Bottom end rebuild - what am I in for?
Discussion
Hi all,
Having taken the oil pan off to investigate low oil pressure, my respected specialist says that my Griff 500 is likely to need a full bottom end rebuild. Apparently there's lots of wear.
They did the top end a couple of years ago so hopefully that won't need any work.
What do you think I might be in for £ wise?
Any recent comparable experience would be welcome.
Thank you!
Having taken the oil pan off to investigate low oil pressure, my respected specialist says that my Griff 500 is likely to need a full bottom end rebuild. Apparently there's lots of wear.
They did the top end a couple of years ago so hopefully that won't need any work.
What do you think I might be in for £ wise?
Any recent comparable experience would be welcome.
Thank you!
Are the mains and big end bearings down to copper. Has he even taken the crankshaft out to measure the wear using his Micrometer on the Mains and Big End journals of the crankshaft.
Has the crankshaft previously been reground.
It's basically how long is a piece of string.
The old saying many moons ago was, that if you did a top end recondition without doing the bottom, then the bottom end would wear out quickly.
Has the crankshaft previously been reground.
It's basically how long is a piece of string.
The old saying many moons ago was, that if you did a top end recondition without doing the bottom, then the bottom end would wear out quickly.
Yes, you need to see the damage, but a full rebuild from Dom is listed as £4K+VAT ( http://www.powersperformance.co.uk/upgrades/5L-REB... ). Assuming you can halve that just for the bottom end, then add the engine out/in costs you get to something like £3K+VAT as a ballpark.
As he has already done the top end, ask him if he can do the work without removing the engine from the car.
It ties up a ramp, but I believe it is possible.
Then you are just into new bearings and shells, and a crank grind, plus of course the labour and fluids - hopefully.
In which case it won't be earth shattering, but will be between £1k and £2k. The parts aren't expensive, but there is the cost of the re-grind (couple of hundred quid) and the labour and VAT. To be fair to your guy, it is easier to work on the engine on an engine stand because you can turn it upside down to work on it.
My TVR specialist did the top and bottom ends of my 4 cylinder Saab engine without removing it from the car, but he much preferred to do the bottom end of my RV8 out of the car.
It ties up a ramp, but I believe it is possible.
Then you are just into new bearings and shells, and a crank grind, plus of course the labour and fluids - hopefully.
In which case it won't be earth shattering, but will be between £1k and £2k. The parts aren't expensive, but there is the cost of the re-grind (couple of hundred quid) and the labour and VAT. To be fair to your guy, it is easier to work on the engine on an engine stand because you can turn it upside down to work on it.
My TVR specialist did the top and bottom ends of my 4 cylinder Saab engine without removing it from the car, but he much preferred to do the bottom end of my RV8 out of the car.
As others have said it really depends on what is in need of work.
If you cant swallow the cost of engine out and bottom end rebuild then........
What are the compression readings, has it been done yet ?
If its good (and as top end is done you can probably rule that out of the equation), it implies the bores/rings/pistons are in good order. That being the case you are left with bearings as wear points.
Replacing mains and big ends can be done engine in situ, although gearbox out for rear main.
If he suspects little ends then crank can still be removed engine in situ and pistons removed from below.
If you cant swallow the cost of engine out and bottom end rebuild then........
What are the compression readings, has it been done yet ?
If its good (and as top end is done you can probably rule that out of the equation), it implies the bores/rings/pistons are in good order. That being the case you are left with bearings as wear points.
Replacing mains and big ends can be done engine in situ, although gearbox out for rear main.
If he suspects little ends then crank can still be removed engine in situ and pistons removed from below.
Belle427 said:
May just need a bearing refresh, mine on a 400 were showing signs of wear at 80000, ok it’s not a 500 engine but don’t jump to conclusions.
This If you have shell wear you’d expect some on the crank but not necessary so dropping the sump and checking tolerances must be the way to go after a compression test as mentioned above. Sometimes a mechanic can just hear it and he knows roughly what’s the score so if bottom end rebuild was the basic prognosis I’d expect if this is a tuned Tvr ear listening he”s probably right.
ETA I should have read your post properly O/P
Lots of wear!
For some perspective my low mileage 450 engine had shell wear at 48,000 miles mostly put down to old oil not being changed often enough or hard acceleration before oil was upto temperature.
I had a regrind as part of a rebuilt engine off Dom 10 years and 25,000 miles ago, still sweet
Edited by Classic Chim on Sunday 11th October 11:10
If the engine is worn I wouldn't build up in situ, you need to remove to de-bung the oil galleries and clean correctly otherwise your going to jeapardize the whole rebuild , often many years of accumulated silt and containing abrasive failed cam lobes etc all there , filters don't stop minute particles sadly
phazed said:
I had low oil pressure on two occasions.
Firstly when a camshaft bearing decided to exit the block and spin around the camshaft. -10 psi
Then when the crankshaft broke near the first journal but still revolved with just a little bit of vibration! -10psi.
Don’t you just love RV8s!
I remember you being 10 psi'd off after the second one happened. Firstly when a camshaft bearing decided to exit the block and spin around the camshaft. -10 psi
Then when the crankshaft broke near the first journal but still revolved with just a little bit of vibration! -10psi.
Don’t you just love RV8s!
If I remember it broke in Snowdonia, the day before a track day at Angelsey, with your better half in the car too.
Apart from the wind all the way from Nova Scotia blowing straight through the garage, it was a fun day.
Just a shame it was without you.
Yes, that is correct. Such a shame after making the journey. It happened at a steady 50 mph in top gear!
Coincidentally, the camshaft bearing fell out as a track day at Cadwell Park.
These two instances where nothing to do with track days. It seems That the crankshaft wasn’t balanced well initially as my replacement made the engine much smoother. As for the camshaft bearing that decided to leave it’s home, it was one of the early split bearings and not one of the later fully spherical machined bearings. I will say no more......
Coincidentally, the camshaft bearing fell out as a track day at Cadwell Park.
These two instances where nothing to do with track days. It seems That the crankshaft wasn’t balanced well initially as my replacement made the engine much smoother. As for the camshaft bearing that decided to leave it’s home, it was one of the early split bearings and not one of the later fully spherical machined bearings. I will say no more......
Gassing Station | Griffith | Top of Page | What's New | My Stuff