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Alloy v8
Posted: Sat Jul 21, 2012 5:44 pm
by Batfastard
Well im building a rr chassis defender cab whinch truck.maybe one day when i understand how to post some pics ,i will.its been a real mind fark deciding what to power it with.My brain is telling me to use a lexus or a ls1.but my heart is saying it must be rover/british based......but its very hard/expencive to extract 240 to 300hp out of the old 3.5 or 3.9.
But as luck would have it im in the middle of another rover project.one of the donner r/r that i thought had a 3.5 in it .turns out to have a 4.4 p76 motor in it.
So that has now been stripped down and cleaned up and is off to wayne at northshore engine rebuilders,get the crank ground .rebored and new pistons.heads will go and be made to breath better.
It will run a fourbarrel holley,on lpg,as i hate computers as i cant under stand the or fix them.the lpg will stop the fuel starvation that you can get with petrol.hopeing for 310 to 340hp.hope im not pulling myself with a big hand,or wasteing my money
Ive looked on line to find some info on what pistons to use to up the compresion.but alot of the info is s econd and third hand.
Holden 173 and 202
Falcon
Mitsi
Is there anyone on here that can give me some first hand info or put me in touch with some one who can.
Re: Alloy v8
Posted: Sun Jul 22, 2012 7:31 pm
by Big
Using lpg might have its own problems.. Lines will freeze and when giving it the fat.. Ask B Perry in Diddimo ( w/e tis a pootral) but he had no end of trouble with gas.. Kept saying chuck it and EFI it and it'll be a beast.. now its sitting somewhere rotting for all i care..
But if you can get over the tuning and freezing things then it'll be a beast..
Re: Alloy v8
Posted: Mon Jul 23, 2012 9:20 am
by tow99
why not run a megasquirt or link type computer and have a simple setup aswell as a setup that is easily tunable?
Re: Alloy v8
Posted: Mon Jul 23, 2012 1:02 pm
by Crash bandicoot
tow99 wrote:why not run a megasquirt or link type computer and have a simple setup aswell as a setup that is easily tunable?
starting to get into LS1 price territory with aftermarket computers etc
Re: Alloy v8
Posted: Mon Jul 23, 2012 7:48 pm
by Batfastard
tow99 wrote:why not run a megasquirt or link type computer and have a simple setup aswell as a setup that is easily tunable?
Good question tow99
For the cost of a mega or link setup with setting the p76 with injection.my 300 hp p76 motor will be built and payed for.
Lpg has a much higher octane then petrol.
No water or shit in the petrol tank.
When i roll it im not covered in petrol
With a rock gas card its only $1.05 p/l
Wil have a main lpg tank 120l and have a pipe tee ins so i can hook a forklift bottle if needed.could then borrow 4x fork lift bottles .so then could do a trip like the godley no probs on lpg.will look at a smaller petrol tank as well. I could run 98 petrol and a octane bosting agent and not have to mess around with the timeing.
Also i can fix a four barrel holley or lpg setup on the side of the road.not sure i could fix a computa or injection the same way
Re: Alloy v8
Posted: Mon Jul 23, 2012 9:22 pm
by tow99
Sounds like your minds made up. I like the idea of the bottles. Makes for a simple setup and easily removed if you have to cut or weld on the vehicle.
Re: Alloy v8
Posted: Mon Aug 20, 2012 11:00 pm
by oldyella
Think the chart below is based on a stage 1 cam so pretty usable grunt
4.6l fully worked = 310Hp
340hp maybe with a stage 2 cam
I'v only got the 3.9l so am going to be aiming around 235hp to 275hp area when I rebuild
Re: Alloy v8
Posted: Mon Aug 20, 2012 11:48 pm
by Batfastard
The problem we have is we can get well in excess of 400 plus hp out of a 3.9 or a p76 motor but it will be totaly unuseble in a4x4 situation.we would rev to 8000 and would not get onto the cam till around 3900 to 4200 rpm.
Droped my heads off to marsh motorsport,they have a long history with rover / p76 .2k for port polish big stainless valves and to match up intake manifold.all work done with the help of his very upbeat flow bench. Was very pleased with that price.
Ive found a supercharger with belts pulleys and manifold to fit the p76 but its been a hard job getting this man to part with it.but there is still hope.
