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Aragorn

V8 Performance Oddness

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You don't want a poppet valve coming off and bouncing around the engine! I think that happened to someone on the 101 forum...

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Best way to solder the poppet valve is with a blowlamp …….. there is too much brass to heat up with a soldering iron ;)

With the blowlamp either use plumbers lead and a little bakers fluid ………. Or use plumbers cored solder.

If you have not gaskets and cant get any (there are lots of generics in the parts p[laces for carbs) …….. then leave the old gasket on and run a small bead of silicon around the flange face before bolting up.

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The old gasket has already been removed after liberal application of a stanley blade, so i'll need to either find some new ones, or make some new ones from card.

I dont have a blowlamp, but i guess i could try and pick one up at the weekend to solder these bits.

I pulled a rocker cover off and attempted to measure the valve lift, but its not really an easy job to do myself. Annoyingly the ratchet wont reach the crank nut on its own, and the shortest 1/2" extension i have is too long and causes the ratchet to hit the crossmember. I managed to squeeze a contraption thru above the crossmember using various extensions and universal joints but it wasnt very stable and the engine (even with all the plugs removed) seemed quite hard to turn over.

I dont have a dial test indicator, so i used my vernier caliper to measure from the head casting to the top of the valve spring. They all measured around 38mm with no lift on them, and the best figures i could get were 33.2mm from cylinders 3 and 5. I dont really know if these are peak lift figures though, as i had to keep climbing under, nudging the engine round a little and climbing out to check, so i could possibly have nudged it right past full lift. If they are peak, then the camshaft must be pretty much lobeless lol!

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I dont have a dial test indicator, so i used my vernier caliper to measure from the head casting to the top of the valve spring. They all measured around 38mm with no lift on them, and the best figures i could get were 33.2mm from cylinders 3 and 5. I dont really know if these are peak lift figures though, as i had to keep climbing under, nudging the engine round a little and climbing out to check, so i could possibly have nudged it right past full lift. If they are peak, then the camshaft must be pretty much lobeless lol!

Was the inside of the rocker cover and rockers black ........... if yes, then you are looking at a badly worn engine. The blackness is caused by years of the head gaskets blowing a little into the valley due to the age old issue of the outer row of head bolts causing the heads to tilt very slightly.

To turn the engine over from the crank I use a 3/4 drive long socket and 3/4 ratchet. ........... It is easier to take the plugs out for the measurements you are doing .............. if 3 & 5 are bad then 7 will be almost non existent. ;)

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Hmm, the underside of the cover itself is black, the pushrods had a coating of black goo on them that scraped off when disturbed.

The rest of the insides looked alright though, golden browny colored?

I did take the plugs out, it was just a bit awkward to get at.

I'll try again tomorrow when the missus is home, and see if i can get any better readings.

I managed to solder up the poppet valve, Gas cooker ring + lots of electrical solder did the job :) Reassembled both carbs and set the throttle stops and jet height to the default settings as per the haynes manual.

I'll see if i can get any better readings off these rockers tomorrow, if not i'll just throw it all back together and see how it runs.

Only problem now is i need to find a gas analyser to set the emissions correctly :/ The manual gives a guide to getting it in the right ballpark, so i'll go with that first anyway.

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You know it amazes me how poor these engines actually are...

Our '96 Audi A4 has a 1.8L Turbocharged Petrol engine producing 150hp (ie many times higher state of tune than this RV8) and its done 192000 miles. The oil pump is now showing signs of wear with oil pressure dropping as low as 8psi at idle on very hot days. Our cars also had a sketchy service history before we got it, likely with services having been missed and cheap oil been used (ie very bad for turbocharged engines). But once its spinning above 1500rpm, the pressure comes up and the motor drives like new, doesnt smoke, doesnt rattle, and its camshafts are filly intact!

I suspect the people that built these RV8's were too busy drinking coffee (or striking) to actually engineer the thing properly, and fix the problems. Surely by 1989 when this truck was built, they'd seen 30 years worth of faults with this engine and should have rectified ALL of them...

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Remember the engine design is 1960's at best and fundamentally unchanged. The world moved on a great deal during the life of the RV8.

