Reboring Question

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Discussion

danhay

Original Poster:

7,467 posts

263 months

Sunday 4th January 2004
quotequote all
How much should it cost for a V8?
Do you always need new pistons too?

In my case it's general wear rather than any sort of catastrophic failure.

Mr2Mike

20,143 posts

262 months

Sunday 4th January 2004
quotequote all
danhay said:
How much should it cost for a V8?
Do you always need new pistons too?

In my case it's general wear rather than any sort of catastrophic failure.


Don't know the cost, but reboring always entails the use of new pistons/rings.

350zwelgje

1,820 posts

268 months

Sunday 4th January 2004
quotequote all
Perhaps you don't need a rebore, but "honing" of the cilinders (depends on tolerances). In this case you could perhaps get away with just new piston rings.

But others perhaps can help you in more detail.

Don't know about the costs either. But just honing instead of a rebore (you need honing always as a finish) is not difficult and will cost less.

Rob

Boosted LS1

21,198 posts

267 months

Sunday 4th January 2004
quotequote all
Have you a ridge at the top of the bores, if so you need a rebore. Typically about £10 per cylinder and the honing is included in that price. Cash may get you some discount.

danhay

Original Poster:

7,467 posts

263 months

Monday 5th January 2004
quotequote all
I haven't had the heads off yet, so have no idea whether it's a just a hone or if it will need a full rebore. The problem is pistons cost £150 each

grahambell

2,718 posts

282 months

Monday 5th January 2004
quotequote all
danhay said:
The pistons cost £150 each


Well if you will go buying Ferraris...

If you do find a ridge at the tops of the bores, then with pistons at that price it could be worth asking about getting the bores sleeved instead. Think you'd need to ask either a Ferrari specialist or top notch engine builder rather than local reconditioners from Yellow Pages though.

danhay

Original Poster:

7,467 posts

263 months

Monday 5th January 2004
quotequote all
After a bit of investigation, it appears that the engine has liners, and that these can be replaced without having to rebore. Liners are 'only' £95 each. Though I assume a new set of piston rings should be fitted too.

Can anybody reccommend an engine specialist in the South East?

nonegreen

7,803 posts

277 months

Tuesday 6th January 2004
quotequote all
danhay said:
After a bit of investigation, it appears that the engine has liners, and that these can be replaced without having to rebore. Liners are 'only' £95 each. Though I assume a new set of piston rings should be fitted too.

Can anybody reccommend an engine specialist in the South East?


The liners will still have to be bored after installation surely? You will still need to replace the worn pistons also.

GavinPearson

5,715 posts

258 months

Tuesday 6th January 2004
quotequote all
danhay said:
After a bit of investigation, it appears that the engine has liners, and that these can be replaced without having to rebore. Liners are 'only' £95 each. Though I assume a new set of piston rings should be fitted too.

Can anybody reccommend an engine specialist in the South East?


If the liners are dry they need boring after fitment.
If the liners are 'wet' like in a Jag V12 they should not need boring.

If the car is the Ferrari as in your profile why not go to somebody who is renowned for doing the job right that all the specialist engine builders get their machining work done at. I recommend Chesman Engineering in Coventry - 02476 689665 - they do lots of Jag and Ferrari work, and balance crankshafts for Ilmor Formula One engines. And they're cheap.

blackzr

280 posts

253 months

Tuesday 6th January 2004
quotequote all
Chesmans are really good, I have used them for all our machining work for around 10 years. Give them a ring ask to speak to Steve he runs the shop. They do a lot of specialist work including making liners.

danhay

Original Poster:

7,467 posts

263 months

Tuesday 6th January 2004
quotequote all
Well, in my workshop manual it says:
"Liners are free assembled in their housings. They are supplied ready to assemble, that is with prescribed allowances"

So I'm guessing they're wet liners. Also there is a void behind part of the liners for water or oil?

I would prefer to go direct to an engine specialist, so thanks for the reccomendation.

grahambell

2,718 posts

282 months

Tuesday 6th January 2004
quotequote all
nonegreen said:
The liners will still have to be bored after installation surely? You will still need to replace the worn pistons also.


Disagree about the pistons. If they're in good condition (i.e. no bad scuff marks or wear in the ring grooves) then you should be OK just giving them a clean up and new set of rings.

numbnuts

602 posts

255 months

Tuesday 6th January 2004
quotequote all
One thing to remember when your fitting your liners ,
if there wet liners make sure they have the correct shims/o rings at the bottom to maintain the correct hight in the block.
sometimes liners can sink into the block and you can only fit one shim in most cases.
If you dont have the correct hight you may have to machine the face of the block.