Hello all,
Newbe alert! I am reading through various posts on this forum and playing catch up.
I'm working on a Land rover based project that will be used off road. It has an autobox and is currently stock, but the engine is in a poor state of health. Compression test readings are 140-150psi (9.35:1 compression ratio) and cam has bad wear apparent.
Currently I'm planning for de-glaze, rings, Cam, cam bearings, timing gears (all metal) and chain, followers, rods, rockers, oil pump, water pump, and gaskets. I'll be inspecting the bearings in the bottom end this weekend coming. Bill of materials so far is getting very close to one of the all in rebuild kits which are around £970.
I would like to run mega squirt and a slightly tweaked cam. Is cross bolting (this block is an interm block, same casting as cross drilled but not drilled) a good idea or not for a 200 ish bhp build? Studs for the heads or are these an unnecessary expense until much more horsepower?
Also most tuning guides are for increasing top end power. Are there good resources for tuning in a way that doesn't reduce low end torque, and modifications that would improve the efficency/economy of the engine?
I've seen acouple of people here have had their 3.9 V8 cross drilled. How much is this likely to cost? Likewise for a basic bit of head work to improve flow? Would the latter necessitate exhaust work too?
On a budget 3.9l Rebuild for 4x4
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Currently reading through these posts:
http://www.v8forum.co.uk/forum/viewtopi ... r&start=15
http://www.v8forum.co.uk/forum/viewtopi ... sc&start=0
http://www.v8forum.co.uk/forum/viewtopi ... 2322e8b774
I've seen one price for tophat liners - £850. I think this was supply and fit. I don't think I need them but understand if people say it just isn't worth rebuilding without doing this.
http://www.v8forum.co.uk/forum/viewtopi ... r&start=15
http://www.v8forum.co.uk/forum/viewtopi ... sc&start=0
http://www.v8forum.co.uk/forum/viewtopi ... 2322e8b774
I've seen one price for tophat liners - £850. I think this was supply and fit. I don't think I need them but understand if people say it just isn't worth rebuilding without doing this.
At the risk of looking like I'm talking to my self I'm not 100% against the idea of transplanting to an LS engine but I'm aware that's not a simple swap. If I were to do that is there ways of bolting it to the standard autobox or bolting a transplanted autobox and engine to the same transfer box?
I'd entertain the henous idea of de tuning the LS until I could affort to upgrate the power train to avoid the need for a calibrated torque limiting right foot!
I'd entertain the henous idea of de tuning the LS until I could affort to upgrate the power train to avoid the need for a calibrated torque limiting right foot!
If you are on a budget then dont go down the LS route as its expensive to get all the adapters etc to work properly, is this going to be a competition vehicle or for pay and play?
If its for the latter then stick to stock as its cheaper and more reliable and when you drown it (which will happen
) you have spent loads of money
If its for the latter then stick to stock as its cheaper and more reliable and when you drown it (which will happen
) you have spent loads of moneyRange Rover 630R or otherwise known as the Money Pit
MS2 with switch MAPS for LPG
Techedge Wideband Sensor
MS2 with switch MAPS for LPG
Techedge Wideband Sensor
Yeah, just read through a big thread on a LS into a Defender. A lot of work in addition to the cost.
So ignoring the LS route is cross bolting with the smaller journal crank worth doing? Likewise studs for the heads and mains?
LS into a defender thread:
http://www.ylrc.co.uk/forum/viewtopic.php?t=194
This involved mods to the chassis, so now you'd need an IVA after doing so.
So ignoring the LS route is cross bolting with the smaller journal crank worth doing? Likewise studs for the heads and mains?
LS into a defender thread:
http://www.ylrc.co.uk/forum/viewtopic.php?t=194
This involved mods to the chassis, so now you'd need an IVA after doing so.
Hi
you are looking at the usual limitations of the rover here, very poor heads. these always limit your options when tuning and tend to drive you towards more cam timing and overlap and revving the engine to extract a few more HP.
I think your best bet would be a 4.2 crank for the 3.9 block, forget the cross bolting not worth it for 200 odd bhp and all the extra machining gains you no power. use a cam like the turbo/blower cam from real steel and with the extra stroke you should get good bottom end pull with a reasonably wide power band but you will need to find decent pistons.
best regards
Mike
you are looking at the usual limitations of the rover here, very poor heads. these always limit your options when tuning and tend to drive you towards more cam timing and overlap and revving the engine to extract a few more HP.
