110mph and BANG: TERRIFYING to see what could have potentially happened to me!

Well guys I’m a little down today after our weekend away at Castle Combe. It started well but the horror struck down the straight, this is what we found

[@fredflintstone8048]

"It wasn't an engine issue" - It was a engineering issue. The spacer should be pinned and not use bolts to take the torque.. There's always some spacing in a bolt hole due to lack of precision of bolts in size in general. The torquing back and forth will stretch the bolt in time and if it doesn't loosen up, it will snap. I would say at least two steel pins opposite each other in between the bolts if not 4. Lee's solution sounds pretty good as well.

[@readrepairs]

Agree, dowel pins x 4

[@gourdarchibald6588]

When you are Engineering a fix for your prop shaft make sure the solution removes shear load from the bolts / screws. You can build the whole rig with quality assured 10.8 bolts and your existing setup would still fail because of the shear load, you need positive registers so the bolts only see their designed purpose of tension. As others have said physically constrain the shaft in the event of failure, I think you've already worked out what could have happened. All the best, I hope you stay safe and get everything fixed soon. ✌👍

[@Snark900]

Exactly what I thought. Machine grooves in the mating parts, only needs to be a couple of millimetres deep and have a positive transmission point.

[@Snark900]

Exactly what I thought. Machine grooves in the mating parts, only needs to be a couple of millimetres deep and have a positive transmission point.

[@stephennelson624]

It looks like there’s a crack in the casting where the water pump housing attaches to the block mate

[@Ben-Dixey]

You noticed a problem but decided to carry on regardless. For a mechanic that issue would be easy to diagnose, perhaps take it to a garage next time you hear something strange and can't work out what it is.

[@JeffSchofield-y8q]

Give us a shout Northwest PROPSHAFTS !

[@laser-sj]

BIG obvious crack in base of the water pipe as it goes into block. 🤪

[@minigpracing3068]

Can you change up the output adapters and fit a U joint or CV joint in there? A little bit of flex might be a good thing. Can you also put some kind of drive shaft protection around that end to help prevent it from flapping around so much if it breaks again?

[@mikehipperson]

110mph in first gear! What did you expect? 🤣🤣🤣 You should fit a 'saver' tube around both ends of the trans shaft in case it happens again (which it will!) just like they do in drag racing.

[@eyeswideshut7732]

i agree, tube it up, if it come off again it can only rattle an inch...

[@Paxmax]

..or atleast a safety loop at the end to limit the buggery it can do.

[@legacyofpop]

Lee.... I was binge watching your videos the other day, and in one of them you explained why you don't do diesels.... now I can't find it, but I would really like to watch that one again. Do you remember which one it was... ? Also... in my limited drag racing days, I always fitted a system to restrain a liberated propshaft... just a ring assembly to limit the shaft from flying about. Saved me a small fortune, and protected my legs and hardware from a severe pounding. Thanks so much for great videos... very binge watch worthy.

[@Marka1230]

I thought I could see a crack in the water pump housing

[@stephenclark2058]

And make sure you get the prop shaft balanced properly 🤔🤔

[@chillierdavro]

100% need a prop cage/catcher have seen someone get there leg smashed in with a lose prop not good! Put the catcher in it and test it holds when rolling.

[@v4skunk739]

That sounds painful.

[@stephenmarshall9574]

It would make sense to bolt the spacer to the flange with the bolts recessed into the spacer then drill and tap the spacer to bolt on the prop shaft.

[@glennstocker487]

Condolences gentlemen, consider yourself fortunate you still have two "Pins". Given your fast becoming a cosworth renowned shop perhaps time to consider a worthy kit car chassis to mount your show piece - say a very trick, very pretty, cossi motor to demonstrate your shops skill set at track days. Just a thought? Cheers From DownUnder.

[@craiglaing2417]

Maybe the spacer was slightly off balance? Might need a custom prop and a prop retainer 👍

[@JeffPower-dv3zl]

Definitely 😊

[@paulfackrell1502]

Hi Lee on the kit car you got to alter the ratio on the pedal by moving it closer to the pivot point i had the same on my race car, and with the propshaft the adaptor counter bore the hole already their and put four more tapped hole to take flang of propshaft and lock tight all the bolt this should work, i have been racing for 46 years

[@jeffboyer8214]

Safety wire is a great idea. Also use a paint pen as tighten bolts and you can see if they move & they will move . Glad you are safe.

