valves and guides.

[overherebc]

I'm looking for a reliable and careful mechanic who can replace the valves and guides on a 1964 alloy finned head from a twin cylinder bike.

I have all the parts but don't trust myself to do it. One mistake and it will take probably months to source a replacement head.

Pattaya area.

[thaiguzzi]

You mean recut the valve seats too after the guides have been replaced?

What's the c/head off?

[overherebc]

1 hour ago, thaiguzzi said:

You mean recut the valve seats too after the guides have been replaced?

What's the c/head off?

Brit 500.

I can use one of the old valves to do the seats initially and then fit and seat the new valves.

I'm just worried about damage to the head on removal of the guides.

I know the theory, heat the head to around 150 C  and using the drifter knock out the old guides. Reheat the head, put the new guides in the freezer the using the proper drift bar knock the new ones in.

Just never actually done it.

[Maybole]

I have done it a few times. Heating the head and drifting out the old guides, (quickly before the heat expands the guides) works well. If they do not move , try to drill them carefully but I do not recommend this method,  it is difficut to do without damaging the head. To remove valve seats, carefully drill two holes at opposite diameters and break them apart.

In both cases a hot head and frozen guides and seats will go together without force.

[Bung]

On old Brit bikes you need to be very careful with internal engine work and I doubt you will find anyone here really capable.  You really need to find someone who has experience with working on these bikes,  has Whitworth spanners and is careful. 

 

I would either send the head overseas to UK,  Australia,  nz etc or take it out with you when you go. 

 

You need to get it converted to unleaded as well which is special valves and guides if I recall. 

 

How's the piston/rings and bottom end? 

 

My brother just bought a fully restored thunderbird and it seized from having the wrong clearances. 

[thaiguzzi]

6 hours ago, Bung said:

On old Brit bikes you need to be very careful with internal engine work and I doubt you will find anyone here really capable.  You really need to find someone who has experience with working on these bikes,  has Whitworth spanners and is careful. 

 

I would either send the head overseas to UK,  Australia,  nz etc or take it out with you when you go. 

 

You need to get it converted to unleaded as well which is special valves and guides if I recall. 

 

How's the piston/rings and bottom end? 

 

My brother just bought a fully restored thunderbird and it seized from having the wrong clearances. 

Convert to unleaded is valve seats alone. Nothing to do with valves nor guides.

[thaiguzzi]

9 hours ago, overherebc said:

Brit 500.

I can use one of the old valves to do the seats initially and then fit and seat the new valves.

I'm just worried about damage to the head on removal of the guides.

I know the theory, heat the head to around 150 C  and using the drifter knock out the old guides. Reheat the head, put the new guides in the freezer the using the proper drift bar knock the new ones in.

Just never actually done it.

# Bit more specific please. Brand/manufacturer?

# If new guides are fitted, seats MUST be recut. Not just a quick old re-grind. So your 2nd sentence is irrelevant.

# Once the old guides are removed and mic'ed up, and the guide bores measured it is often common to recquire O/S guides. +0.001, +0.002" etc. May already have O/S guides fitted. Especially in an alloy head, iron not so often.

# I have all the tools and jigs and fixtures and measuring equipment here to do any recon on any Brit (and older HD) c/head. It was my work, life and hobby all my adult life. I also have a milling machine, lathe, shaper, and tool and cutter grinder here in my workshops.

# I owned a Triumph specialist engineering workshop (plus all other pushrod motors) back in the UK for 15 years, and the shop became well known world wide.

# So i'm not talking out of my arse.

# There is an excellent (and i mean damn GOOD) engine recon shop in Udon , one of the best in Thailand who can replace worn valve seats AND cut modern 3 angle valve seats with a state of the art Serdi valve seat machine. Cost of the machine (genuine - not a copy) a cool 2 million baht. He has two of them.....

# His one and only crank grinder is on 30k month wages plus bonus.

# He has a row of 7 (seven) Bridgeport turret milling machines working flat out doing head and seat work. Same number of lathes. 40 Staff.

# His rebore and hones are 1500 baht per hole. Not 500 baht as per local mom'n'pop corner shops. You get what you pay for, and you get a hole honed to the correct measured size as specified.

