TVR/Rover 4.8 or 5.0 short engine
Discussion
For an offroad rally car I am looking for a 4.8L or 5.0L rover V8 engine. As far as I know this is a non-standard upgraded version of the standard 4.6L engine. I already have the upgraded heads which are now mounted on a 3.9L engine. Does anyone know where such a short engine is for sale for a reasonable price? Preferably in Europe.
Another option would be to have the conversion done myself. What is the exact modification done to turn the 4.6 into a 4.8 or 5.0? Is this only increasing the stroke or do they also replace the cylinder liners with a bigger bore?
Best regards,
Erik
Another option would be to have the conversion done myself. What is the exact modification done to turn the 4.6 into a 4.8 or 5.0? Is this only increasing the stroke or do they also replace the cylinder liners with a bigger bore?
Best regards,
Erik
5.0's usually use 96mm liners as well as a stroked crank. 3.9's 4.0 will like to rev a bit more easily. Horses for courses as we say over here. 4.0 and 4.6 engines are a good base imo as they have nice strong parts inside from the factory.
Have you considered a turbo and a low boost engine? Put that onto an ordinary engine and you'll get strong results. That's if the rules allow it.
Have you considered a turbo and a low boost engine? Put that onto an ordinary engine and you'll get strong results. That's if the rules allow it.
Could you please help me to understand what you mean with 4-bolt bottom end? I can find that there is a difference between the normal and cross-bolted engines but what is specifically the difference I cannot find. Of coarse the most important is the compatibility with the cylinder heads and gearbox.
Using a turbo or blower is not an option, both rule-wise and because of the amount of sand and water in the offroad rally. The 3.9 engine we have now is already equipped with John Eales heads and a TVR exhaust. This together with the changes to the injection (reprogrammed 14CUX) we now have 200BHP on the wheels (with the 4x4 drive system), so probably around 250BHP at the crank. This proves to be insufficient, therefore we would like to increase the output power and specifically the low-ed torque (now 340Nm at 4k rpm and 300 at 2.5k)
Using a turbo or blower is not an option, both rule-wise and because of the amount of sand and water in the offroad rally. The 3.9 engine we have now is already equipped with John Eales heads and a TVR exhaust. This together with the changes to the injection (reprogrammed 14CUX) we now have 200BHP on the wheels (with the 4x4 drive system), so probably around 250BHP at the crank. This proves to be insufficient, therefore we would like to increase the output power and specifically the low-ed torque (now 340Nm at 4k rpm and 300 at 2.5k)
Just found one on PH classifieds for you :
http://www.pistonheads.com/classifieds/parts-and-p...
4 bolt bottom end means the the crank is attached by 2 bolts and 2 more bolts bolt from out side of the engine (cross bolt).
It makes to bottom end much more robust.
Another feature you should look for is top hat liners.
http://www.pistonheads.com/classifieds/parts-and-p...
4 bolt bottom end means the the crank is attached by 2 bolts and 2 more bolts bolt from out side of the engine (cross bolt).
It makes to bottom end much more robust.
Another feature you should look for is top hat liners.
I've found some places where they sell the converted short blocks for a 4.8 and 5.0. What I don't get is why the 5.0 is so much more expensive than the 4.8. Both have a bore of 96.0mm where for the 5.0 the stroke is longer. Why does this have to be so much more expensive?
In case of the 4.8, are the crankshaft and conrod standard or are they also custom made? I assume the piston is non-standard in both the 4.8 and 5.0, am I correct?
In case of the 4.8, are the crankshaft and conrod standard or are they also custom made? I assume the piston is non-standard in both the 4.8 and 5.0, am I correct?
The 5.0 will usually have a TVR crank and TVR rods inside combined with shortened cast pistons. The 4.8 can be done with a crankshaft from Real Steel along with a piston swop iirc.
3.5 and 3.9 engines use a small journal 2.300" main bearing diameter. The blocks aren't cross bolted as standard. The 4.0 and 4.6 use a larger main journal crank diameter of 2.500" and the blocks are cross bolted by the factory. The crank, rods and pistons are better and stronger the the parts inside the earlier engines, imo.
Quite a few of the later blocks have been linered to 96mm because of coolant issues or just to increase capacity. Not all later blocks have coolant problems.
3.5 and 3.9 engines use a small journal 2.300" main bearing diameter. The blocks aren't cross bolted as standard. The 4.0 and 4.6 use a larger main journal crank diameter of 2.500" and the blocks are cross bolted by the factory. The crank, rods and pistons are better and stronger the the parts inside the earlier engines, imo.
Quite a few of the later blocks have been linered to 96mm because of coolant issues or just to increase capacity. Not all later blocks have coolant problems.
Are these cranks still available to produce a 5.5 engine?
http://boostperformance.co.uk/rover_v8.html
If tourque is what you need then mine produces 460 foot pound of torque.
http://boostperformance.co.uk/rover_v8.html
If tourque is what you need then mine produces 460 foot pound of torque.
TomcatErik said:
I've found some places where they sell the converted short blocks for a 4.8 and 5.0. What I don't get is why the 5.0 is so much more expensive than the 4.8. Both have a bore of 96.0mm where for the 5.0 the stroke is longer. Why does this have to be so much more expensive?
In case of the 4.8, are the crankshaft and conrod standard or are they also custom made? I assume the piston is non-standard in both the 4.8 and 5.0, am I correct?
Speak to Roland at ACR. He supplies all you need and specialises in off road race V8s. In case of the 4.8, are the crankshaft and conrod standard or are they also custom made? I assume the piston is non-standard in both the 4.8 and 5.0, am I correct?
Yes both the 4.8 and 5.0 come with forged pistons. The 4.8 utilises the standard 4.6 crank and rods whereas the 5.0 uses a proper offset ground crank and chevy I beam rods on floating pins with spring locks. This is the option I am building at the moment.
Boosted LS1 said:
Yes but they're difficult to get machined within a reasonable time frame or at reasonable cost. I sell them as blanks nowadays rather then keep a customer hanging on.
That's one of mine in your engine :-)
Thought so, no complaints there!That's one of mine in your engine :-)
Edited by Boosted LS1 on Wednesday 16th September 12:55
Well, we got a bit further with the engine. It is now being assembled to be put in the car. After the first 300km of break-in we will go for the rolling road again. Hope to see 300bhp at the rear wheels.
The engine specs for the interested readers:
JE developments 5.15L crossbolted V8
Bore 94.5mm
Stroke 91.5mm
Conrods 5.700" centres
Pistons are forged Omega
Compression ratio: 10.0:1
Stage 3 heads (JE developments) fully ported
Inlet valve: 42.8mm
Exhaust valve: 36.2mm
Tvr plenum and trumpets
Tvr exhaust manifold with straight open pipe to the back (no silencers)
The engine specs for the interested readers:
JE developments 5.15L crossbolted V8
Bore 94.5mm
Stroke 91.5mm
Conrods 5.700" centres
Pistons are forged Omega
Compression ratio: 10.0:1
Stage 3 heads (JE developments) fully ported
Inlet valve: 42.8mm
Exhaust valve: 36.2mm
Tvr plenum and trumpets
Tvr exhaust manifold with straight open pipe to the back (no silencers)
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