[@john-paulthompson4932]

As you say teething issues. Getting a correctly sized prop shaft is a very good idea. I remember seeing that some race cars have a prop shaft catcher to stop it from either dropping to the road and potentially lifting into the air or worse entering the cabin.

[@davidcoyle7125]

Goodness that could have been life changing and not in a good way, easy to be an armchair critic but at the end of the day disappointing the drive failed but great the blackbird engine goes well and am sure after its repaired/upgraded the kit car will be better than even and even more smiles per mile, enjoy.

[@davidrogerbinnyi2573]

2 Precision dowels fitted to the gearbox flange / adaptor would take the torque of the drive leaving the bolts to clamp the prop shaft on . Had a similar problem when someone changed a flywheel on a Bedford diesel tipper and the dowel holes didn't line up , so they left them out . First load out of the site sheared all of the bolts ...Really enjoy your videos and the banter between you both ..

[@christiangill3759]

We use cardan shafts like that on machinery, normally on a shaft that size you’d have 6 or 8 bolts, don’t understand why there’s only 4. Also the bolts would be wired to make sure they don’t come loose. Spacers are sometimes used with no issues this is because the bolts clamp all faces together, the faces transmit the torque, the bolts don’t take a shear load they are in tension. If the bolts haven’t been torqued properly allows the bolts to take a shear load, which is wrong..

[@JimHurst-o1x]

Lot of good advice and ideas here, question is... anybody listening???

[@paullangford7078]

If there's any movement on the engine or diff then they will pull apart straining the bolts. You might need a sliding joint on the prop

[@stevesweet2567]

Is there nothing in the reg's to specify a safety cage around the drive shafts?

[@paulnolan1352]

Cheers Lee, the trials and tribulations of Motor racing. Sort the prop properly (haha) and crack on.

[@richardpoulter2146]

Strong lock tight everything and safety wires if it’s not a proven system that’s if you want to live

[@billweston6579]

Get the prop shaft lengthened. That bent shifter shaft is going to be fun to get out. Put a smaller bore, longer stroke, master cylinder on the clutch and/or bigger bore slave cylinder. Will extend the take up area. Bike clutches don’t have as much cushioning in the clutch. You don’t have a lot of movement in the clutch lever

[@henktulp4400]

Hihihi… Reminds me of a mishap a few decades ago….. The better half of a friend of me complained about the car (an aged Opel Record) making some noise…… He decided to ignore her wining for some time… A couple of days later he had to collect the car with a trailer….. the propshaft was sticking up through the car’s floor!!

[@alanblackford2962]

I think the mouse slackened off the propshaft bolts before he died ?

[@dannykimble7671]

Machines I used to work on always had a safety hoop around the props in case of failures ( which happened quite a lot) saved a lot of damage & obviously if the front fails & drops to the ground disaster.

[@philiptrueman8894]

Get rid of that spacer for the prop shaft. It was always a failure waiting to happen. That's why the gearbox was making a noise because there is no room for movement in the propshaft. Don't propshafts have some kind of sliding splines like front wheel drive vehicles.

[@killbit]

Great to hear about your weekend adventure.

[@buckrogers2828]

Reason it was quiet and not in midd range is revved it's under load and slow it's loaded by car but in mid it's floating so anything that can be loose will be!

[@patstevens2959]

You'll get it fixed and have a go again, could've been worse!! keep your spirits up!!!!!!! You saw the potential.All good!!!!!!!! learning experience!!!!!!

[@josephlawless6013]

You should consider adding a set of bolts to the spacer so the spacer is bolted to the adapter, then the prop shaft bolts to the adapter. That way you can use shouldered zero clearance on both to carry the torque. Lastly match drill roll pins through the assembly.

[@ANDYblacks13]

Not good to see but why is the new engine so filthy like it wasn't cleaned before fitting? any oil leaks you won't be able to see were its leaking from at the very least,and just lengthen the prop that spacer is a bad idea, don't waste time trying to make it work, eliminate the weak links keep it stupid simple imo

[@JeffPower-dv3zl]

Exactly 😊

[@JeffPower-dv3zl]

Hi Lee you need to get somebody to do your administration work take care onwards and upwards 😊

[@richardhartley7094]

Those prop bolts couldn’t of been tight and with the sharp clutch too didn’t help matters so you got the jackpot I would say oh dear👍

[@petercourtney4749]

Long studs on cozzs but not enough thread on a prop school boy error

[@pnishi]

Why don’t you use safety wire to tie the bolts into position and not loosen?

