V8 later crank driven oil pump ?

[smallfry]

I have ALL the parts needed, so thats not a problem, but is it worth converting an older V8 to the later crank driven oil pump ? (intermediate type WITH distributor)

Is there any benefit to it ? Or indeed the whole conversion to the serpentine belt arrangement ?

I do like the idea of less load on the distributor gear !

If so, I have read that the rotors can break, but could this be caused/agravated by using 20/50 oil, when i guess the later engines should be run on thinner grades ?

Or is it a complete waste of time ?

[robertspark]

all the books I have read advocate crank driven oil pump.

less load on the timing chain + less wear on the distributor drive gear

the LS engine uses a crank driven oil pump.

If I had the parts I'd do it with EDIS

[Ash.Witty]

Depends on what stage your engine is in eg. In vehicle or rebuild.

I prefer the later crank driven pump but the earlier one works a treat anyway.

Also needs a late serpentine crankshaft if you were thinking of doing it, as they have a longer nose to allow for the width of the gear between the pulley and timing gear.

[Team Idris]

It's a totally fair question, but if it isn't giving trouble I wouldn't. The engine has big bearings designed to run with low oil pressure, so it is happy with an awful pump.

It seems most of the problems are caused by metal flakes from the cam breaking up. The G-rotor pump would hate these.

I had the same thoughts, as I don't like the gear pump and its relief valve, so I went dry sump. This sorts the blue smoke out when off-roading as well.

[Hybrid_From_Hell]

Be very aware swapping bits about on V8s like Timing Covers and bits bobs can be the stuff of nuightmares as sometimes things VVVVVV Nearly - but don't fit, and then

theres also the A needs B needs C = Argh ...like serp front end often have differing camshaft ends, retainers etc, mixing and matching can be "Fun" with a capital "F"

[robertspark]

as Nige says .... unless you have all the bits, or a good stock of bits to mix & match ... you run the risk of being nickel and dimed to death to coin a well known US expression (and you need to weigh it up against your potential gains... I don't think it will give you any more longevity / horsepower / torque for a time and capital investment (last I checked a few years back now, I think the running cost on a crank given timing cover was around the £200 - £220 mark, and they are non-servicable as far as I recollect).... it's normally other things that go on rovers and not directly choice of oil pump related .... rotor arm (if you have one), liners (94mm bore blocks), lifters, camshaft bearings (over time) [didn't think they were DIY replacement - i.e. PIA to do], + obvious poor fueling (tuning) items.

my experience ... 1) get rid of the rotor arm.... therefore distributor, then 2) go plug and play (fully) tunable (megasquirt or other) ... then its down to the top hat debate, presuming somewhere you gassed it or are happy with the current fuel costs ... oil pump changes are due to fast cornering or serious incline (dry sump or baffles), neither one solved by either cam / crank driven oil pump.

[zim]

I changed engine from a dizzy driven to a crank driven.

A much better system i've found. I don't have the space to go dry sump (despite having a dry sump setup sat on the shelf!), but the crank driven doesn't require priming, so once suction is lost it's easy to regain.

HOWEVER - i very much doubt you'll be doing what we're doing (dangling vertically on a string), so i think the dizzy driven style is fine to save all the added hassle as stated above.

G

[smallfry]

Sorry guys, I should have expanded on this a bit first................

I am NOT doing this to try and gain power or torque. I have three engines in bits on the floor ATM so its not any hassle really. I am making a stopgap engine to keep the vehicle on the road while I sort out the engineering for an engine swap I am doing.

I am building it all into a 3.5 and the whole point of the exercise is NOT to spend any money it. Apart from some gaskets, but I want to keep the engine afterwards, so would like the best combination of parts.

As much as would like Megasquirt, I just dont have the money for it, so I am going to run it on the old AFM (Flapper) Efi which IMO is superior to the Hotwire system which I am also junking because it costs too much to do anything with it.

One thing I have noticed though, is that the rocker shafts on the later engines have negligable wear. Certainly no steps worn into the shafts by the rockers, even at high milage. Wobder if this is coincidence, or due to better oil pressure ?

[robertspark]

3.5 is a good engine (no liner issues as you will well know).

With regards to the rocker shafts + wear .... are the rocker arms on the different engines of the same material ..... I thought (from memory and I'm regularly wrong) .... that some engines had steel rocker arms and some ally... (although I think there are some steel aftermarket Fedral Mogul ?? (spelling) steel ones that can be fitted. hence the wear on the rockers tends to be hidden and actually is on the end of the rocker where the ball from the pushrod sits and it forces its way upwards over time .... hence some people fitting steel ones to eliminate this issue. I think it can masquerade as tappet rattle, but everyone seems to recommend shimming the lifters, or using adjustable pushrods and then theres the Rhoads (spelling??) anti-pump / bleed lifters.