 Regards,

   TG.

[Maybole]

24 minutes ago, thaiguzzi said:

Convert to unleaded is valve seats alone. Nothing to do with valves nor guides.

I disagree, lead in petrol built up a self lubricating coating which which supplemented the lubrication from oil.

I recall valve failures in light aircraft engines when 100LL fuel was introduced in the 1980s. The engine manufacturers and overhaulers had to run the engines on leaded fuel for 10 hours to build this coating up. This was a temporary fix until new valve and guide metals were developed

[thaiguzzi]

7 hours ago, Maybole said:

I have done it a few times. Heating the head and drifting out the old guides, (quickly before the heat expands the guides) works well. If they do not move , try to drill them carefully but I do not recommend this method,  it is difficut to do without damaging the head. To remove valve seats, carefully drill two holes at opposite diameters and break them apart.

In both cases a hot head and frozen guides and seats will go together without force.

Only way to remove valve seats is on a milling machine. Anything else is a bodge.

[thaiguzzi]

2 minutes ago, Maybole said:

I disagree, lead in petrol built up a self lubricating coating coating which which supplemented the lubrication from oil.

I recall valve failures in light aircraft engines when 100LL fuel was introduced in the 1980s. The engine manufacturers and overhaulers had to run the engines on leaded fuel for 10 hours to build this coating up. This was a temporary fix until new valve and guide metals were developed

I'm quite familiar with light aircraft engines. Lycoming. Continental, the modern Rotax. If the guides are a quality bronze or even cast iron, and clearances are correct, there is no problem running unleaded. Yes, leaded was/is a better fuel for older designed engines, but the problem with unleaded when introduced was valve seats and valve seats alone. Oh, and spark plugs in light aircraft engines. To this day, nobody flying Cessnas, Grummans etc likes unleaded, and leaded aviation fuel (100-105 octane) is still widely available.

The valve seat/fuel  debate/problem only emerged generally with alloy heads with seat inserts. Many iron head motors never had a problem.

[thaiguzzi]

7 hours ago, Bung said:

On old Brit bikes you need to be very careful with internal engine work and I doubt you will find anyone here really capable.  You really need to find someone who has experience with working on these bikes,  has Whitworth spanners and is careful. 

 

I would either send the head overseas to UK,  Australia,  nz etc or take it out with you when you go. 

 

You need to get it converted to unleaded as well which is special valves and guides if I recall. 

 

How's the piston/rings and bottom end? 

 

My brother just bought a fully restored thunderbird and it seized from having the wrong clearances. 

Was'nt very well restored then was it?

All shiny on the outside impresses more gullable people than something unrestored with a nice bit of rust, history and patina, couple of oil leaks, BUT is mechanically sound, well built and runs like a champ.

A mate of mine just visited me on his '58 T'bird. All the way from Chiang Rai. And back. I'm the other side of Udon. Zero problems. You can read his (very well written and photographed) ride report in GT Rider. Oh. and his bike is C L E A N.

[Bung]

1 hour ago, thaiguzzi said:

# Bit more specific please. Brand/manufacturer?

# If new guides are fitted, seats MUST be recut. Not just a quick old re-grind. So your 2nd sentence is irrelevant.

# Once the old guides are removed and mic'ed up, and the guide bores measured it is often common to recquire O/S guides. +0.001, +0.002" etc. May already have O/S guides fitted. Especially in an alloy head, iron not so often.

# I have all the tools and jigs and fixtures and measuring equipment here to do any recon on any Brit (and older HD) c/head. It was my work, life and hobby all my adult life. I also have a milling machine, lathe, shaper, and tool and cutter grinder here in my workshops.

# I owned a Triumph specialist engineering workshop (plus all other pushrod motors) back in the UK for 15 years, and the shop became well known world wide.

# So i'm not talking out of my arse.

# There is an excellent (and i mean damn GOOD) engine recon shop in Udon , one of the best in Thailand who can replace worn valve seats AND cut modern 3 angle valve seats with a state of the art Serdi valve seat machine. Cost of the machine (genuine - not a copy) a cool 2 million baht. He has two of them.....