Although they're not perfect they are very hard to beat in a Land Rover, good low-down grunt, reliable, very tolerant of wear, cheap parts, very basic, and cheap and plentiful second hand. I've looked round at a lot of alternative ideas for engines and nothing has stood head & shoulders above the rest. There are plenty which make far better power & MPG but couple that with the bottom-end grunt to haul 2 tonnes about and the list drops very sharply. Your Audi project being one of the very few worth considering.

As for the blackness in your engine, try running a tin of Forte engine flush through it (as recommended often by Nige) and seeing what happens, they can gunge up especially if only used for short journeys.

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I generally go with using a 50:50 mix of diesel and cheap (ie £4.99 from asda) engine oil to flush out sludged up engines, might give it a try once i get it all running again.

Usually much cheaper and more effective than paying £5-10 for 500ml of kerosine in a can...

Ye, it is a '60's design, but that doesnt mean you cant improve upon it... Look at the GM LSx motors. Rover did finally pull their finger out with the later serpentine engines and fix the oil pump, then at the same time introduced a whole world of hurt with their liner issues!

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Hi

If you can't solder ring up Burlin fuel systems they will sell you butterflies with no poppet valves no bits to fall off .

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Jon: Managed to solder it up over the gas cooker ring :)

Spending money on this engine is being kept to an absolute minimum, and spending money on the carbs is not happening!

Made up some gaskets from a sheet of card, and i've got a tube of hylomar blue type stuff, so i'll just spread that everywhere and bolt them up :D

As they say round here: "Be reet!"

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You know it amazes me how poor these engines actually are...

I suspect the people that built these RV8's were too busy drinking coffee (or striking) to actually engineer the thing properly, and fix the problems. Surely by 1989 when this truck was built, they'd seen 30 years worth of faults with this engine and should have rectified ALL of them...

Ye, it is a '60's design, but that doesnt mean you cant improve upon it... Look at the GM LSx motors. Rover did finally pull their finger out with the later serpentine engines and fix the oil pump, then at the same time introduced a whole world of hurt with their liner issues!

In defence of rover/bl/land rover this 50's designed engine was from an era when cars rusted out many years before mechanical parts wore out. Add that to the fact that people didn't do high mileages what was the point of engineering an engine to be perfect in a scrapyard?

In a modern car we don't expect 3,000 mile oil changes and annual decokes or even a running in period. Production tolerances and improved materials have changed motoring habits but has always been common to find the rv8 servicing ignored.

As for power output it is poor compared to modern engines, but Ford still make the cologne V6 which has similar characteristics (they fit this to the disco 3 in the states)so there is still a demand for high torque, low power pushrod engines.

The LSx engine was brand new in the late 90's.

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My point with the LSx is its a progression of the "small block chevvy". Instead of continually nailing out the same old junkers, they got down to it and redesigned the motor.

By the 80's it should have been clear to rover that the engine design needed overhauled, but it took until ~1994 before they even uprated the oil pump.

Vauxhall released their new C20XE motor in the 1989 Astra GTE 16v. A fuel injected four cylinder 2L 16v petrol engine making 156hp, and at the same time as thats rolling out of Luton, Rover are wheeling their brand new Discovery out into showrooms with a 8.13:1 CR Carbed V8...

Anyways. I'll try and measure these valves again tomorrow, then get the carbs nailed back on and see how it goes.

I need to work out how the fuel filter goes back together. Anyone got a diagram showing how the bits bolt together?

Cheers

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That, is a restrictor plate, designed to limit the power to around 90BHP for the stage 1 V8, Sherpa vans and some other applications....

Could this be why it is a little gutless :P

More info here: http://www.glencoyne...e1/v8improv.htm

Oh, and here http://www.stage1v8.org.uk/phpBB2/viewtopic.php?t=1177&highlight=restrictor

Might be worth getting the engine number off it, to see where it came from, that is unless the carbs were swapped without the engine....

HTH :lol:

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Engine number is 27G008xxB, which afaik is the original Disco engine, rated at 144hp.

Given that the carbs were dated 1994 and 1995 though, they arent original, so perhaps the manifold/carbs are off something random?

