Backyard Engine Rebuild

[Twinky]

Ok so it's now time to step it up a notch in the backyard mechanic skill set.

My 5K engine is slowly starting to fall apart and with the recent addition of a crack in the water jacket, suggesting head warpage

I have decided the engine is need need of either binning or a DIY rebuild. I say DIY because of two things, one is that a low K

5K engine is damn hard to find locally and is usually over priced. Or two, the professional rebuilds are too expensive for what it's worth.

 

The head work will be done by professionals as the price is great, $110 - $150 for reface + valve and valve seat re grind + crack test.

I paid $110 to do that on my 4k but that was two years ago.

 

I have priced up a simple rebuild kit from sprints.

 

VRS kit $68

Piston rings $55

Main bearings $50

Optional new piston set $150

 

I have not yet priced up a hone or ring compressor yet but I would say around $200 should cover that.

Then probably another $200 for disposable materials ie gasket silicone, rags, lubricants etc etc...

 

So..... How hard is it to do? Can it be done at home with the proper tools? Can you suggest any other unique tools that I will need?

I have gone through a couple of DIY rebuilds on the net and all the intricate bits are mostly in the head work with the block

being the shortest time spent and least difficult.

 

So my plans so far:

 

Take a week off work, order parts and tools except for the new pistons as I will only need new ones if the old ones are worn to buggery.

Dismantle engine, clean the shite out of the engine bay and engine parts & accessories. Pull head off and throw in the bin, get spare head and

throw it at TW engineering. Pull apart block, clean, inspect, put new stuff in, put it all back together, profit??

 

So, the million dollar question.

Should I attempt it? I'm not new to engines and am a fast learner.

I've done things by halves before and I'm tired of fixing small issues down the track.

I want to do this right and once only. If I want this thing to live to become my daughters first car in 16 years

I want it to last.

 

Cheers

 

Alexey

[B.L.Z.BUB]

I have a 5k head if you need one.

Edited March 9, 2012 by B.L.Z.BUB

[Twinky]

I know that there are two different sizes of pushrods for the 5k,

is that because of a difference in the block head or rocker gear though?

Just I wouldn't want to get the head and find out that I can't use it.

 

cheers

[ke70dave]

if your engine is running reasonably well, then you can just get your current head overhauled.

 

drop it off at a machinest, pick it up looking brand new, pressure tested, valve grinds done, everythign ready to go.

 

thats the top end sorted.

 

bottom end really depends on the condition, if everything is within tollerance, buy some new bearings, pistons and rings, plastiguage everything to make sure, bolt it together with a torque wrench.

 

fun times come when cranks need grinding, bores need over sizing, etc.

 

but a machine shop will be able to supply you with the bearings/pistons/rings you need, machine things to the required size, then you just check it all with plastiguage and bolt it together.

Edited March 9, 2012 by ke70dave

[Jono.C]

You're missing big end bearings off that list

[Twinky]

thought it was the same thing

[SLO-030]

I got a complete 5K in bits here if you want to get it outta my shed?

[Twinky]

How much kind sir?

[Twinky]

PM sent

[Jono.C]

thought it was the same thing

 

Afraid not. Mains are the crank shaft caps and big ends are the rod bearings

[altezzaclub]

That would be best, build a spare and swap it over. Failing that, get the second head done and ready to go before you pull the current one apart.

 

Get the flywheel lightened and the whole lot balanced while you have the crank out.

 

You'll need a ring compressor if you have the pistons out, and a torque wrench. Buy the torque wrench but borrow or hire the ring compressor.

 

I don't know how the gudgeon pins are mounted on the con rods, but If you fit new pistons have a machine shop do it if they are pressed in. That's too easy to ruin at home.

 

Pay a machine shop to clean everything, especially the block. If you need it rebored or honed they will do it, but if not just take all the bits in after you've pulled it apart and get it all cleaned in a bath. Get back the parts cleaned, the new pistons on the conrods, and assemble it all at home.

 

I can't see it being done in a week unless you pre-order parts and have the machine shops ready to do the engineering at a day's notice.

[snot35]

I've got a ring compressor somewhere, PM me. A rebuild is pretty straight forward if you're patient and methodical. I might be able to help with other tools too as I've done builds before. I would lend my torque wrench but to be honest, I'm not sure of it's accuracy these days.

 

As altezza said, tell me machine shop what you want to do. If you're going to a good one they'll advise what's toast and what's good and get everything finished suitably for assembly.

 

Edit: I have a hone too. Also, the differences in pushrods are from different head heights. Shallow dish 5K's have a taller conventional head (like 3K 4K etc), D or deep dish have shorter heads. I think the difference was 6mm or something?

Edited March 9, 2012 by snot35

[philbey]

TW are good dudes, Wayne is a gun.

Edited March 12, 2012 by philbey

[Twinky]

Yeah I have a torque wrench, it's not point perfect but even the specs from the books wouldn't be something to

go point perfect for because of wear over the years would change what the torque setting needs to be anyway.

A ring compressor will only set me back about $15 and a hone about $30.

 

Depending on how much SLO 030 wants for his 5k will govern how I go about this. If the price is good I'll go for his engine

and basically push it towards the guys at TW and get them to look over it, do the full head work and maybe just skim the block

if it isn't square. I don't think I'll go as far as a full balance but I'll keep it in mind. I'm only really looking to do the

necessary bits first. I don't thrash the motor as it is and when I go supercharged It won't go past 4500rpm either.

 

If I don't get his engine I'll still take the week off but only the week that I get all the bits back. I can bus it to work

quite comfortably.

[B.L.Z.BUB]

If you do it in a week I'll buy you a beer, but you must drive it to work.

May as well twin carb it too :D