[@colinscutt5104]

they sheared,not losened

[@Fjdnsksk]

Hey bud ive been watching you for a long long time but never really commented, keep up the great content guys and dont listen to these keyboard mechanics that hate on anything they can, they really hate themselves. Much love from Beltec performance.

[@AndrewNeilBaird]

Mole grips on a fuel pipe , so thats the next thing to split , derp award of the week.

[@philipslater9450]

Is it possible to increase the number of bolts on the prop? Less chance of shearing the bolts.

[@williambramer8217]

I can’t believe you did not machine yourself some hi-tensile steel shoulder bolts or studs to take out the slop. The prop is a balanced part and the spacer needs to be firmly held in place and the balance maintained. Probably the cause of the rattle with the prop shaft transferring the rattle to the rear.

[@roy2689]

just a thought here, perhaps think of drilling the holes (if there's sufficient metal to do so) from what look to be 8mm to 10mm bolts and use higher tensile steel bolts, if there isn't enough area for the larger head size of the bolt to sit in the flange you could use cap head bolts instead, and of course lengthening the propshaft to the correct length...

[@ralfie8801]

If you need to use that spacer, then it should have 4 counterbored holes to bolt the spacer to the adapter on the engine with short enough bolts that the bolt heads are below the shaft mating surface on the spacer and then 4 more holes threaded into the spacer for the shaft to bolt into the spacer. That way you’ve got everything bolted down tight. Obviously lengthening the drive shaft is the best option, but the spacer modification could be done in your own shop with nothing invested but some time and the cost of 8 new bolts.

[@chrish4469]

Fitting a tail shaft loop, Would be wise

[@danpoxon2425]

Can’t you weld the spacer to the adapter then machine it so it’s runs true then use titanium bolts instead of 4 bolts run 8 ?

[@ctmperformanceengineering]

Keep up the good work lee…must say them cylinder heads look wicked 😏

[@mikedjames]

Maybe use two fish plates on the spacer/ coupler, with lock washers on top, and use shoulder bolts. So when it slides around under torque, the fish plates slide but the bolts are locked to the fish plate. The fish plate and the bolts become springy hoops tying the prop shaft to the gearbox output flange.

[@stevenlangton5607]

Next time lockwire the bolts in as with most racing applications ! as in the old days lol !

[@paulcooper3934]

Classic Subaru WRX clutch set up may work ?

[@malcolmadams1051]

Perhaps a good read-up on driveshaft forces and stresses?

[@andythorne1261]

that needs to have a spline drive and not reliant on the bolts, bolts are only to hold it together, or a shaped spacer to take the power

[@keithfletcher6123]

As soon as you quickly described that drone / vibe I thought … prop shaft … lucky escape I think could have been carnage with a capital K 👍

[@iancrashley9071]

Unlucky…defo need a prop shaft catcher, checking that the prop is suited now for the new engine, length and rotational speed are key aspects, any good propshaft manufacturer will be able to confirm them and wire locking. Easy fix so get another day booked or you’ll put this to one side!

[@MegaReddevil71]

Could the prop flange be altered so no adapter required it bolts straight up

[@woollamiainternationalfilm5285]

Install spacer aft next time? With the load pins as suggested.

[@DavidReid-fn5rs]

All the way from Scotland and didn’t see the kit car go!☹️

[@TheBlibo]

Hi hope those screws were at least a 10.9 grade, it is worth using shoulder bolts rather than set screws

[@JohnK8]

Maybe safety wire the bolts.

[@AdiFury]

Prop bolts and adapter need to be regular check items. Never had it myself but know of liads of other BECars doing it. Lucky thats all it did. Worst case it comes through into the pedal box and takes out your ankles. When you get the beware prop in, look at fitting prop-catcher hoops. As long as they're close they'll stop the prop flailing if it happens again.

[@AdiFury]

Also 8.8 bolts arent good enough. 12.9 on mine. Difficult to get nuts on so i loctite and paint mark the bolts on mine as well so it's easy to see if they've moved.