The benift of the supercharger are huge as we will be able to run a heaps more aggresive cam,giving a big boost to the total hp output.
Re: Alloy v8
Posted: Tue Aug 21, 2012 4:31 pm
by oldyella
Batfastard wrote:Ive found a supercharger with belts pulleys and manifold to fit the p76 but its been a hard job getting this man to part with it.but there is still hope.
The benift of the supercharger are huge as we will be able to run a heaps more aggresive cam,giving a big boost to the total hp output.
What is the make and model of the supercharger?
Re: Alloy v8
Posted: Tue Aug 21, 2012 4:45 pm
by Petemcc
From memory the main problem with the old p76 engines is the cranks cracking. A mate of mine had one in his jet boat, was running ok but using heaps of oil so he sent it in for a rebuild but was told the crank was cracked. went found two more doners that had similar problems before finding a good one. Was talking to another guy who used to have a marathon boat running a very worked p76 and he said they imported a whole pallet of 2nd hand cranks to get some good ones to replace the ones they were busting and a large proportion of them were cracked too.
Either way might be something to look out for and possibly investigate stronger options?
Cheers,
Pete
Re: Alloy v8
Posted: Tue Aug 21, 2012 5:06 pm
by Sadam_Husain
Batfastard wrote:My brain is telling me to use a lexus or a ls1.but my heart is saying it must be rover/british based......but its very hard/expencive to extract 240 to 300hp out of the old 3.5 or 3.9.
its pretty hard to beat the cost of a late model engine thats already got all the horsepower and performance you want verses trying to rebuild and ring the necks out of 30-40+ year old worn out old motors which will probably end up costing more in the long run and wont have the same reliability or performance of an LS
http://www.trademe.co.nz/motors/car-par ... 682933.htm$1800
http://www.trademe.co.nz/motors/car-par ... 685731.htm$2600
http://www.trademe.co.nz/motors/car-par ... 950148.htm$3000
http://www.trademe.co.nz/motors/car-par ... 319676.htm$3500
http://www.trademe.co.nz/motors/car-par ... 493319.htm$4384
Re: Alloy v8
Posted: Tue Aug 21, 2012 5:26 pm
by petefj40
^^^^^^^^
What he said.
Not being able to put a spanner to a computer, I can understand. And yeah, you can do a lot with a spanner and a screw driver to a failed carby on the track.
But I used run a Lexus V8 in my buggy for a couple of seasons. I never had issues with the injection. Just water getting into the dizzies. The LS1 I had in my FJ40 (once wired up correctly) I could run fully submerged (till the alternator failed) .
But it sounds like you've already made up your mind on which alloy V8 to go with.
Re: Alloy v8
Posted: Tue Aug 21, 2012 7:14 pm
by Batfastard
Re: Alloy v8
Posted: Tue Aug 21, 2012 7:36 pm
by Batfastard
petefj40 wrote:^^^^^^^^
What he said.
Not being able to put a spanner to a computer, I can understand. And yeah, you can do a lot with a spanner and a screw driver to a failed carby on the track.
But I used run a Lexus V8 in my buggy for a couple of seasons. I never had issues with the injection. Just water getting into the dizzies. The LS1 I had in my FJ40 (once wired up correctly) I could run fully submerged (till the alternator failed) .
But it sounds like you've already made up your mind on which alloy V8 to go with.
Pete im commited to build this p76,heads getting mod,block getting worked on.but i may not make it into my winch truck.only time will tell.i feel it would slip nicely into my 75 rr convertible, if it becomes surplus to requirements
Im not one. Whom asks for advice and dose not listen, ive spent much time planing this build.a wise man on this site said in the thread i started re range rove or disco said you should buy that blue rangie winch truck on trademe,as its got most of the hard work and money spend on it.thought long and hard on that one .if you look on trademe its now sold.maybe it will soon find it self parked in my workshop.
But as they say on ore if theres no pics its not true.....
But if i was a betting man ,i would bet on a ls1 rather than a lexus.....
Re: Alloy v8
Posted: Tue Aug 21, 2012 7:37 pm
by Jerry
Re: Alloy v8
Posted: Tue Aug 21, 2012 7:49 pm
by Batfastard
Bring on da chubby chicks,by the bus load!