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My point with the LSx is its a progression of the "small block chevvy". Instead of continually nailing out the same old junkers, they got down to it and redesigned the motor.

By the 80's it should have been clear to rover that the engine design needed overhauled, but it took until ~1994 before they even uprated the oil pump.

Vauxhall released their new C20XE motor in the 1989 Astra GTE 16v. A fuel injected four cylinder 2L 16v petrol engine making 156hp, and at the same time as thats rolling out of Luton, Rover are wheeling their brand new Discovery out into showrooms with a 8.13:1 CR Carbed V8...

Anyways. I'll try and measure these valves again tomorrow, then get the carbs nailed back on and see how it goes.

I need to work out how the fuel filter goes back together. Anyone got a diagram showing how the bits bolt together?

Cheers

To be fair, the same old junkers were being exported to the four corners of the globe where 8.13:1 was about right for the dubious quality fuels they were expected to run on. I'd agree, the 70's weren't exactly filled with wonderous achievements at BL. Square steering wheel anyone?

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Engine number is 27G008xxB, which afaik is the original Disco engine, rated at 144hp.

Given that the carbs were dated 1994 and 1995 though, they arent original, so perhaps the manifold/carbs are off something random?

Yep, 27G is an original Disco engine, only thing I can think the carbs/manifold are off is something like a Sherpa or LDV ambulance, put simply, rip them out and off you go.

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Any tips on removing these restrictors?

It seems they just "pull" out... But i just can get enough grip on it.

I tried hammering a chisel and some screwdrivers between the lip to lever it out, but that just resulted in me snapping the edge of the casting.

I thaught i might be able to use a slide hammer technique, but the holes are just larger than M8 stud bar, so i cant cut an M8 thread and M10 would require lots of drilling and therefore swarf everywhere...

My old other thaught would be to use the M8 bar and some araldite and leave it to set for a few hours, but i dont know if that would be strong enough.

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There should be a snap ring in place, can you not get that out with a screw driver?

I wouldn't try a slide hammer technique, I suspect he snap rings will hold them pretty well, and you could end up damaging the manifold...

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it feels a bit like an internal circlip. Theres no obvious retention mechanism from the outside.

The restrictor turns freely, and if you pull on it it moves forward a little then stops.

Araldite didnt work, the bore is too smooth for it to take a grip, its pissing me off now, gonna see if i can drill a hole and tap an M8 thread into the middle of it for the slide hammer, just not sure how i can stop the swarf from getting into the manifold.

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With that date stamped on the carbs I would suspect the manifold is from a Mil 127 ambulance………………. Pull out the snap ring and then pull out the restrictor.

You may also need to change the needle in the carbs ............. IIRC the restricted engines had a different needle.

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Where is this snap ring? i just cant see any way of getting to it, as surely its down the side of the insert...

I think i'm just going to pull the entire inlet off and go mental with the power tools. Getting mighty Mildly miffed off hanging over the edge of the bonnet poking at a crappy piece of aluminium.

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Ok, Got it out by tapping the centre of it out to M10, winding a bolt in and using part of a bearing puller and some spacers to draw it out!

Theres absolutely no way to get to that circlip when the restrictor is fitted.

Pic for reference:

http://www.lr90.org/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=352&g2_serialNumber=2

I guess if i'd been able to get a good grip on it i might have been able to pull it past the locating ring, but it was pretty damn tight coming out of there even with the puller.

As i feared though, theres now i pile of swarf sitting down inside the inlet. I'm going to have some lunch then i'm gonna see if the vacuum cleaner will reach down inside and suck all the carp out. Really cant be arsed taking the inlet off :@

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Well good news is i managed to get all the swarf out of the nearside inlet tract, vacuum cleaner + garden hose = win!

Bad news is doing the same on the other side hasnt worked, because my crappy tap set wouldnt take a grip properly and now theres a massive gaping hole of ripped alloy :(

I think i'm going to need to find a 10mm drill bit, and tap it out to M12. Unfortunately i cant see one in my toolbox so that means lots of raking around.

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Tried smacking it with a hammer?

If not, try harder :P

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