Broken Crank Shaft

Broken Crank Shaft

Author
Discussion

gruffalo

6,660 posts

193 months

Sunday 13th June
quotequote all
itsallyellow said:
The 4.7 is more drivable, has more power and has more torque.

There is not one thing a 4.5 does better than a 4.7.

I have lots of experience of both engines. I now have 4 cars with 4.7 AJP’s and one with a 4.5

Mike
This is absolutely correct, the difference is amazing for just 200 cc increase.

The 4.7 is better in every respect.

gruffalo

6,660 posts

193 months

Sunday 13th June
quotequote all
DuncanM said:
Gruffalo your Cerbera sounds incredible! Smiling from ear to ear reading about it smile.

OP, good luck with your repair smile
Thank you, it has been a 13 year program with the aim to make it as good as it can be, I think I am there now.

Upgrades and on going maintenance over the years are probably nudging 6 figures however but worth every penny.


DuncanM

4,320 posts

246 months

Sunday 13th June
quotequote all
gruffalo said:
Thank you, it has been a 13 year program with the aim to make it as good as it can be, I think I am there now.

Upgrades and on going maintenance over the years are probably nudging 6 figures however but worth every penny.
I consider the Cerbera as one of the greatest cars ever made (yes I'm bias hehe) - you must have one of the finest examples on the road, so, worth every penny indeed smile.



Dave0

1 posts

Wednesday 14th July
quotequote all
Sorry to hear about your engine!

Is there any way of telling whether you have the earlier small crank or is it just a case of hope for the best?

I'm potentially looking at a may 97 registered car and want to know how likely it is.

I've tried searching forums and some mention the dipstick position as a tell. Any light on this?

Jhonno

4,033 posts

108 months

Wednesday 14th July
quotequote all
Dave0 said:
Sorry to hear about your engine!

Is there any way of telling whether you have the earlier small crank or is it just a case of hope for the best?

I'm potentially looking at a may 97 registered car and want to know how likely it is.

I've tried searching forums and some mention the dipstick position as a tell. Any light on this?
No definite way of telling..

As Thomas' was an early early 4.2 it had the small journal crank that suffered with the cracking issues. A '97 will be the later better version.

thomas.moeller

Original Poster:

83 posts

179 months

Wednesday 14th July
quotequote all
Mine is a 1996 and orginally fitted with the early version crankshaft. Unfortunately, I don't know when the upgraded version was rolled out, but I suspect it was when the 4.5 was released.

RUSSELLM

5,737 posts

214 months

Wednesday 14th July
quotequote all
Dave0 said:
Sorry to hear about your engine!

Is there any way of telling whether you have the earlier small crank or is it just a case of hope for the best?

I'm potentially looking at a may 97 registered car and want to know how likely it is.

I've tried searching forums and some mention the dipstick position as a tell. Any light on this?
There’s been some crank failures over the years, but very few.

Of the various concerns when buying a 97 Cerbera, the crank would be quite low down the list for me.

Mines been zooming round for 25 years and 69k miles. If it snaps now, I feel I’ve had my money’s worth out of it smile

davo23

270 posts

119 months

Thursday 15th July
quotequote all
Thanks chaps. Used to have a Chim and I forgot how helpful the tvr community was.

Thomas I hope you get it sorted soon and it isn't too painful.


Byker28i

35,528 posts

184 months

Thursday 15th July
quotequote all
Mine was a 97 engine with a small journal crank and I had no issues. My valve guides wore so I got the engine refreshed and rebuilt and had to convert to the later large journal crank because noone would warranty my engine without it

Jhonno

4,033 posts

108 months

Thursday 15th July
quotequote all
thomas.moeller said:
Mine is a 1996 and orginally fitted with the early version crankshaft. Unfortunately, I don't know when the upgraded version was rolled out, but I suspect it was when the 4.5 was released.
It was in '97 at some point..

Chimp871

837 posts

84 months

Thursday 15th July
quotequote all
check the sump plug. if it has 2 then it's small journal IIRC, not YMMV but somewhere to start.

threespires

3,827 posts

178 months

Thursday 15th July
quotequote all
Byker28i said:
Which is strange as that's when most cerberas were built? Worth pointing that out?


Is there any info on the 2 Cerbera's built in 1994?

RUSSELLM

5,737 posts

214 months

Friday 16th July
quotequote all
Looking at the other models on the list, I can’t see another where they built cars, had a year off, then started building again.

So I’d question the accuracy of the ‘2’

They don’t exist on the ‘how many left’ website, I that helps.


Jhonno

4,033 posts

108 months

Friday 16th July
quotequote all
Chimp871 said:
check the sump plug. if it has 2 then it's small journal IIRC, not YMMV but somewhere to start.
If it is 2 it is an early small journal..

Byker28i

35,528 posts

184 months

Saturday 17th July
quotequote all
Jhonno said:
thomas.moeller said:
Mine is a 1996 and orginally fitted with the early version crankshaft. Unfortunately, I don't know when the upgraded version was rolled out, but I suspect it was when the 4.5 was released.
It was in '97 at some point..
Mine was May 1997, small journal crank originally.

Chimp871 said:
check the sump plug. if it has 2 then it's small journal IIRC, not YMMV but somewhere to start.
Mine has one sump plug...

Davo23

270 posts

119 months

Saturday 17th July
quotequote all
Byker28i said:
Mine has one sump plug...
And yours went and needed a rebuild?

Were there any signs beforehand or particular circumstances that led to it?




TwinKam

1,903 posts

62 months

Saturday 17th July
quotequote all
Davo23 said:
Byker28i said:
Mine has one sump plug...
And yours went and needed a rebuild?

Were there any signs beforehand or particular circumstances that led to it?
Dave's crank didn't break, he had his engine rebuilt for other reasons (valve guide mission creep? wink) but no one would warranty the rebuild without changing out his crank ...IIRC.

Jhonno

4,033 posts

108 months

Saturday 17th July
quotequote all
TwinKam said:
Davo23 said:
Byker28i said:
Mine has one sump plug...
And yours went and needed a rebuild?

Were there any signs beforehand or particular circumstances that led to it?
Dave's crank didn't break, he had his engine rebuilt for other reasons (valve guide mission creep? wink) but no one would warranty the rebuild without changing out his crank ...IIRC.
This.. He needed valve guides. Decided to do the lot whilst it was apart.. Crank was fine.

Byker28i

35,528 posts

184 months

Saturday 17th July
quotequote all
Brass Valve guides and chrome valves apparently on the early builds. Turn the heads upside down and two of the valves fell straight out. Put them back in and they rattled around... Compression was down 20% ish on 2 cylinders, so decided to get it fixed before it got worse. No sign of burning oil

Then, you know me, whilst everything was apart I decide to refresh everything whilst it was apart so it wouldn't need doing for ages... unfortunately that included the crank, because the 3 recognised builders wouldn't warranty it without changing to the later crank. No point spending all that money without using one of the credited builders, and without a warranty...

Davo23

270 posts

119 months

Sunday 18th July
quotequote all
That makes a lot of sense, thanks for explaining.

You'll have many years of happy motoring ahead