[@Andy-pe6tc]

Chaps, if the prop bolts have sheared adding nuts to the new bolts may not make a difference. The issue seems to be the amount of torque rather than the bolts coming loose. Notwithstanding the lengthening of the prop (good idea), I think you will need to calculate the thickness of the bolts to ensure they can withstand the torque of the new engine. Sounds like you may need either thicker bolts, bolts of a higher shear strength, additional bolts or a combination of all three. Hope you get it sorted soon. 👍

[@DickMorbey]

Was the shaft fitted using setscrews or shouldered bolts? I know of a similar failure on a 1930s racing MG Magnette at Goodwood only a few years ago where the rear prop shaft flange was secured with setscrews, which then chafed and failed!

[@davidpirtle1076]

You got a real pass on what could have been at least a severe injury and possibly life ending. Get a safety loop at least on the engine end of the propeller shaft. That might have saved the equipment from some of the carnage. When you reassemble it, consider a light coat of loctite 420 or whatever the equivalent is in Great Britain on the drive flanges. It was at one time the highest strength and temperature stuff they made. I highly doubt the engine would make enough torque to shear the bond. The driving force will be borne by the bonding agent and not totally dependent on bolt torque/clamping force. Be prepared to apply heat to disassemble it. Hopefully, it's not a harmonic torsional vibration issue. If that's the case, you will need a damping ring or possibly an aluminium or composite propeller shaft. Without having seen the setup, if you are not running constant velocity joints instead of cross universals, that would help or completely eliminate all the issues. Good luck and next time stick a gopro to your helmet!

[@500bht]

Alignment issue vibration from the universal joint has weekend the bolts to the point of snapping I did notice your engine is not square to the car

[@bumcy2010]

If you are going to use that spacer you perhaps should dowel it at both ends, be safer to extend the drveshaft! Cheers

[@70sAirForceBrat]

It's funny. The difference between the UK and the United States on certain words. The UK says prop. United States says drive shaft, The UK says bonnet United States says Hood. That that prop adapter AKA drive line should been a eight-hole instead of a four. It should have been bolted to the engine first. Then the drive shaft bolted to the adapter. Keeping the bolts short kind of like a wheel spacer would add strength and not have a super long bolts that would vibrate loose and snap.

[@davidclarke3643]

is it a 1 piece prop? maybe you should build it as a 2 piece with a bearing in the middle.

[@scottwood1388]

When things go astray it can be a bit aggravating but as time goes by they make for better stories. Do not get caught in a trap where you measure the good in ounces and the bad in pounds.

[@TheOriginalDaveJ]

Told you to avoid the Blackbird engine. They were built for cruising, not thrashing.

[@AndrewNeilBaird]

Also , its not a wheel spacer the boy racers put on their honda civics, its a very high stressed coupling . You should look at a CV joint instead of a hardy spicer , to even out the torque transfers. Which could be the source of the vibration harmonic you describe. Either way , like the other comments a safety loop is needed , all the other components vunerable to this type of failure need risk mitigation . What if the apprentice had been severely burned if this failure had gone wrong with him in the car , ??? Get a professional approach to building this thing or sell it on and admit its beyond your "ken"

[@TheMadManPlace]

Thick spacers with long bolts are almost never a good idea. You have probably seen cars with thick wheel pacers - anything from 25mm to as high as 50mm - to get the track wider. People do not realize just how much strain some bolts or studs have to endure and just how quickly things can go south in a big way. I was service crew on an ex factory Fiat Abarth 131 and we had the factory motor try to murder the alternator - the conrod came out the side and beat the poor alternator about the head - "electrical problems" you know. Anyway, we fitted a 3.5 Rover V8 to it and it went like the clappers. The only 15 inch rims we could get had a major difference in offset, so much so that the tire was hard against the shock and the wheel nuts were not even home yet. So I got 2 round chunks of ally and machined up 2 spacers almost 50mm thick. BUT I machined them in the way that the spacers were first bolted to the hubs with the nuts just below the surface of the outer face of the spacer and then separate holes were drilled and tapped into the spacer outer face and some VERY high tensile studs inserted (with copious amounts of red Loctite) the full thickness of the spacer to keep the rim/tire on. They worked well but took a bit of time to machine. Didn't have such nice things like CNC machines back then now did we. Didn't even have DRO's (Digital Read Out) either - everything was done with the vernier scales on the machine handles. But the jobs got done now didn't they. For interests sake, the Rover V8 we put in was just short of 20 pounds lighter than the 2 liter Fiat motor we took out.