The biggest single problem I had with mine (3.5 su's + LPG) was the rotor arms and it didn't matter who's I used they all started tracking sometimes with stranding consequences hence I kept WD40 + a spare rotor arm to get me out of being stuck as I once was in the middle or nowhere norfolk. I blame a mixture of LPG (resistance to spark or allowing the spark to travel), hot engine (LPG + fuel mixture) albeit mine was WBO2 tuned and sat on 14.7:1 except under deceleration or / decel. where the poppet valve on the butterflies gave a nice decel backfire rumble via tubular manifolds. Hence distributor was always the one thing I wanted to get rid of, just my 2p (tin hat at the ready)

In the depths of major conversion (very long running)

If you've got three sat there + time, then no harm, and it's advocated as a higher volume oil pump arrangement so go for it.

[Bowie69]

Steel rockers are a complete waste of money, don't even think about it.

I would, if you can easily do it, go with crank oil pump as well.

[smallfry]

Steel rockers are a complete waste of money, don't even think about it.

.

I bought a set years ago but never fitted them. They are still in a box here. I thought they were far too heavy, and in any case, I dont think they are actually "steel", which implies a one piece casting/forging, but sintered iron. I tried grinding some casting flash off them, and the sparks were a bit erm.......dull and lazy ? More like when you try to grind cast iron as opposed to proper steel, if you know what I mean ?

[smallfry]

3.5 is a good engine (no liner issues as you will well know).

With regards to the rocker shafts + wear .... are the rocker arms on the different engines of the same material ..... I thought (from memory and I'm regularly wrong) .... that some engines had steel rocker arms and some ally... (although I think there are some steel aftermarket Fedral Mogul ?? (spelling) steel ones that can be fitted. hence the wear on the rockers tends to be hidden and actually is on the end of the rocker where the ball from the pushrod sits and it forces its way upwards over time .... hence some people fitting steel ones to eliminate this issue. I think it can masquerade as tappet rattle, but everyone seems to recommend shimming the lifters, or using adjustable pushrods and then theres the Rhoads (spelling??) anti-pump / bleed lifters.

The biggest single problem I had with mine (3.5 su's + LPG) was the rotor arms and it didn't matter who's I used they all started tracking sometimes with stranding consequences hence I kept WD40 + a spare rotor arm to get me out of being stuck as I once was in the middle or nowhere norfolk. I blame a mixture of LPG (resistance to spark or allowing the spark to travel), hot engine (LPG + fuel mixture) albeit mine was WBO2 tuned and sat on 14.7:1 except under deceleration or / decel. where the poppet valve on the butterflies gave a nice decel backfire rumble via tubular manifolds. Hence distributor was always the one thing I wanted to get rid of, just my 2p (tin hat at the ready)

In the depths of major conversion (very long running)

If you've got three sat there + time, then no harm, and it's advocated as a higher volume oil pump arrangement so go for it.

That is why I have stuck to the 3.5 block. Lord knows I have had enough of them, and have never had one fail.

With regard to the rocker pushrod set wear, it is not something I have had a particular problem with. They DO wear for sure, but I think this a something that happens to every make of pushod engine, but they seem to last for a high and acceptable milage. I imagine it WOULD be a problem with high lift cams and strong valve spring loads though !

I do not think that "steel" rockers were EVER a factory fit ?

I also do not think shimming rocker pedestals is a good thing either, as IMO it upsets proper geometry. Ideally what is needed is a selection of different pushrod lengths, like they used to do in the USA. failing that, a far better solution would be to skim the bottom of the pedestals, or shorten the valve stems. Depending on what way you needed to go of course. Although obviously this is not really a DIY fix !

Distributors really are a nightmare I agree, but mostly its the amplifier playing up. Or the rotor arm. Or everything else !

I really dont trust LPG on the bigger bore engines, as if its set up wrongly it will aggravate any possible liner problems by running too hot, and most people are entirely in the hands of whoever is supplying/fitting it. Hard to do with a distributor too, as it has a completely different ignition requirement I understand.

[Bowie69]

I don't think steel rockers were ever factory fit either.

You can still get adjustable pushrods from Real Steel IIRC, though they are really spendy, and can require you to open up the pushrod tube holes in the heads a little to stop them catching.