mostly appear between the valve seats and valve seats and plug holes - in which case don't bother trying to repair as you'd need to replace the valve seats to do it properly - lot of work, effort and money and it'll probably crack again beside the welded section. Lots of engines run for years with extensive cracks without drama's.

[Solcambs]

4 minutes ago, Gixer1460 said:

Just out of interest where are the cracks? They mostly appear between the valve seats and valve seats and plug holes - in which case don't bother trying to repair as you'd need to replace the valve seats to do it properly - lot of work, effort and money and it'll probably crack again beside the welded section. Lots of engines run for years with extensive cracks without drama's.

Really ... I'll check again tomorrow ... we were talking about the crack coming from the valve seat ... but cannot remember where to. I'll get photos tomorrow. So if it is you describe, then leaving them with a 1216 doing say 150hp at the rear would be OK?

[dupersunc]

8 minutes ago, Gixer1460 said:

Just out of interest where are the cracks? They mostly appear between the valve seats and valve seats and plug holes - in which case don't bother trying to repair as you'd need to replace the valve seats to do it properly - lot of work, effort and money and it'll probably crack again beside the welded section. Lots of engines run for years with extensive cracks without drama's.

This.

[Gixer1460]

Seen the cracks on nitrous GSX's and GSXR's at around 300hp outputs - fairly extreme so 150hp shouldn't stress it IMO.

Edited January 10, 2018 by Gixer1460

[Solcambs]

11 hours ago, Gixer1460 said:

Seen the cracks on nitrous GSX's and GSXR's at around 300hp outputs - fairly extreme and 150hp shouldn't stress it IMO.

Here you - do you reckon these are OK to ignore then?

[Solcambs]

In another turn of events - I cannot see the engine at the mo ... we were discussing over the phone the relative merits of the L vs the M. Looks like the head has shims but has 36mm carb boots. ... so possibly an American M or N or a UK M or N which has had 36mm boots fitted at some point? ! Bloody hell I really should pay more attention - there's a moral in here somewhere! 1st job this morning is to work out which engine this is!

Edited January 10, 2018 by Solcambs

[370steve]

9 minutes ago, Solcambs said:

I there's a moral in here somewhere! 1st job this morning is to work out which engine this is!

THEN Take it out, throw it away and fit a 1157

Edited January 10, 2018 by 370steve

[Solcambs]

Just now, 370steve said:

Take it out, throw it away and fit a 1157

In my defence this is the first large bore Suzuki I have worked with that wasn't a 2 stroke. Much simpler those 2 stroke machines ... it's the future you know!

[Solcambs]

Well bugger me sideways ... it is an M/N head. Right ... contacting seller of and N head. Make sure that one is fine .. and we are good to go.

[Gixer1460]

4 hours ago, Solcambs said:

Here you - do you reckon these are OK to ignore then?

Yes.

[Solcambs]

7 hours ago, Gixer1460 said:

Yes.

I know I know ... spares are always good. New head is mint. So all good.

[Fula28]

That head with plug thread crack is usual and repairable! Quite common£80-100 to fix easy. But if it's not boosted should be fine as is! Ive run them with cracks no issues .