The Flywheel is connected to the ....
The Flywheel is connected to the ....
.. Nothing.
My flywheel bolts have decided to snap. Two snapped and the remaining 2 damaged their threads and undid themselves.
I imagine the massive 40something Hp the engine has is just too much!
Do we have a recommendation on repairing the bolt hole threads? I guess a slightly oversized thread for the bolt holes is the most permanent option.
Anyone had this before ? I did use a torque wrench when I did them up. They were the original bolts.
Thanks, Andrew.
My flywheel bolts have decided to snap. Two snapped and the remaining 2 damaged their threads and undid themselves.
I imagine the massive 40something Hp the engine has is just too much!
Do we have a recommendation on repairing the bolt hole threads? I guess a slightly oversized thread for the bolt holes is the most permanent option.
Anyone had this before ? I did use a torque wrench when I did them up. They were the original bolts.
Thanks, Andrew.
Andrew
1957 A35
1957 A35
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Re: The Flywheel is connected to the ....
You can get the damaged threads repaired with heli-coil inserts either yourself or at an engineering company
guess you take the crank out for repair to the engineering company or maybe another crank? It needs to be done properly as it is securing the flywheel after all.
John G
guess you take the crank out for repair to the engineering company or maybe another crank? It needs to be done properly as it is securing the flywheel after all.
John G
John (Tight Yorkshireman)
First referred to as the Tight Yorkshireman in editions of the Clubs Spotlight: Autumn 1996 Page 40 and Autumn 1997 Page 15
First referred to as the Tight Yorkshireman in editions of the Clubs Spotlight: Autumn 1996 Page 40 and Autumn 1997 Page 15
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Re: The Flywheel is connected to the ....
Did you use Loctite Andrew ?
It is possible to re-tap the damaged threads a little bigger, in situ, if you are careful and get them dead straight. Crankshaft is quite tough so beware snapping the tap !!
Use all new bolts. If you can,t get the ones with the reduced head send them to me and I will turn them down.
It is possible to re-tap the damaged threads a little bigger, in situ, if you are careful and get them dead straight. Crankshaft is quite tough so beware snapping the tap !!
Use all new bolts. If you can,t get the ones with the reduced head send them to me and I will turn them down.
- Neil Evans
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Re: The Flywheel is connected to the ....
I would scrap the flywheel as it's almost certainly worn the bolt holes...
Club Technical Information Officer
A30/A35 Club Member A191 (since 1972)
Father of the club's only love child
A30/A35 Club Member A191 (since 1972)
Father of the club's only love child
Re: The Flywheel is connected to the ....
Yes I had this happen on a 995cc race engine, caused by aggressive starts off the line. Standard bolts stretched hence losing clamp load, allowing the flywheel to loosen and then shear the bolts by impact.Hurtzberg wrote:Anyone had this before ? >>> They were the original bolts.
Suggest replacing standard bolts with high tensile socket capheads (ref photo). Chemically clean bolt and crank threads with degreasing spray and install using medium strength Loctite. Hardware torque can be increased to 50 lbf.ft if required. Caphead bolts can be refitted many times...
Redrilling 948 crank for 6 bolts and location dowel is the ultimate solution, but don't bother with just 40hp...
Re: The Flywheel is connected to the ....
Thanks all.
Dave, I was using new lock tabs not loctite. Do you recommend just loctite without the lock Tab?
BD, it could even be 45hp!
It will be a while before I can work on her again so I will probably just collect parts for now.
Dave, I was using new lock tabs not loctite. Do you recommend just loctite without the lock Tab?
BD, it could even be 45hp!
It will be a while before I can work on her again so I will probably just collect parts for now.
Andrew
1957 A35
1957 A35
Re: The Flywheel is connected to the ....
Throw lock tabs in the bin - they are hopeless. Use medium strength Loctite instead (not high strength because you may want to undo the bolts in future).Hurtzberg wrote:Thanks all.
Dave, I was using new lock tabs not loctite. Do you recommend just loctite without the lock Tab?
BD, it could even be 45hp!
Power isn't really the issue. Instantaneous torque peaks in the driveline are dominant, mostly due to inertia.
- gazza82
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Re: The Flywheel is connected to the ....
Well now we know what the funny noise was ....
"If you're driving on the edge ... you're leaving too much room!"
Club WebEditor.
Cars: "Project 757" '59 A35 2-door bought in 1971 & Subaru BRZ SE LUX Auto plus "family fleet": Alfa MiTo, Peugeot 206, (Ex '98 Alfa Romeo 156 2.0 TS)
Club WebEditor.
Cars: "Project 757" '59 A35 2-door bought in 1971 & Subaru BRZ SE LUX Auto plus "family fleet": Alfa MiTo, Peugeot 206, (Ex '98 Alfa Romeo 156 2.0 TS)
Re: The Flywheel is connected to the ....
Morning all,
Yes Gazza , it was good of the last remaining bolt to hold on for as long as it did!
A rare event happened on this thread, BD and DC both agreed on something !
Is the same recommendation for loctite instead of locktabs true for inside Engines too?
Is it ok to start the engine without the gearbox/flywheel attached? I'd need to use the cranking handle but it would be nice to check it was only the flywheel bolts causing the noise before a do the drilling and tapping.
Thanks again. Andrew
Yes Gazza , it was good of the last remaining bolt to hold on for as long as it did!
A rare event happened on this thread, BD and DC both agreed on something !
Is the same recommendation for loctite instead of locktabs true for inside Engines too?
Is it ok to start the engine without the gearbox/flywheel attached? I'd need to use the cranking handle but it would be nice to check it was only the flywheel bolts causing the noise before a do the drilling and tapping.
Thanks again. Andrew
Andrew
1957 A35
1957 A35
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Re: The Flywheel is connected to the ....
As BD says locktabs are a waste of space. Being soft metal they slowly compress enough to relax the tension on the bolt. I use ARP bolts on the big ends and not even Loctite but I would use it with regular bolts.
I know people have started various engines without flywheels but be very careful. It will rev like crazy and may be off balance as well. Flywheel is there for several reasons one of which is to damp vibration.
I know people have started various engines without flywheels but be very careful. It will rev like crazy and may be off balance as well. Flywheel is there for several reasons one of which is to damp vibration.
Re: The Flywheel is connected to the ....
Thanks Dave. Your knowledge is always very appreciated.
Andrew
1957 A35
1957 A35
Re: The Flywheel is connected to the ....
Appearances can be deceptive. Although always open to robust debate, these days I reckon Dave and I agree on over 95% of issues. Different approach can lead to the same conclusion...Hurtzberg wrote:A rare event happened on this thread, BD and DC both agreed on something !
...Hurtzberg wrote:Is the same recommendation for loctite instead of locktabs true for inside Engines too?
Don't do it With very low inertia, even small throttle changes can send engine speed soaring, causing damage...Hurtzberg wrote:Is it ok to start the engine without the flywheel attached?
So DC and BD agree again...
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Re: The Flywheel is connected to the ....
And we both like beer and red wine too
Re: The Flywheel is connected to the ....
And rugby union, good food and driving fast on race circuits...
Re: The Flywheel is connected to the ....
Speaking of which, Will we see either the s2000 or a Turbo mx5 at the Bird in the hand this year? Might even be some of that beer or red wine with your name on it.
Andrew
1957 A35
1957 A35