railstaff:
Good question,simple answer I don’t know.I gather it depends on how fast the water can enter the inlet of the pump.One thing with a ■■■■■■■ liner is its only cooled half way down its lenth,855 is a considerable bit more.
One problem I can see with machining the parent bore away is the deck would become detatched,wet liner blocks still have an internal wall between the cylinders,a bit like a box.To achieve this a longer block would be needed as by the looks of it the new counter bore would be very close to the block studs,but still a good idea with merit.
I can see that being a problem. At least some of the head/block stud holes in the wet liner 690 engine break through into the water jacket. This obviously causes problems with corrosion to the threads and studs shearing. Unlike the 760 and V8 the wet liner engines have 1/2" head studs. It is very common to find that the block has been drilled and tapped for an oversize stepped stud. On the engines I see either there has been considerable damage or since they have been overhauled several times in their lives, it is common to find that the block has been re threaded 5/8" where necessary. Since the V8 starts off at 9/16" to allow for block recovery there would need to be sufficient material to retap to 3/4". However IIRC the TL12 engine block was tapped 5/8" ex factory.
To this day the architecture of the the 690 could still be found in Dafs XEC engine as this also had head bolts that located in open tapped holes in the block.This suffered with cracking of the head casting around the bolt hole relieving coolant out the crack as the coolant made its way up the thread of the bolt.
Tell me about it! The XE engine certainly suffered as a result of the head bolt holes reaching the coolant. That would be the final engine to be developed from BL archtecture.
Basically 1160 block except with an 12.6 litre capacity.Some external differences of course.Dry linered.Two cylinder heads,4 valve per cylinder.Cam in bottom.Waste gated turbocharger on the higher horse power versions.UPEC fuel system,which was basically an extra housing fitted instead of the fuel pump driven direct of the timing gears.Internally it contained a camshaft and 6 pistons which actuated 6 unit pumps controlled by solinoids.Injectors are basic pencil type.
The bolt holes in the block were left open and ventured into the water jacket of the block.When the heads were made the material on the rear of the heads was thin around the rear two bolt holes.In service they developed cracks running down,top to bottom.Coolant leaked out of the cracks because as before the bolt head sealed the hole but now it was open to atmosphere.In fairness to Daf they replaced heads FOC.Later in its life Daf released headbolts with blue sealant bonded to the threaded part of the bolt.
The open-bottomed holes would better permit swarf to escape during drilling and tapping. IIRC, production machine shops much prefer them. I once put a bid in (unsuccessfully!) for the job of designing and making a dedicated high-volume drilling/tapping centre, and asked someone who was good at it for advice. His attention to detail with regard to swarf removal was the key to it. If the holes are blind, you use a helical tap (with some means of stopping it accurately. I forget how it was timed), and do the job upside down if possible. If the hole is through, the job makes a much easier wage.
The great, great, great, great, times however many, grandson of the 1946 Leyland O.600, Leyland Motor’s first monoblock diesel, which was the engine aganst which the AEC had to compete and saw theirby then rather antiquated A 204 series engines superseded by the monoblock wet liner AV590 and AV 690 around about 1950. Thick wall bearings still.
[zb]
anorak:
The open-bottomed holes would better permit swarf to escape during drilling and tapping. IIRC, production machine shops much prefer them. I once put a bid in (unsuccessfully!) for the job of designing and making a dedicated high-volume drilling/tapping centre, and asked someone who was good at it for advice. His attention to detail with regard to swarf removal was the key to it. If the holes are blind, you use a helical tap (with some means of stopping it accurately. I forget how it was timed), and do the job upside down if possible. If the hole is through, the job makes a much easier wage.
When the V8 was modified in the early `70s what happened to the engines , I read on here that they were taken to Leyland but were they scrapped or saved?
ramone:
When the V8 was modified in the early `70s what happened to the engines , I read on here that they were taken to Leyland but were they scrapped or saved?
Were they just on the drawing board or were any running engines actually built with the new block, crankshaft etc?
‘gingerfold’ may know.
I have certainly never seen one, either in a photograph or an actual engine.
