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80 series 4litre vs 4.5litre

Posted: Mon Jul 20, 2009 5:40 pm
by khany427
hey all lookin at a couple 80series but want to find out a bit of info 1st.
one is a 90 model sahara 4 litre efi on dual fuel the other is a 93? model gxl 4.5litre on duel aswell.
now i know neither of them are the best on juice but im not overly worried about that (hence the lpg) but out of both of them which would be better on fuel? (lol that sounds like a bit of a contradiction of terms! but you get what i mean)
both are autos and have around 300kays aswell.
i know the whole get a manual and diesel stuff but i am on a budget with a mortgage and dont want to take out another loan to get something better in this economic climate, so is all i can afford! there is manuals around for the same price but want an auto so is easier for the cook to drive.

i currantly have a 60series sahara 3f on duel fuel and manual, would either or both be better on juice than that?
also i have been told the 4litres dont like running gas, chew out valves apparantly, is this true or merely a case of owner negligence? as in not regularly runnin a tank of petrol through it or runnin a moreys or similar system.

thanks for any help!

Posted: Mon Jul 20, 2009 6:24 pm
by joeblow
don't go near the 4.0 litre.....trust me. the 4.5 is a fantastic engine.

4.5

Posted: Mon Jul 20, 2009 7:51 pm
by tiny80
4l slow no power heavy on pocket no beter than ya 60
4.5 great motor heads get rebuilt every 150-200000km
great on power can make up to 500kw on stock internals
fuel better than 4l only just

Posted: Mon Jul 20, 2009 10:46 pm
by crankycruiser
dont touch the 4lt with a barge pole! besides the fact they are gutless, it will also have smaller brakes and a few other minor changes that they upgraded for the 4.5...

the 4.5 is near unkillable... fair bit of power stock and will last near forever, tiny mentioned them doing heads.. but i cant say i have heard of one crapping a head, so may not be overly common? correct me if im wrong!?

Posted: Tue Jul 21, 2009 9:11 pm
by CRAZY80
crankycruiser wrote:dont touch the 4lt with a barge pole! besides the fact they are gutless, it will also have smaller brakes and a few other minor changes that they upgraded for the 4.5...

the 4.5 is near unkillable... fair bit of power stock and will last near forever, tiny mentioned them doing heads.. but i cant say i have heard of one crapping a head, so may not be overly common? correct me if im wrong!?
The cruiser has done 350,000 or somethin like that and hasnt done anything like doing a head.

just my bit.

Posted: Tue Jul 21, 2009 10:18 pm
by TheBigBoy
I havnt heard of them doing heads either. I've had a 4.5 before and it was unkillable forsure. And just got another 1 just to make sure my old 1 wasnt a flukie engine, in the form of a 94 80 series, auto etc.. Just what your looking at. Dunked it over the bonnet on saturday night. No drama's at all.

If you want more power and better eco. Change it to gas injection and run an aftermarket computer with a maffless tune. Can run it leaner and way more k's without any damage.

Ive just got gas injection on mine. And have done 1000 k's. Now have to take it back for retune. 95 litres usable. 400k's for $40. And will get better with retune. More power on gas aswell. Now time for aftermarket comp.

Posted: Wed Jul 22, 2009 8:43 am
by glennyboy
CRAZY80 wrote:
The cruiser has done 350,000 or somethin like that and hasnt done anything like doing a head.

just my bit.
Agree with CRAZY80 - mine has done over 330,000 and still goes hard. No weird engine noises and still has heaps of power. Would recommend this engine to anyone - remember it has a 24 valve twin cam engine to.

Posted: Wed Jul 22, 2009 9:09 am
by crazy eyes
the 4.5 is the way to go they go like a train stock but yes they do have a prblem with the head as i have had 4 of these motors in 80s and 75s all autos and have had to rebuild the head on all of them . they dont die becouse of the head they just start chewing fuel and alittle less power . i race a 75 petrol auto witch i built about 5 years ago it is turboed putting out about 300+hp with a haltech computer and it just keeps going.
but they wear out the valve seats when they are on gas i know this as a mate has been threw all off this about 2 months ago . we rebuilt the head and away it goes we use it as our tow car for the race truck.
cheers crazy eyes

Posted: Wed Jul 22, 2009 7:03 pm
by woodbutcher
Running gas on the 4.5 the valves will actually get tighter and need adjusting on a regular basis

Posted: Thu Jul 23, 2009 8:49 am
by TheBigBoy
I spoke with my gas specialist. He has had a 4.5 on gas for 6 years without any drama's. He said they arent the olden day leaded fuel valves. They are hardened unleaded ones. And if a head goes (loss of power, bad eco etc) he said thats just life. Not to do with the gas.

Posted: Thu Jul 23, 2009 9:19 am
by micntor
We have a 1995 8o with the 4.5l. It pulls hard stock. A set of extractors and a decent exhaust would be great. I used to have a 60 series with the 3f (carby) The 80 goes almost twice as far, twice as fast!

Posted: Thu Jul 23, 2009 1:32 pm
by tiler0172
it isnt the valves that wear out it is the valve seats and it is from the gas .
gas is for bbqs not cars unless it is in a blue bottle with nos stamped on the side lol
cheers

Posted: Thu Jul 23, 2009 1:44 pm
by paulm958
yep agree with most, great engine the 4.5 definatly by far the better choice, but the issues with the heads is mostly due to prolonged running on gas, no gas and very little head issues,
most 4.5s on gas will definatly have a shorter life span, manly due to the valves pulling and tightening up as mentioned in earlier post caused from dryer fuel less lubrication and higher cylinder tempritures, but if the shims are done on a regular basis, over 400k is easilly achievable on duel fuel,
But if they havnt been done for a while and the car has been doing a lot of towing and not getting run on petrol theres a good chance they could be on there way out,
have a good listen to the engine if its running rough at idle and fluttering at the exhaust, may pay to walk away

Posted: Tue Aug 11, 2009 12:05 pm
by MAD80
if you look hard enough for will find a bargain, i picked up my 93 gxl 4.5lt for $6750 the previouse owner had a burnt out valve seat repared at 260k i bought it at 270k and addad an upper cylinder lubricator kit, n have had no trobles since now has 310k+