# His one and only crank grinder is on 30k month wages plus bonus.

# He has a row of 7 (seven) Bridgeport turret milling machines working flat out doing head and seat work. Same number of lathes. 40 Staff.

# His rebore and hones are 1500 baht per hole. Not 500 baht as per local mom'n'pop corner shops. You get what you pay for, and you get a hole honed to the correct measured size as specified.

 Regards,

   TG.

Well,  that's good to know. Not easy to find a good shop like that.  Wonder if there is something similar in Chiang Mai? 

[Bung]

1 hour ago, thaiguzzi said:

Was'nt very well restored then was it?

All shiny on the outside impresses more gullable people than something unrestored with a nice bit of rust, history and patina, couple of oil leaks, BUT is mechanically sound, well built and runs like a champ.

A mate of mine just visited me on his '58 T'bird. All the way from Chiang Rai. And back. I'm the other side of Udon. Zero problems. You can read his (very well written and photographed) ride report in GT Rider. Oh. and his bike is C L E A N.

It was a very well done ground up resto done by a mate who was a perfectionist but not an engine specialist in his shed.  It sat for 10 yesrs and ran fine but nipped up under hard acceleration. Nothing wrong with a restored bike but stuff happens. 

[thaiguzzi]

10 hours ago, Bung said:

Well,  that's good to know. Not easy to find a good shop like that.  Wonder if there is something similar in Chiang Mai? 

A lot of his straight 6 lorry and bus c/heads come from Chiang Mai. And BKK. It appears he has perfected some seat repair/alloy welding technique which is a common fault on certain straight 6 commercial diesel heads.

 He reckons he sends out never less than 4, sometimes 8 heads per day. I've seen them myself sitting there waiting to be sent out, all industrial cling filmed up. Look brand new, prices range from 35 to 50k per head depending what is done to them. His turnover is never less than 200k per day. Lovely fella too, former Vietnamese immigrant, illiterate when he arrived here as a boy, taught himself everything inc his spectacular alloy welding skills, which he has since passed on.

[thaiguzzi]

10 hours ago, Bung said:

It was a very well done ground up resto done by a mate who was a perfectionist but not an engine specialist in his shed.  It sat for 10 yesrs and ran fine but nipped up under hard acceleration. Nothing wrong with a restored bike but stuff happens. 

Coulda been a worn magneto. Or points gone out of synch. Unless electronic ignition was retro fitted.

Depends how a motor was stored for 10 years too, possible rust getting inside or seals going hard. Timing cover oil seal controlling oil pressure to the crank being nipped or gone hard, hence every bike I own (ed) always runs an OPG (oil pressure guage).

[canthai55]

11 hours ago, Bung said:

 It sat for 10 yesrs and ran fine but nipped up under hard acceleration.

A lot depends on how it was stored too. Nipped up - does this mean it seized ? Google search described some gymnastic manoeuver

[VocalNeal]

4 hours ago, canthai55 said:

Nipped up

This only happens to the big four?

[papa al]

15 hours ago, canthai55 said:

A lot depends on how it was stored too. Nipped up - does this mean it seized ? Google search described some gymnastic manoeuver

We say "tits up."

[thaiguzzi]

On ‎9‎/‎4‎/‎2017 at 10:32 AM, overherebc said:

Brit 500.

I can use one of the old valves to do the seats initially and then fit and seat the new valves.

I'm just worried about damage to the head on removal of the guides.

I know the theory, heat the head to around 150 C  and using the drifter knock out the old guides. Reheat the head, put the new guides in the freezer the using the proper drift bar knock the new ones in.

Just never actually done it.

Secretive OP still has not informed us what bike. 64 means its a unit T100 if a Triumph or a unit A7 if a BSA. Could be an Enfield, could be a Norton, could be a...? This will help due to different head designs, presumably 5/16" valve stems etc.

[overherebc]

4 minutes ago, thaiguzzi said:

Secretive OP still has not informed us what bike. 64 means its a unit T100 if a Triumph or a unit A7 if a BSA. Could be an Enfield, could be a Norton, could be a...? This will help due to different head designs, presumably 5/16" valve stems etc.