I have never even seen a test account of one.
It would have required a substantial investment to actually produce even a single running test engine, and with the financial constraints imposed on AEC by then (which is the very reason the original V8 engine project failed), I think it’s highly unlikely - I may be wrong!.
ramone:
When the V8 was modified in the early `70s what happened to the engines , I read on here that they were taken to Leyland but were they scrapped or saved?
Were they just on the drawing board or were any running engines actually built with the new block, crankshaft etc?
‘gingerfold’ may know.
I have certainly never seen one, either in a photograph or an actual engine.
I have never even seen a test account of one.
It would have required a substantial investment to actually produce even a single running test engine, and with the financial constraints imposed on AEC by then (which is the very reason the original V8 engine project failed), I think it’s highly unlikely - I may be wrong!.
It may be me that`s got it wrong , i thought i had read about Leyland taking a V8 back to Lancashire never to be seen again after the problems had been ironed out
ramone:
It may be me that`s got it wrong , i thought i had read about Leyland taking a V8 back to Lancashire never to be seen again after the problems had been ironed out
I heard that they confiscated the 3VTG concept vehicles, and the 6x4 had a development turbocharged AV810 engine, but that was based on the original AV801 design.
If any new design V8 engines were built, I’m sure ‘gingerfold’ will know.
ramone:
It may be me that`s got it wrong , i thought i had read about Leyland taking a V8 back to Lancashire never to be seen again after the problems had been ironed out
I heard that they confiscated the 3VTG concept vehicles, and the 6x4 had a development turbocharged AV810 engine, but that was based on the original AV801 design.
If any new design V8 engines were built, I’m sure ‘gingerfold’ will know.
No, none of the new proposed engines were built because funding was not available for the new tooling required. Any remaining V8-800 naturally aspirated engines after the project was terminated were used as industrial engines. The turbo-charged AV810 development engines were sent to Leyland and the 3VTG 6x4 unit was used for testing the TL12 engine.
ramone:
It may be me that`s got it wrong , i thought i had read about Leyland taking a V8 back to Lancashire never to be seen again after the problems had been ironed out
I heard that they confiscated the 3VTG concept vehicles, and the 6x4 had a development turbocharged AV810 engine, but that was based on the original AV801 design.
If any new design V8 engines were built, I’m sure ‘gingerfold’ will know.
No, none of the new proposed engines were built because funding was not available for the new tooling required. Any remaining V8-800 naturally aspirated engines after the project was terminated were used as industrial engines. The turbo-charged AV810 development engines were sent to Leyland and the 3VTG 6x4 unit was used for testing the TL12 engine.
Would you post the road test reports on the Av810 engines please? If I have missed them in the fog, tell me to shut up:-).
The turbo-charged V8 was fitted into the 3VTG 6x4 concept vehicle and because of its power output it was mated to the Eaton Fuller range change box type that was used in the manual version of the AVT1100 Dumptruk. (Some Dumptruks had torque convertors, but IIRC the manual AVT1100 Dumptruk had the 9-speed) Its rear axle ratio gave it 64 - 65 mph and it had M4 and M5 dispensation to run at 44 tons gvw. It did the usual 380 miles nightly up and down the M4 as far as Aust services. Coming back from Aust and up the long drag at the M4 and M5 interchange then it was down to about 17mph, but even at 44 tons gross and it would still overtake everything else climbing the hill. The AEC drivers would take a break at Leigh Delamere services and they were frequently approached by other drivers wanting to know “what the hell was in that white Yankee job they were driving?” These other lorry drivers took some convincing that the “Yankee job” was actually loaded to 31.5 tons on the trailer. At the time Marks and Spencer had just put some new Guy Big J tractor units into service with AEC AV505 engines. They pulled single axle trailers running at 22 tons gvw. The M&S drivers also took a break at Leigh Delamere so the game was for the Guys to leave about 5 minutes before the 3VTG then the 3VTG had to catch them and overtake them. The Guys were also good for 65 mph on the level, but at the first hint of a slope the 3VTG got past them, but it was running at twice the gvw of the Big Js. The 3VTG drivers also established a good relationship with the Motorway police patrols who were very interested in what AEC were testing. At that stage of its testing the V8T-810 wasn’t brilliant on fuel, averaging about 5mpg at 44 tons gvw.
ramone:
It may be me that`s got it wrong , i thought i had read about Leyland taking a V8 back to Lancashire never to be seen again after the problems had been ironed out
I heard that they confiscated the 3VTG concept vehicles, and the 6x4 had a development turbocharged AV810 engine, but that was based on the original AV801 design.
