Thread: p76 4.4 v8 in a 1972 range rover, which carby?

Once again you are flying high with hypotheticals. I remind you:

You are doing up a 40 year old long-stroke passenger car engine.

These things are known to break crankshafts if driven enthusiastically.

If you repeatedly exceed 4000rpm you will break it.

A standard WW2 Stromberg carby will allow it to get to 5500 rpm.

If you want a strong engine buy a strong engine.

A p76 engine kept below 3000rpm will last a long time if well maintained.

yes, they break cranks, in fact that is the only engine i have ever seen broken doing 3500rpm conversely the carby 3.5 it replaced in the search for 'mo powa ' regularly saw valve floating revs will no ill effects....


jc

high revs do not interest me, I have my v8 bmw for that which revs to 8k.

More concerned about getting the most out of the cam and compression !

Hi hmmm I have not heard of this crank braking problem before interesting, I have been playing with P76 engines for year's I have 3 at the moment as for carby I like to use a 350 holley very tunable easy for parts. Hopfully will be building up a p76 running only on gas, injection or gas research carby? not sure yet.. Oh also I think Brabham play with P76 engines and Repco built a repco 5000 engine out of the too

Hi guys, i have had a little experience with a 4.4 leyland. I injected one a few years ago ( i still have it now ), use genuine pistons to start with holden flat tops will fit and are cheaper but will give you piston slap with high compression. As for the keeping the revs below 3k i have had mine balanced etc and i still agree with this statement. You will not need to take it higher if you build it right, take 3 to 4 kilos off the flywheel it will help with acceleration you will lose a little torque but you will make that up from the capacity increase of motor.

If i had my time again i would spend the money on a 4.6 or if i wanted to be tight a 3.9. all said and told my engine cost me close 8k by the time i had the hard lesson of the pistons etc that is with the wolf 3d ecu.

Broken Cranks mmmm About the same as a Tdi head gasket hey Jc
No all bull a side Skip the holley for off road they are Shear crap and the stronberg off road unless the holley is one that has all the good bits for off road .
Years ago I just used injection on my 86 hiline with the 4.4 it had Lpg so I had the best of both worlds

well its going in the 72 rangie so I am running a std rangie flywheel as its going on to my re-built lt95 with overdrive. Torque is a good thing offroad as you all know so will probably leave the flywheel alone.

I wont be revving it much, although it is easy to get over 3.5k sometimes when joining our stupidly busy motorways (highways to you blokes)

with the cam and compression I am running I dont want to end up starving the motor of air or fuel as the mixer ring will make the inlet even smaller. I had a vw once which as a teenager I took out on the highway and got up to a silly speed, it wouldnt go anymore not cos the revs were high but the breathing was no enough, as I will be running extractors on this set up I dont want to let the set up down with the std carb if it cant flow enough (even not at silly speeds) what cfm can this motor draw as a maximum? that would give us a parameter to work with I guess?

I agree the ww or a normal holly would be poor offroad which is why by that stage it will run gas when offroad but the other option is the holly truck avenger which is no more expensive than a std holly and is 470 cfm as against 270 cfm with the ww carby but the ww is being rebuilt by a kiwi mate right now and will be posted over which is fairly cheap.

The truck avenger would cost me a bit more but also I am guessing will need another type of inlet manifold? postage on something like that from your side of the world wont be cheap! (spent a hell of a lot already on postage)

I would prefer a single plane inlet with a single mixture and idle adjustment on whichever carby I use, the ww isnt set up that way is it?

Just a quick note after some more re-search, the twin SU hif6 carbys on my current 3.5 provide anywhere between 250 and 300 cfm depending on the source read, so really for an engine that is a liter bigger the WW seems like a small carby at 260/270 cfm? and thats without the mixer ring in there