BSA 500 twin 60's. vibrates worse than a bad HD. The wonderful engine where both pistons rise and fall at the same time, one on power and the other on exhaust. 

A British exercise in how to build an engine that is next to impossible to balance, maybe nowadays you could spend a small fortune on dynamic balancing etc but would it be worth the money and trouble when all those vibes keep the circulation going. Probably designed so you had to stop every 30 minutes for a cig' to let your numb fingers come back to life.

[VocalNeal]

55 minutes ago, overherebc said:

This will help due to different head designs,

Let me see? Has four valve guide, four springs, etc. etc. sure they are all different. 

[thaiguzzi]

18 minutes ago, VocalNeal said:

Let me see? Has four valve guide, four springs, etc. etc. sure they are all different. 

How you mount the head on a bench jig.

Triumph heads have flat faces top and bottom.

Ditto BSA pre unit heads ie A7 and A10.

BSA unit heads ie A50 and A65 have the rockers held in the head, no separate rocker boxes with the rocker spindles in them.

Norton heads are a one piece casting, with rockers, spindles and valve gear all integral in one casting. Pain in the arse to hold and work on compared to the above. And compared to the above, a complete pain in the arse when the head gasket face needs a skim.

Anything else?

[thaiguzzi]

1 hour ago, overherebc said:

BSA 500 twin 60's. vibrates worse than a bad HD. The wonderful engine where both pistons rise and fall at the same time, one on power and the other on exhaust. 

A British exercise in how to build an engine that is next to impossible to balance, maybe nowadays you could spend a small fortune on dynamic balancing etc but would it be worth the money and trouble when all those vibes keep the circulation going. Probably designed so you had to stop every 30 minutes for a cig' to let your numb fingers come back to life.

# 500 Brit twin should not vibrate, certainly not like an HD. Something seriously amiss in there. Could be;

1. motor is in a different frame from what it was intended.

2. crank could be from another motor, ie flat tracker, circuit racer, scrambler or road bike, each having a different balance factor.

3. Conrods are not a matched pair and hence weigh differently.

4. Pistons, see 3 above.

5. Somebody could have lightened the crank - badly.

# I've had T140 750cc 76mm bore pistons, genuine Hepolite straight out of the box, sold as a pair weighing 1/4 oz different. That's 7 grams in new money. If fitted as was, that motor WOULD have vibrated.

# NEVER ASSUME ANYTHING. I've had Triumph pistons, genuine Hepolite measure up half a thou (0.0005") different, sold as a pair. If you believe what's written on the box you ASSUME the sizes are the same. If you get your rebore man to finish hone to size on that box without mic'ing up each piston, one is going to be a sloppier (or tighter) fit than the other. We would often have barrels and pistons go out marked A & B.

# There is nothing wrong with a Brit 500 parallel twin, should be pretty smooth unless you are just used to modern multi's. 100's of 1000's of the things were sold worldwide over nearly 40 years (37 to 73). The problems with reliability and excessive vibration came with the public's appetite for ever bigger cc's. 650,750,850... Yet even a 650 twin in a low state of tune is not unduly vibratory and should be relatively smooth.

# A Brit parallel twin 360 degree crank is relatively straight fwd to balance anywhere between 50 to 85% balance factor, either statically or dynamically. As said above, different from std rods and pistons will affect the original factory balance factor.

# I was going to offer my services to remove your old guides, and at least inspect your new components, and fit them if I was satisfied with their quality, but, no disrespect intended, by the sounds of things, the motor has more issues than just shagged guides and needs further stripping down and inspection.

 Regards,

   TG.

[ktm jeff]

TG , everytime i read these informed write-ups and replies from yourself , i have to read them more than once so the technical information slowly sinks in. Ive worked on more modern cars , bikes , boats , and strokers , ( even my neighbours plane ! ) , but not old / Brit / HD stuff. You certainly know your craft. Do you offer workshop tours .  He He.

[overherebc]

6 hours ago, thaiguzzi said:

# 500 Brit twin should not vibrate, certainly not like an HD. Something seriously amiss in there. Could be;

1. motor is in a different frame from what it was intended.