[@davesadler7103]

Looks like you got a flat floor so i'm guessing a one piece prop shaft with no centre support,hideously long,bike engines are best left in bikes!

[@melvilib]

You may need to replace the selector shaft bush.

[@JimHurst-o1x]

Unbelievable! Have been involved with high performance cars and bikes for years. If you know there maybe a weakness, you sort it! Before! Going out on track! Lock wiring, it's called, apart from getting your original engineering right! If that's advertising your business?? And don't get the basics right in motorsport! I wouldn't bring an engine to you. I'm not a "hater" but, if your in the business, then everything should be triple checked, before you post your experiences on KZbin.

[@jacketrussell]

That'll be 'interesting' removing the gear change shaft.

[@wriggiepark-jn5vo]

Four bolts holding all that energy really,as you can see that did not work, must do better!!!

[@Bristolcentaurus]

another vote for drive shaft catch straps - pole vaulting on the drive shaft is a film stunt trick - should not be used on race tracks and is outright prohibited on drag tracks - drive shaft restraints are mandatory on the drag cars i am familiar with

[@PatrickSwayzeOnDbol]

have you seen what Lee Lockwood did to his LS swapped E30 manifold? lol edit: let us know when you are down Perranporth, I only live Newquay so could pop over.

[@garrypritchard1658]

Its vibrating and making a bad noise so ill go out and flog it and find out what it is boy racers with no idea about car prep (and call themselves top engine builders)😢😢😢😢

[@bish1121]

Drill out the flange & add more bolts & wire them would be my advice.

[@lesklower7281]

You on top of your failure on your motorcycle engined kit car lengthen the prop shaft and you obviously engine builders and al.those lovely shiny engine parts

[@paulhoogeveen7353]

Derek (VGG) appoved solutions.....

[@brianmorris6965]

Hope you kept the fireblade engine

[@andrewphillips6053]

Well looking on the bright side, when all the niggles have been rectified, what the car going to be like? Go kit car go!

[@kiwibobnz9812]

Get rid of the spacer replace the shaft with one the right length don’t put it back in

[@Tricky-11]

I swear I could see a crack in the back of the water pump?

[@andy530i]

It also looks as though the long bolt at the bottom is slightly bent over to the left @ 7:40.

[@STANLIZ4]

Just pleased you werent hurt could have been very nasty, thank God you werent!!

[@graemegill4773]

Boys nothing wong with having a spacers, BUT NEVER USE A BOLT THOUGH A SPACERS WITH NO SHOULDER ALL THE WAY THOUGH and make sure the bolt grade is right. Know this from experience. Better luck next outing😊

[@philipthoreau3590]

Alignment?

[@jennycarr6576]

What's the 2nd channel called? Tia

[@Jester-Riddle]

I seem to recall it was mentioned as Barum BTS ... (BTS meaning behind the scenes). Hope that helps ....

[@terencehawkes3933]

Oh bad luck!!!

[@fatwalletboy2]

Yeah isaacs right that prop could have punched into the cockpit or possibly dropped to the floor and flipped the car......

[@Ibh111142]

All part of the game guys, nothing to get depressed over.

[@koerttijdens1234]

Kitkat cars are the best.

[@PatrickFrawley-h7f]

I assume there's a bearing where the drive shaft comes out, you might have a job getting the bent drive shaft out ?

[@pauloneill8912]

absolute fud

[@geoffoliver6788]

Drill & tap 8 holes, then tighten up on both sides of the spacer using high tensile bolts.

[@peterwoodhead2569]

Not the correct solution

[@martinstone3656]

Those famous last words "Do it properly" you would of thought getting it right from the off is what its all about, still your in one piece which is what counts. From an engineering point maybe look at the inertia created when the prop is rotating, it creates a torque which results in shearing stress on the connection just like you get on propellers on boats, that knock up spacer you had was a wrong un for sure so your idea of making the perfect prop is where to go next, I would also test it on the road for some miles before you start acting like Max Verstrappen, just my thoughts

[@paulhughes5543]

i had a metro many moons ago with 2lt mg vvc init was like a rocket ,,, i just kept snapping front socks was heavy motor