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virgil
Original Poster
1,521 posts
94 months
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So finally got the Engine out of the car...dropped it down and out from underneath.
Block, crank, pistons etc.
Now if anypne cares remembering back I was striping the engine as I had quite a bad knocking sound just before I took it off the road. Thoughts so far have been big ends, journal bearings. slipped liner and when I spoke to V8Developments recently re cam shafts, Shaun suggsted checking the pistons for stuck gudgeon pins cuasing piston slap.
Well, I'm fearing worse than all that as the crank nose is very loose and wobbly. can move it back and forth with a few degrees of twist...like it's a very very loose corse thread.
Engine's not on the stand yet and am pff to the States tomorrow first thing for a week of work, so no full diagnosis for a week...but any guesses as to what it might be...
a broken crank??? can't think of anything else it might be :-(
what makes me wonder though is the nose is still connected (somehow) to the rest of the crank...all the pistons turn fine when turningthe front pully...weird!
Thought?
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SSPPGG
1,155 posts
72 months
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the crank can snap, but the snap can be "staggered" across the crank at an angle, such that it will still turn the pistons, as the crank pieces are held in sity by the bearings.
doesnt sound good though, good luck
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rev-erend
17,924 posts
154 months
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Could be just the front pulley.
Sometimes the bolt loosens and is lost .. and the pulley they wears the crank.
It that is the case it could be worth buying a John Eales Pulley as that is a very tight fit indeed.
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virgil
Original Poster
1,521 posts
94 months
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Sadly not the pully...pully is off the engine and the crank itself was wobbling. nice thought though!
Can't wait to get back home to pull it apart to take a look. dreading what I'll find though...
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SSPPGG
1,155 posts
72 months
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bad luck chap, hope its not too bad
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rev-erend
17,924 posts
154 months
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virgil
Original Poster
1,521 posts
94 months
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Well, just got the sump off and indeed the crank has snapped. arse... It's broken just before the first journal. explains the horrid noise when I took it off the road. but fairly impressed it managed to still start and drive.
Bearings are all pretty much half silver and half copper, but ironically the rest of the crank and bearing surfaces are all in good nick.
Block's taken a small rubbing where the crank nose went floppy but it's not a thrust face, so won't matter when it goes back together.
some wear on the followers (some dished bottoms) so they're in the bin already as will the cam be once it's out.
All needs a bloody good clean up as oil everywhere...and i'll get the lot balanced properly once going back together.
Now just got to decide if it's 500 crank going back in or an upgrade. Just buying a new house, so spare cash at a minimum now...damn!!
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SSPPGG
1,155 posts
72 months
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have a good check of liners, and of course valve and pistons...it doesnt take much to push a piston sideways and crack a liner, and it is not always very obvious
still.....upgrade time!
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TVR Beaver
2,142 posts
50 months
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Real Steal do a stroker kit that includes a 5 Ltr crank (new rods / pistons etc)... I wonder if these cranks are stronger than the 5 ltr TVR ones?.... or will you go std TVR crank??
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virgil
Original Poster
1,521 posts
94 months
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SSPPGG said: have a good check of liners, and of course valve and pistons...it doesnt take much to push a piston sideways and crack a liner, and it is not always very obvious
still.....upgrade time! crank is still in..away again for a couple of days, so just had time to get the engine on the stand and drop the sump and check the mains. will take a look... TVR Beaver said: Real Steal do a stroker kit that includes a 5 Ltr crank (new rods / pistons etc)... I wonder if these cranks are stronger than the 5 ltr TVR ones?.... or will you go std TVR crank?? not sure yet - will give sean a call at v8d and see what the options are from them...if the difference between a straight swap and an upgrade is negligible then it makes sense to upgrade. just didn't want this cost right now.. here's the end on shot with crank nose missing...  here's the close up of the break.  here's the crank end...  and here's the cam - showing signed of wear and some of the followers were dished. doesn't look too bad though if it's done the whole 50 odd thousand miles the car has done... 
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EGB
979 posts
27 months
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Very sorry to hear of this happening. Any idea what may have brought it about. High revs, low revs, pre ignition etc ? I have heard of some diesel engine cranks breaking on tick over!
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TVR Beaver
2,142 posts
50 months
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V8 Turner also do the bit's... upgraded cranks etc so talk to them as well.
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Interesting pic... why on earth would the crank snap at that point??. Very strange... you would think if it's going to go, it would be towards the back where its seeing all pistons working on it out to the gearbox... What weights on this bearing.. the front piston and the cam chain??
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rev-erend
17,924 posts
154 months
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Also the front pulley, maybe the balance weights were removed or some other change ?
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EGB
979 posts
27 months
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I read somewhere that the TVR factory were concerned about the quality of the cranks supplied to them for some of their early engines. True or not, they used to throw them onto the ground to test if they broke !! Ummmmm TVR quality testing.