2. crank could be from another motor, ie flat tracker, circuit racer, scrambler or road bike, each having a different balance factor.

3. Conrods are not a matched pair and hence weigh differently.

4. Pistons, see 3 above.

5. Somebody could have lightened the crank - badly.

# I've had T140 750cc 76mm bore pistons, genuine Hepolite straight out of the box, sold as a pair weighing 1/4 oz different. That's 7 grams in new money. If fitted as was, that motor WOULD have vibrated.

# NEVER ASSUME ANYTHING. I've had Triumph pistons, genuine Hepolite measure up half a thou (0.0005") different, sold as a pair. If you believe what's written on the box you ASSUME the sizes are the same. If you get your rebore man to finish hone to size on that box without mic'ing up each piston, one is going to be a sloppier (or tighter) fit than the other. We would often have barrels and pistons go out marked A & B.

# There is nothing wrong with a Brit 500 parallel twin, should be pretty smooth unless you are just used to modern multi's. 100's of 1000's of the things were sold worldwide over nearly 40 years (37 to 73). The problems with reliability and excessive vibration came with the public's appetite for ever bigger cc's. 650,750,850... Yet even a 650 twin in a low state of tune is not unduly vibratory and should be relatively smooth.

# A Brit parallel twin 360 degree crank is relatively straight fwd to balance anywhere between 50 to 85% balance factor, either statically or dynamically. As said above, different from std rods and pistons will affect the original factory balance factor.

# I was going to offer my services to remove your old guides, and at least inspect your new components, and fit them if I was satisfied with their quality, but, no disrespect intended, by the sounds of things, the motor has more issues than just shagged guides and needs further stripping down and inspection.

 Regards,

   TG.

Numbers frame and engine both relate to original manufacture, checked with BSA UK.

No change of frame or anything from original.

My experience of Brit bikes goes back to the 60's and vibrations or engine buzz was a common thing. They were fairly mass produced for cheap transport in the 50's/60's after the war and using old tooling used for war mass production.

Had lots, Sunbeam 500 in line twin, C11 Bsa, C15 G ( the sports version ?? ) AJS 500, Tiger Cub 200 etc. They all had vibes.

The real changs came when Honda brought out the CB 750, that was smooth, had a CB 650 first and that was good at the time but the CB750 changed everything. 

Game changer was my CX650 Turbo in 81. Scary the first time you ride it. Even today people don't believe how quick it was off the line in 1981. I won't quote the fiqures, google it.

??

[VocalNeal]

12 hours ago, overherebc said:

Sunbeam 500 in line twin,

My best friend had one of these. Couldn't find/afford a real back tire so being way ahead of the Harley guys he put a car tire on the back. One day going home for lunch ran into the side of a Morris 1000 van (practical joke gone wrong) . Bent the van behind the door and pushed the fan up against the radiator. The Sunbeam has a bent mudguard!

[thaiguzzi]

5 minutes ago, VocalNeal said:

My best friend had one of these. Couldn't find/afford a real back tire so being way ahead of the Harley guys he put a car tire on the back. One day going home for lunch ran into the side of a Morris 1000 van (practical joke gone wrong) . Bent the van behind the door and pushed the fan up against the radiator. The Sunbeam has a bent mudguard!

An S8. A lot of them came with 16" rims and Harley type balloon tyres, unusual for a Brit bike.

Nice, different, good looking bikes too.

[thaiguzzi]

14 hours ago, ktm jeff said:

TG , everytime i read these informed write-ups and replies from yourself , i have to read them more than once so the technical information slowly sinks in. Ive worked on more modern cars , bikes , boats , and strokers , ( even my neighbours plane ! ) , but not old / Brit / HD stuff. You certainly know your craft. Do you offer workshop tours .  He He.

Thank you kind sir! It's good to feel the love sometimes...

W/shop - pop round anytime.

 

[VocalNeal]

It was green so may have been the earlier one. There were a few old car in the yard so the tire may have come from one of those as 16" would not have been a common size  back then.

[thaiguzzi]

The other container;