Putting a 4.5 engine into a 4.2, what else is req?

[Sophiefatale]

I've had my (husbands) 4.2 for a few years now and it's getting to the point where an engine refresh/rebuild might be due.

I'd really love a 4.7 but I can't justify the cost for what would be bragging rights. I don't do trackdays, don't really drive that fast but I just love the look and sound.

I was thinking about obtaining a second hand 4.5 engine. Apart from the engine, what other things would need to be replaced? I think the exhausts are different sizes but is there anything else such as gearboxs, props, driveshafts, ECU's etc that would need to be changed?

What would be best:-

(1) Original engine rebuild
(2) Buying a 4.5 and doing an engine swap

[camel_landy]

I'm sure the more knowledgable will be along shortly to correct me but I'm fairly sure it'd drop straight in!

M

[Supateg]

A 4.2 will be putting out more Bhp than a standard or poor 4.5.

Food for thought.
How about a 4.2 refresh with light tuning and a remap?

Worth talking to Andy @ APM for options.

Main difference between 4.2 and 4.5 is air intake from the cylinder head and airboxes. Exhaust is a tad smaller diameter.

I think a 4.2 rebuild, using 4.5 inlets, port matching, ACT full 4.5 system and mapping will be a job well done.

Gearbox same, electrics same, same propshaft, same driveshafts,

Mostly same lol

[FarmyardPants]

I would also advise talking to Andy at APM about options if it is in need of a rebuild (out of interest, what makes you say it might need one? Is it using oil, smoking, noisy...?)

This is going to be by far the easiest, cheapest, quickest and most convenient option.

If you have it rebuilt and remapped you should also pick up a bit of performance and drivability. No need to change the engine in its entirety, they are hard to come by.

[Sophiefatale]

It's a 1997 with 64k'ish miles on the clock, I think it's in need of a rebuild due to a leak test. I've got a couple of pistons down, it uses oil and has a little bit of smoke on hard acceleration.

I'm not really into trackdays, this car gets such an easy life with me, it's used every day for just cruising around making pops and bangs. As a result, I keep an eye on the oil and it's not getting any worse, it drives fine but I know I'll have to get it sorted eventually.

I keep looking at the 4.2 engine on ebay and thinking if that were a 4.5, I could swap them over and strip my 4.2 for parts (or sell it complete) to get a bit of cash back and treat myself to Nitrons.

BTW, I know the history of the Ebay seller etc etc - I was thinking more along the lines of a reputable person selling a 4.5 engine if there was one available.

[neutral 3]

I have a pal who has a low miles Cerb engine, a while back I was thinking of having it for the Griff. Can't remember if it's a 4.2 or 4.5, but will contact him for more details.

[900T-R]

If you like the character of the 4.2 you could do worse than refreshing the engine and putting 4.5 inlets with a short induction kit on top. This way you'd know that you're starting with a clean slate again - unlike when replacing the original engine with an unknown quantity, and the improvement should be well sufficient to rekindle your love affair with the car

[tejr]

A '97 4.2 probably has the aggressive clatter cams (like my old one).. I wouldn't have swapped that for a boring 4.5

[natben]

Personally I would go with getting your 4.2 refreshed rather than picking up a used 4.5.
At least you will know you have a good new engine in it rather than picking up a used 4.5 that you be unsure of the history of it.

[fr0zent0ast]

What is the difference in an "engine refresh" and an "engine rebuild" in terms of what is done and the cost?

[900T-R]

There's no 'hard' definition of what constitutes a 'refresh' and the point where it becomes a rebuild - often people will refer to the engine having had a 'rebuild' when ll they've had done is a head gasket and timing chain change and a clean up of the cylinder head(s) - but I'd expect a refresh to retain all the major engine parts - pistons, rods, crankshaft, valves - and to include new bearings, rings, gaskets, cylinder bore hone and a valve/valve seat refinishing job.

[Superjuiced]

If buying a second hand engine without seeing it run is a big risk especially if your looking at subbing out all your engine work. you could spend a lot more buying and refurbing a new engine than It would cost you to have a rebuild. If your not chasing 1/4 mile times then why not have your existing engine rebuilt and well tuned which will give u plenty of power without breaking the bank.

[Jhonno]

I would go with the refresh/rebuild myself..

[itsallyellow]

Call Andy at APM. The only differences are the throttle bodies and air boxes. I happen to have a few sets of 4.5 pistons and liners......

Mike