Author Topic: Bottom End?? (Read 3498 times)

Jamieg285 · « **on:** January 16, 2006, 07:34:32 pm »

Bum
Say's it all really.

Took my spark plugs out on Sat, good thing I did, they were thick in carbon - explains the poor running in the cold lately.

Cleaned 'em up, opened the gaps, shoved 'em back in. Scared the neighbours by getting 4 plug leads on back to front (Gives some excellent back fires!)

Stuck on my new Accel air filter and took her for a (energetic) test run to Hitchin and back.

Good news - running smoother than ever, even in the cold/damp of this morning.

BAD NEWS The timing cover oil seal is still leaking, even worse when I push the engine up over 3K. It can't be the seal, as it's only a couple of months since I changed it, so I can only conclude the crank is worn where the seal sits.

Roadkill · « **Reply #1 on:** January 16, 2006, 07:57:26 pm »

Bottom end, then ?

That sucks. You've a 400ci in there don't you ?

55starchief · « **Reply #2 on:** January 16, 2006, 08:45:23 pm »

well if the cranks worn, why not stroke that puppy with a new crank

Jamieg285 · « **Reply #3 on:** January 16, 2006, 09:18:08 pm »

Yes, it's a 400.

I have heard about offset seals to deal with this problem, but I haven't been able to find one yet.

How much work is a bottom end rebuild? I have never considered doing one before, and don't know exactly what would be involved.

Yes, a new crank and rods and pistons (in fact when I'm done, I think the only original part will be the block!!), but only when the work is required.

Roadkill · « **Reply #4 on:** January 16, 2006, 09:32:04 pm »

How bad is the leak ?

Jamieg285 · « **Reply #5 on:** January 16, 2006, 09:34:44 pm »

Quoting: Roadkill

How bad is the leak ?

Looks bad, but is really only bad when you stess the engine.

Under normal conditions, it ain't too bad.

Put another way, after a 'decent' run on the dual carriage way (10 round trip), half the engine bay was covered.

55starchief · « **Reply #6 on:** January 16, 2006, 09:46:15 pm »

Bottom end should be no harder than top, although you will need to remove the heads to change the crank, it can be done without and i have heard of people changing the crank with the motor still in the car

Jamieg285 · « **Reply #7 on:** January 16, 2006, 09:59:46 pm »

If I'm going to the effort to change the crank, I want to change the whole lot, so realistically it's engine out. If I'm lucky it won't need machining, but until I get the heads off I won't know.

I suppose it is feasible to pull the engine and do the complete bottom end replacement and get it back in, in relatively short time, but that is dependant on the bores being good.

55starchief · « **Reply #8 on:** January 16, 2006, 10:01:16 pm »

Quoting: Jamieg285

I suppose it is feasible to pull the engine and do the complete bottom end replacement and get it back in, in relatively short time, but that is dependant on the bores being good.

yup, a weekend job if you have ALL THE PARTS and no machining needs to be done, we managed a top end build on deans in a morning, just took a weekend to paint it and re assemble

Roadkill · « **Reply #9 on:** January 16, 2006, 10:06:36 pm »

Quoting: 55starchief

just took a weekend to paint it and re assemble

Then dis-assemble.

Jamieg285 · « **Reply #10 on:** January 16, 2006, 10:24:53 pm »

Quoting: 55starchief

yup, a weekend job if you have ALL THE PARTS and no machining needs to be done, we managed a top end build on deans in a morning, just took a weekend to paint it and re assemble

OK, then what are all the parts required (to double check my own thoughts - my list below)

I guess at some point I will need to pull the heads off and check the bores. Is there anything more than head gaskets that I sould get for doing this?

Bottom End rebuild list:
Crank
Pistons (

Piston ring sets (x2)
Con rods set (installed on pistons)
Main and rod bearings
Rear Main seal
Timing cover seals & gasket
Sump gasket
Head gaskets

What have I missed

Roadkill · « **Reply #11 on:** January 16, 2006, 10:26:23 pm »

Get a full Gasket set - It'll give you EVERYTHING you need and will cost ALOT less then buying odds . . . .

Roadkill · « **Reply #12 on:** January 16, 2006, 10:26:55 pm »

Oil pump / kit ?

Jamieg285 · « **Reply #13 on:** January 16, 2006, 10:27:33 pm »

(moving to Projects)

55starchief · « **Reply #14 on:** January 16, 2006, 10:29:05 pm »

rod bolts as the old ones will be streched

Jamieg285 · « **Reply #15 on:** January 16, 2006, 10:29:14 pm »

Quoting: Roadkill

Get a full Gasket set - It'll give you EVERYTHING you need and will cost ALOT less then buying odds . . . .

Thinking about it, I've already got a bottom end set, obviously there will be a few bits missing though (heads for one)

Jamieg285 · « **Reply #16 on:** January 16, 2006, 10:29:47 pm »

Quoting: Roadkill

Oil pump / kit ?

Good point, was on the list, just forgot about it.

Jamieg285 · « **Reply #17 on:** January 16, 2006, 10:30:17 pm »

Quoting: 55starchief

rod bolts as the old ones will be streched

I thought they came with the rods. Maybe it depends on which rod set?

55starchief · « **Reply #18 on:** January 16, 2006, 10:31:41 pm »

oh sorry mate, thought you meant you were using your old set

Roadkill · « **Reply #19 on:** January 16, 2006, 10:32:14 pm »

Good to have spare gaskets . . .

I Don't think it's worth installing fresh pistons into old pots, though, Mate.

I know it'll take longer and cost more but if your bores are a bit worn they'll just bugger up your new pistons and you'll lose compression.

55starchief · « **Reply #20 on:** January 16, 2006, 10:33:18 pm »

well seeing as this is now a rebuild a see a new cam

Jamieg285 · « **Reply #21 on:** January 16, 2006, 10:33:39 pm »

Quoting: Roadkill

I know it'll take longer and cost more but if your bores are a bit worn they'll just bugger up your new pistons and you'll lose compression.

So you reckon I should definitely overbore if I am putting new pistons in?

Jamieg285 · « **Reply #22 on:** January 16, 2006, 10:34:22 pm »

Quoting: 55starchief

well seeing as this is now a rebuild a see a new cam

Later, I'm on a budget.

Beside's my 'Good for Towing' cam is fine as it is.

Roadkill · « **Reply #23 on:** January 16, 2006, 10:34:39 pm »

Quoting: Jamieg285

So you reckon I should definitely overbore if I am putting new pistons in?

Defo.

55starchief · « **Reply #24 on:** January 16, 2006, 10:34:42 pm »

Quoting: Jamieg285

Quoting: Roadkill
I know it'll take longer and cost more but if your bores are a bit worn they'll just bugger up your new pistons and you'll lose compression.

So you reckon I should definitely overbore if I am putting new pistons in?

yup,

the bores might be oval, so a rebore would help and go .30 over for some added capacity