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SILICONEKID340HP
8,567 posts
101 months
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I have the V8D 5l engine ,the crank is from a 4.6 then over bored to 96mm with top hat liners to create 5l.
Its just another way to do it but no chance of a broken crank and it revs better.
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v8 racing
1,977 posts
121 months
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TVR Beaver said: V8 Turner also do the bit's... upgraded cranks etc so talk to them as well.
.
Interesting pic... why on earth would the crank snap at that point??. Very strange... you would think if it's going to go, it would be towards the back where its seeing all pistons working on it out to the gearbox... What weights on this bearing.. the front piston and the cam chain?? You also have the mass of the flywheel turning the back of the crank, whilst at the front you have 16 valve springs all at approx 300ibs of pressure!, to be fair most of the cranks i have seen snap, the majority are at the front, dont panic yours is the later large journal which is a lot stronger, but also the overlap on the 2.3"main cranks is massive and not much metal to support them, where they snap there is only about 2mm of cast metal
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TVR Beaver
2,142 posts
50 months
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v8 racing said: TVR Beaver said: V8 Turner also do the bit's... upgraded cranks etc so talk to them as well.
.
Interesting pic... why on earth would the crank snap at that point??. Very strange... you would think if it's going to go, it would be towards the back where its seeing all pistons working on it out to the gearbox... What weights on this bearing.. the front piston and the cam chain?? You also have the mass of the flywheel turning the back of the crank, whilst at the front you have 16 valve springs all at approx 300ibs of pressure!, to be fair most of the cranks i have seen snap, the majority are at the front, dont panic yours is the later large journal which is a lot stronger, but also the overlap on the 2.3"main cranks is massive and not much metal to support them, where they snap there is only about 2mm of cast metal Hi Rob... in comparison with what goes out the flywheel end, you'd think the valves would make little differance.. thats amazing... but if you say they mostly go at the front??... just appears strange at first sight... BTW,,, I need a chat... my Chatter at 1300 RPM on over-run when warm is driving me mad! LOL.. 
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Precat
153 posts
95 months
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Sorry to see the state of your engine.
When looking at your pictures, I notice the main caps are of the early type with small registers.
These do not give much support to the crank when compared to the cross bolt type fitted to the later 500 engines, though the cross bolts were not generally fitted. The later main caps are a better fit in the block and give more support to the rotating assembly.
If you can have a look at the later 4.6 block and the main caps you might find it useful.
From a cost affective point of view, a 4.6 short motor, fitted with 4.0ltr pistons is an option.
I know it's not a 5 ltr
Hope these thoughts help. Precat
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jeboa
425 posts
131 months
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I have the same engine. The journals are the smaller (2.3") type, even though the block is the later type (HRC2411) which has the castings for x-bolting - it seems that TVR power never implemented that until later. Not sure why, maybe the availability of the blocks, or maybe they had a lot of small journal cranks left to use up?
I'm still considering what to do with my 5.0ltr engine at present. It's out of the car, and I'm putting in a V8D 4.6 for now. I may re-build the 5ltr over the winter - will give me something to do in the garage!!
My engine sufffered from a disintegrated distributor drive gear. The crank is in perfect condition, but it looks like I may need to spend close to £1k-1.5k to rebuild.
Alternative is to sell as parts, any ideas what the following would be worth:
Block (not x-bolted) £
Small journal 5ltr crank £
Flywheel (TvR 500 lightweight) £
Pistons (+TVR conrods) £
Heads (Big Valve, ported, etc.) £
The flwheel would need to be neutral balanced (unless sold as a set with the crank, and the pulley)
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virgil
Original Poster
1,521 posts
94 months
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I've spent another 15 mins looking at the engine (selling the house to buy another leaves little time!) and the fly wheel and front balancer look fine...nothing fallen off, but guess it might have been out of balance and just got tired.
It's the 2.3" big end jobbie and ironically, the big ends are in perfect nick and the mains are fine even though the bearing was a little worn (I guess a flapping around cronk hose didn't do it any favours!).
I've got aome options from V8D for bottom ends...and there's a new 500 crank on fleabay for just under a grand...not much between that and a fully refurbed (standard) bottom end from V8D...but the rest of my bottom end looks pretty mint...
Also been looking around at companies making steel cranks...I'd rather pay 1500quid for a bullet proof crank than a grand for one that could go pop any time...also at internal balancing against external and have the fly and harmonic balancer zero balanced or whatever it is.
Agree with anotehr recent post re con rods as well...the pistons have got SO much spare space at the top.
it;s only when you strip one of these you start seeing the compromises in there...but then I don't understand enough to really understand the hows and whys...
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