I am currently rebuilding a Rover V8 3.5 litre engine and I would like to get advice from people with experience rebuilding and developing these engines.
The engine is fitted in a 1986 Land Rover 90.
The intended use is:
- normal road driving
- occasional off-road / trail use
- occasional longer journeys, but not regular long-distance touring
I am not looking for a high RPM race engine.
The objective is a reliable torque-focused engine with good low and mid-range performance, smooth running and good drivability.
Engine details:
- Rover V8 3.5 litre
- Block number: 21G00369
- Original compression ratio: 8.13:1
- Originally fitted with carburettors
- Later converted to Lucas Flapper EFI
- Engine is now completely stripped for a full rebuild
The engine will be rebuilt from the bare block, so I would like to make the correct decisions before buying parts.
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CURRENT BUILD PLAN:
## Bottom end:
- Complete block cleaning
- New core plugs
- Oil gallery cleaning
- Block inspection
- Cylinder measurements before final decision
- New pistons (considering 9.75:1 compression ratio)
- New piston rings
- New main bearings
- New big end bearings
- Crankshaft inspection
- Connecting rod inspection
- Rotating assembly balancing
The cylinders have already had an initial taper and ovality check.
The final decision between standard bore and rebore will be made after professional measurements.
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## Camshaft and valvetrain:
Planned:
- Kent H200 hydraulic camshaft
- New hydraulic lifters
- New timing chain and gears
The priority is:
- low and mid-range torque
- smooth idle
- good throttle response
- reliability
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## Oil system:
The engine uses the early/pre-serpentine Rover V8 front cover oil pump.
Planned:
- Front cover inspection
- Oil pump inspection
- New oil pump gears if required
- Pressure relief valve inspection
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## Cylinder heads:
The cylinder heads will be checked:
- Valve seats
- Valve guides
- Valve seals
- Springs
- Surface condition
- Resurfacing if required
The objective is torque and reliability rather than maximum horsepower.
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## QUESTIONS:
### 1) Compression ratio
For a Rover V8 3.5 used in a Land Rover 90, would you recommend a 9.75:1 compression ratio?
Would 9.35:1 be a better choice for a road/off-road engine where reliability, low speed torque and temperature control are important?
The engine will run on pump fuel.
Is 9.75:1 a good match with the Kent H200 camshaft?
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### 2) Pistons and machining
If the original cylinders are within acceptable limits:
Would you keep standard bore with STD pistons?
At what point would you recommend a rebore?
Would you recommend any particular piston manufacturer for this type of build?
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### 3) Kent H200 camshaft
Is the Kent H200 a good choice for:
- Rover V8 3.5 litre
- 9.75:1 compression ratio
- Lucas Flapper EFI
- Land Rover road/off-road use?
Would another camshaft profile be better suited for a torque-focused engine?
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### 4) Cam timing and valve train
Would you recommend:
- standard timing gears?
- duplex chain?
- adjustable timing set?
Should the cam timing be checked and corrected during assembly?
What hydraulic lifter preload should be targeted with the H200 camshaft?
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### 5) Balancing
Would you recommend full rotating assembly balancing?
Including:
- crankshaft
- pistons
- connecting rods
- flywheel
- harmonic damper
Is this worthwhile for a 3.5 litre road/off-road engine?
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### 6) Fasteners
Would you replace:
- big end bolts?
- main bearing bolts?
Are ARP fasteners useful for this specification, or unnecessary?
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### 7) Oil pump
For the early/pre-serpentine front cover oil pump:
Are new gears normally sufficient?
Should the complete front cover be replaced if wear is found?
Are there specific measurements that should always be checked?
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###
Lucas Flapper EFIThe engine currently uses Lucas Flapper EFI.
Would you keep the Flapper system with this specification?
Would upgrading to Hotwire 14CUX provide a noticeable improvement in:
- torque?
- drivability?
- reliability?
Reliability and smooth operation are more important than maximum power.
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### 9) Exhaust system
I also have a Range Rover 3.9 exhaust system:
- HRC1583 manifolds
- HRC1584 manifolds
- Y pipe with lambda sensor bosses
- NTC1484 centre silencer
Would this be a worthwhile upgrade for a 3.5 litre Rover V8?
Would it improve torque and drivability, or would the original system be better suited?
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## FINAL OBJECTIVE:
The aim is to build a strong and reliable Rover V8 3.5 litre engine for a Land Rover 90, suitable for road use and occasional off-road driving.
Current planned specification:
- Rover V8 3.5 litre
- 9.75:1 compression pistons
- Kent H200 camshaft
- New hydraulic lifters
- New timing set
- Balanced rotating assembly
- Refurbished cylinder heads
- Lucas Flapper EFI initially
- Range Rover 3.9 exhaust system
I would appreciate advice from anyone who has built or used similar Rover V8 engines.
Any recommendations, experience feedback, or things to avoid would be greatly appreciated.
Thank you.
