1994 1.8 engine rebuild

[KevSeymour]

I posted this on Nutz but the thread seems to have gone stale so thought i'd try you knowledgable folks as well...

I've never done any proper engine work before, so i'm thinking about getting hold of a cheap 1.8 to fully strip and rebuild for no better reason than to learn how to do it.

I just got the Rob Grainger book for my birthday, which might have something to do with this.

What i'm looking for is a list of parts to replace, things to check while it's apart and any cheap mods that can be done to improve performance, economy or durability. For example, having the flywheel lightened (I'm aware it's a contentious issue but i've had a lightened flywheel on a previous car and loved it), and the exhintake mod.

I've done some research already and come up with the below list, please feel free to add to it or provide any advice you think worth hearing.

Replacement Parts
Head
Gasket/seal set
Head bolts
Cam followers
Cam bearings
Valve stem seals

Block
Gasket/seal set
Piston rings
Rod bearings
Main bearings
Thrust washers

Ancillaries
Filters
Belts
Idler Pulley
Tensioner Pulley
Water pump
Oil pump
Clutch

Mods
Lightened flywheel
14° timing mod
Exhintake
Crackle paint cam cover, cambelt covers, inlet manifold
Silicon hose kit

[scrwright]

get a 99-00 head, they are better flowing than the earlier ones

[KevSeymour]

There's potential in that idea, but it would depend on the cost of the head - i don't want this to become a £1000 engine rebuild.

Are the exhaust ports the same on those heads, could i use the same manifold?

[scrwright]

KevSeymour said:

i don't want this to become a £1000 engine rebuild.

have you priced up your shopping list? I'd say well over £500 of bits at a rough guess, would have thought close to a grand TBH

While it is in bits would be worth balancing it.

Manifolds are different on the 99-00 head

[scrwright]

just had a quick scan on mx5 parts

cam followers, £27
valve seals, £8
piston rings £140
crank bearings £60
big end bearings £45
timing belt kit £65
water pump £50
gasket set £280


there goes a grand!

[KevSeymour]

I haven't got as far as pricing it up yet, no, but i'll do the essentials then see what else I can do and keep the budget reasonable.

Are the manifolds different because the branches need to be, or because the exhaust ports on the head are different?

[scrwright]

ports are higher, steeper/straighter run into the chamber.

What are you trying to acheive?

Get a 99-00 engine, new pump/cam belt, do the flywheel & general cleanup, plus decent exhaust manifold. Will be alot less than a rebuild on a '94 engine and will be IIRC about 15bhp up on the earlier motor

[ronime]

KevSeymour said:

i don't want this to become a £1000 engine rebuild.

Then don't do it. It will be well over a grand if you build it properly (if you hone the bores properly then you will need oversize pistons). Not worth it to end up with another 130bhp engine.

[KevSeymour]

HA! I've just gone through the MX5Parts website and got prices on everything....£1591.82, and that's without anything from the mods list.

Head
Cam followers	432
Valve stem seals	128.88
Camshaft oil seals	14.02
Crankshaft front oil seal	5.51
Block
Piston rings	145.85
Rod bearings	66.2
Main bearings	79.05
Thrust washers	18.41
Ancillaries
Filters	11.98
Complete gasket set	280.24
Auxilery belts	13.44
Cambelt kit	63.58
Water pump	54.62
Oil pump	168.26
Clutch	109.78
Total	1591.82

So yeah, to do it "properly" would be prohibitively expensive just for the heck of it, it would be nice to have a completely fresh engine but not at that price. Obviously there are ways to cut down the spending but then i wouldn't really be learning enough for the outlay and effort.

I guess i'll have to find a different project, might learn to weld instead...

[MX-5 Lazza]

I'm sure those prices would be a fair bit cheaper at a motor-factors.

[snotrag]

It can definitely be done for lots less than that, I looked seriously into it when I had my mk1.

I also have a complete 99 head, with all the required bits to fit to a mk1, as this was what I was going to do. Only have it spare as I bought a full mk2 car in the meantime. Will let it go cheap...