3.5 EFI reliability

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D90mitch

D90mitch

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So yeah, how reliable is this engine? Considering a conversion to it from the 200tdi. Wanted the 4.6 but learnt about the cylinder block / liner issues. Heard the 3.5 is the most solid of the bunch but what's it like in terms of reliability, on road, off road and in WATER :eek:
 
If you get a later block that has liner issues with top hats then its not a problem.

If you're buying an engine to convert from a 200TDi I would at least consider getting a known good engine and give it a clean out and new gaskets & bearings. In a way almost 'pointless' to do on a 3.5 if you haven't got a engine yet as sometimes you can get a 4.6 with top hat liners for a reasonable price, so rebuild that and you're good to go.

And as for what owl said, if you want to go 3.5 AND hotwire then go and find a Discovery with a 3.5 EFi engine - then you'll have hotwire and a 3.5. ;)

The 3.5 flapper injection system is about as basic as you can get in terms of EFi, you could only get more simple if you went for throttle body injection.

Or just do it the easiest way and get a complete engine with everything included and just drop it in & have no hassle of taking things apart etc etc.
 
Dr_evil said:
carbs is the way forth :D mines 9.75:1 I think or 9.35:1 and running an edelbrock 500, goes nicely and sounds meaty!
Click to expand...

If it was originally a 9.75:1 engine then look where the engine number is, should tell you. If 9.75:1 pistons were added then I hope you have a receipt to prove it! ;)

Also bollocks to carburettors! :p
 
marccleave said:
If it was originally a 9.75:1 engine then look where the engine number is, should tell you. If 9.75:1 pistons were added then I hope you have a receipt to prove it! ;)

Also bollocks to carburettors! :p
Click to expand...

It was an SD1 engine, checked the code but cant remember if it was 75 or 35, pretty sure it was 75 :p

cant see the ratio due to engine bay but once the manifolds are off I'll look
 
Sorry guys a bit of a nooby question, what is efi, it it expensive, what foes it have better over carbs and how hard is it to change from carbs to efi. (all q's for 3.5)
Burtie
 
Electronic Fuel Injection From memory 3.5 carb 137 bhp and 3.5 efi 150bhp approx

Depends how commited you are, more power,more economy
 
As fanatic said - much better! ;)

9.35:1 carburettor V8 is ~135bhp whereas 9.35:1 EFi V8 is ~165bhp.

So add 30bhp just for the difference from standard carburettor to standard efi.

It's not that expensive to convert, you can buy complete (standard) injection systems for <£200 easily. Better ones are available but more expensive, megasquirt - you can tune it...

Not difficult to change at all. You have to install a different fuel pump as EFi runs at a higher pressure. The major change under the bonnet is the inlet manifold which holds the injectors, fuel rail, ram housing, plenum chamber. The wiring for EFi is very simple as well, you need live 12V feed, ignition feed, cranking signal & feed to fuel pump off the top of my head.
 
marccleave said:
As fanatic said - much better! ;)

9.35:1 carburettor V8 is ~135bhp whereas 9.35:1 EFi V8 is ~165bhp.

So add 30bhp just for the difference from standard carburettor to standard efi.

It's not that expensive to convert, you can buy complete (standard) injection systems for <£200 easily. Better ones are available but more expensive, megasquirt - you can tune it...

Not difficult to change at all. You have to install a different fuel pump as EFi runs at a higher pressure. The major change under the bonnet is the inlet manifold which holds the injectors, fuel rail, ram housing, plenum chamber. The wiring for EFi is very simple as well, you need live 12V feed, ignition feed, cranking signal & feed to fuel pump off the top of my head.
Click to expand...

head ports need notching, simple enough with a die grinder etc
 
Burtie2904 said:
Sorry guys a bit of a nooby question, what is efi, it it expensive, what foes it have better over carbs and how hard is it to change from carbs to efi. (all q's for 3.5)
Burtie
Click to expand...

EFI - Electronic Fuel Injection.. Converting would be a bit of a job. Would need an ECU too.

HMMM V8's so irritating, they sound so great but they kick you in the arse at every opportunity. Can someone tell me more or give a link with more information about this hotwire?

Don't want carbs cos I want me engine to work off road :D - Do sound good tho...

I could probably make me 200tdi more powerful than a 3.5 efi standard. Probably not that far off now. Don't know how long it would last tho....
 
Last edited:
The difference is I like old school engineering. No issues with injection but the electrics are just another unreliable addition.

If they make a cam driven pump for injection like a tdi then problem solved but it'll never happen
 
That is the flapper type injection look for one with hotwire type air flow meter. I would look for a 3.9 with all the injection included, 3.9 is another 40 lbft I think the bigger bore unmasks the valves some.
 
Most if not all of the flapper air flow meters are faulty, last few I have looked at the CO adjuster does nothing. not worth bothering with when you can get the much better hotwire system.
 
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