Bottom end rebuild

[Wobba]

Simple really: What do I need to renew all the parts with nice fresh stuff ideally?

Oil pressure on this block was not great, but the engine pulled really well.

Damage to the BE thus far is typical of a spun bearing. Wear on crank and the shells on that lobe were eaten up badly :(

Worth getting a new oil pump?

It's a F7R 700 by the way!

[robi1000]

It depends on your budget. You can buy brand new pistons (145€ each here in EU), definitely fit new piston rings (around 60€), new crank or regrind and polish old one (about 120€), new shells and new main bearings (25€ + 25€). If you regrind the crank just be carefoul to buy the right shells (1st grind or maybe even 2nd grind, depends on how much material was taken from the crank). Also you must rehone the block (around 100€) if you want your new rings to bed properly. Provided that bores are not worn too much. If that's the case, then you need a rebore and oversize pistons. Maybe a good chemical block cleaning wouldn't hurt too. It will get all the dirt out of your oil and water ways, improving heat transfer and flow.

You can measure how much wear there is on the pump. If it's ok then just clean it, if not get a new one. You can get yourself a nice Gr.A oil pump spring for even higher oil pressure. 8)

That's it from the top of my head. You can always get fancy and harden your crank (about 50€, but it's risky since your crank can bend) and put some low friction coating in the bores. :lol:

[Coops]

honing is no way that much, i had my old bottom end fully chemical cleaned and honed for 30 quid at a an engineering place in rotherham. i stripped the block first and took it in

[robi1000]

Well, prices are not exact. Usually I do more jobs at once and I pay the whole bill. These numbers are from memory. It also depends what is rehoned. Solid block or sleeves. With sleeves there's a bit more work, because you have to compress them while rehoning so that you get them straight once in the engine. But this are the small things you do if you want to squeeze every bhp out of the engine. Usually they just clamp the sleeve in and rehone it. That's it. Job done. Much cheaper. :lol:

[16v_paddy]

Labour wise, I got quoted £95 for the crank to be polished, block re-honed and the whole bottom end put back together

[stan]

Tip:

I REALLY wouldnt get the crank micro-polished then use std size shells, the clearances WILL be too larger and oil pressure will suffer.

The best thing to do, is buy some 0.25mm undersize shells, then give the machine shop your own diameter for the journals to be ground to, based on your measurments and the oil clearances you desire. They are on the upper limit of the oil clearance from the factory, and ANY pissing about with the crank and std sizes exagerates this.

If you want any more advice on this feel free to email/call me...ive seen LOTS of people do it the "quick" way and they are never 100% right!

[stan]

Labour wise, I got quoted £95 for the crank to be polished, block re-honed and the whole bottom end put back together

Where was this??!!!

[16v_paddy]

Labour wise, I got quoted £95 for the crank to be polished, block re-honed and the whole bottom end put back together

Where was this??!!!

Local engine builder, told me £40 for the crank polish & £45 for the rest if I supplied all the parts :?

[Wobba]

Labour wise, I got quoted £95 for the crank to be polished, block re-honed and the whole bottom end put back together

Where was this??!!!

MacDonalds.

[Wobba]

Thanks everyone. Stan: I may drop you a line anyway as I wanted to get a quote for something else.

Thanks Robi, I KNOW you've had fun with engines :D

[jw]

i recently had my crank re-ground and they also supplied the bearings this cost around the £150 mark, had the head also skimmed for an extra £30, as for the oil pump i changed mine but reno only im affraid just shy of £200, as for the rings i have a low miler 54k, so had second thoughts about changing the rings renault wanted to relieve me of £240, would have changed though if the car had done well over 100k, hope this helps


john.

[robi1000]

Stan is right. Polishing isn't the best idea, but sometimes if damage is minimal it's fine. I forgot if F7 series have hardened crank from the factory (I think not), but if they don't it doesn't really matter if you go for first grind. I always get them to check if crank is straight and balanced just to be sure.

[Wobba]

Thanks guys, I'll put my thinking cap on and work something out!