If any new design V8 engines were built, I’m sure ‘gingerfold’ will know.
No, none of the new proposed engines were built because funding was not available for the new tooling required. Any remaining V8-800 naturally aspirated engines after the project was terminated were used as industrial engines. The turbo-charged AV810 development engines were sent to Leyland and the 3VTG 6x4 unit was used for testing the TL12 engine.
Did Leyland put a stop to the Turbo AV505 or was that an AEC decision?
There was such a lot of confusion at the time it’s impossible to say who was responsible. The last Mercurys and Marshals were powered by the AV506 engine, which was a naturally aspirated version of the turbo-charged AVT505 that never actually existed in any normal production Mercury or Marshal. Confusing or what? When I checked the build data less than 1,000 AV506 engines were produced. Leyland had wanted to stop production of the Mercury and Marshal ranges in favour of the Lynx and Bison in about 1975, but customer demand for AECs meant that the last Mercurys and Marshals weren’t produced until 1977.
gingerfold:
There was such a lot of confusion at the time it’s impossible to say who was responsible. The last Mercurys and Marshals were powered by the AV506 engine, which was a naturally aspirated version of the turbo-charged AVT505 that never actually existed in any normal production Mercury or Marshal. Confusing or what? When I checked the build data less than 1,000 AV506 engines were produced. Leyland had wanted to stop production of the Mercury and Marshal ranges in favour of the Lynx and Bison in about 1975, but customer demand for AECs meant that the last Mercurys and Marshals weren’t produced until 1977.
Another non logical decision by Leyland i would guess. It goes to show no matter how much they tried to dress the Leylands up with their updated cabs the customer could see through them and voted with their feet
gingerfold:
There was such a lot of confusion at the time it’s impossible to say who was responsible. The last Mercurys and Marshals were powered by the AV506 engine, which was a naturally aspirated version of the turbo-charged AVT505 that never actually existed in any normal production Mercury or Marshal. Confusing or what? When I checked the build data less than 1,000 AV506 engines were produced. Leyland had wanted to stop production of the Mercury and Marshal ranges in favour of the Lynx and Bison in about 1975, but customer demand for AECs meant that the last Mercurys and Marshals weren’t produced until 1977.
Another non logical decision by Leyland i would guess. It goes to show no matter how much they tried to dress the Leylands up with their updated cabs the customer could see through them and voted with their feet
gingerfold:
…At that stage of its testing the V8T-810 wasn’t brilliant on fuel, averaging about 5mpg at 44 tons gvw.
5mpg isn’t too bad, considering the weight, and the fact that they were racing the other lorries. The engines might have been at maximum revs for the duration of those tussles with the Guys. Those early Tru k magazine Eurotests, at 38 tonnes, gave similar fuel consumption.
ramone:
…It goes to show no matter how much they tried to dress the Leylands up with their updated cabs the customer could see through them and voted with their feet
Something I’ve often wondered is why AEC were supplied with the basic Ergomatic cab by Joseph Sankey Ltd for general home market vehicle production, when Leyland were supplied with the deluxe version, and that was (generally) fitted as standard across their respective range.
The basic cab was single skinned at the rear and is therefore slightly lighter, and had less equipment (no opening fresh air vents etc), but why were Leyland’s equipped with the better spec cab?.
The special AEC Mandator V8 cab was a based on the deluxe version, and indeed AEC did fit the deluxe cab for some export markets, but was the decision to supply home market AEC customers with a basic cab taken at Southall or Leyland, I wonder?.