Gearbox question

Hi all not been on for a while! hope all the locals are well.I'm looking to put a new engine in my 4ltr p38, but thought
about putting 4.6 instead, will the original gearbox be ok or would it
have to be replaced because of the bigger engine size.

Different size GB but you have room for it, look in RAVE size your 22 vs. 4.6 24

It's not just the physical size. The HP22 was fitted to the 4.0 but they fitted the HP24 to the 4.6. The 24 is a much stronger box internally.

Is the 4.6 a physically a bigger engine?

tonybirch said:

Is the 4.6 a physically a bigger engine?

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It's the same block.

So really then and I'm guessing here, is the box capable of taking the extra power?

tonybirch said:

So really then and I'm guessing here, is the box capable of taking the extra power?

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The HP22 boxes are also fitted to the diesels and are known to fail if you chip the engine. So I'd say that it's pretty certain that they won't handle a 4.6, not for any time anyway.

That was my suspicion!

If you're determined why not see what a breaker would charge for an engine complete with box? Just make sure that you get a warranty against it having been cooked or having a slipped liner.

Nope no breakers engines. Theyre two unreliable these v8
It's gotta be a new block with top hats. Was gonna get it from v8 developments

Well if you're spending that sort of money you could talk to Ashcrofts about the box. They might do you an exchange 22 for 24 or they do upgrades to the 22 to handle more power. They could also advise you about the physical size.

Other gearbox companies are available but they're the only one that I know that the internal upgrades.

Yea ill do that, thanks for the advice.

You should be able to swap the HP22 for the HP24, overall they are the same length and the ECU from you 4.0 will work fine with the HP24, you will also need to use the correct torque convertor and bell housing for the 4.6.

I have a spare ecu for a 4.6 kicking about if needed

Druim said:

I have a spare ecu for a 4.6 kicking about if needed

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That would not be compatable with the wiring in the 4.0 as it uses a different system.

So really then, the best bet is to go for a new 4.0l long engine!
Any idea who does good ones?

Turners have a good reputation.
It might still be worth getting your box rebuilt at the same time, they do run a bit close to their limit and if it's got a few miles on it . . . . .

Ill speak to turners! If anyone knows of company's who have a good rep
for recon top hat long engines let me know please. As per usual top draw advice from the locals! Thanks

You could ask MOZZ, he's just had his engine re-built - and he's no fool.

Yea think I've got his number somewhere.