I think your best bet would be a 4.2 crank for the 3.9 block, forget the cross bolting not worth it for 200 odd bhp and all the extra machining gains you no power. use a cam like the turbo/blower cam from real steel and with the extra stroke you should get good bottom end pull with a reasonably wide power band but you will need to find decent pistons.
best regards
Mike
poppet valves rule!
Thanks for the feedback and information, it's been a great help & interesting. This is a slow burn project but it is happening!
So the blower cam reduces overlap which in turn gives better torque at lower rpm? The real steel page recommends the lifters that pump up at around 3000rpm. Would this combo reduce the valve opening too far at the bottom end or is that exactly what I need for a torquey motor?
As for the head work I seem to remember that big valves are mainly for when you want to rev it hard? In my newbe persective big intake area would drop gas velocities and possibly lead to the larger droplets of fuel falling out of the flow? So head work would mainly revolve around reducing flow restrictions?
Like the idea that this leaves the blower route wide open for a later date!
So the blower cam reduces overlap which in turn gives better torque at lower rpm? The real steel page recommends the lifters that pump up at around 3000rpm. Would this combo reduce the valve opening too far at the bottom end or is that exactly what I need for a torquey motor?
As for the head work I seem to remember that big valves are mainly for when you want to rev it hard? In my newbe persective big intake area would drop gas velocities and possibly lead to the larger droplets of fuel falling out of the flow? So head work would mainly revolve around reducing flow restrictions?
Like the idea that this leaves the blower route wide open for a later date!
The 3.9 is 190BHP as I recall, so completely standard parts are a realistic option.
A simple cam upgrade should take you to 200, at the expense of some torque.
I would stick with as many standard parts as possible - you won't need anything fancy.
Chris.
A simple cam upgrade should take you to 200, at the expense of some torque.
I would stick with as many standard parts as possible - you won't need anything fancy.
Chris.
--
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8
Hi
I do not like the lifters that collapse below 300 revs to reduce lift and duration they are noisy when not pumped up, this is invariable when cruising. They are intended to tame far more radical cams than the blower cam and all they will really do is reduce flow in the heads at low RPM. they are intended for rally type applications where you need the engine to run on the road between stages then you can use the full on race cam on the stages.
I would stick with a target of about 200 bhp and beef up the torque curve with the 4.2 crank use su carbs and match the manifold to the heads (not gaskets) stage 1 heads and the blower cam it should be a good 4x4 motor. if not forget the rover and go for a 5.3 LS it will be cheaper in the long run than trying to get more out of the rover.
best regards
Mike
I do not like the lifters that collapse below 300 revs to reduce lift and duration they are noisy when not pumped up, this is invariable when cruising. They are intended to tame far more radical cams than the blower cam and all they will really do is reduce flow in the heads at low RPM. they are intended for rally type applications where you need the engine to run on the road between stages then you can use the full on race cam on the stages.
I would stick with a target of about 200 bhp and beef up the torque curve with the 4.2 crank use su carbs and match the manifold to the heads (not gaskets) stage 1 heads and the blower cam it should be a good 4x4 motor. if not forget the rover and go for a 5.3 LS it will be cheaper in the long run than trying to get more out of the rover.
best regards
Mike
poppet valves rule!
Hi
the easiest way is to dowel the heads to the manifold so they will always return to the same place then look to see which is the largest, manifold or head. Take a piece of cornflakes packet and make a blank gasket, ie cut out the stud holes and dowel holes but leave the port hole blank. Put the blank gasket/cornflakes packet over the gasket face and tap around the ports with a small ball pane hammer to mark the gasket/cornflakes packet. Take it off and using a scalpel cut out the port holes. Now cover the face to be matched with marking out blue and using a scribe mark round the port hole. If the ports are off set to each other so that neither larger on all sides then you have to add a step in that you put it on one face and tap around with the hammer, swap it to the other side and tap around there. Cut out using a knife and mark both faces. From memory there is a good write up of this in the Dave Vizard A series tuning book.
best regards
Mike
the easiest way is to dowel the heads to the manifold so they will always return to the same place then look to see which is the largest, manifold or head. Take a piece of cornflakes packet and make a blank gasket, ie cut out the stud holes and dowel holes but leave the port hole blank. Put the blank gasket/cornflakes packet over the gasket face and tap around the ports with a small ball pane hammer to mark the gasket/cornflakes packet. Take it off and using a scalpel cut out the port holes. Now cover the face to be matched with marking out blue and using a scribe mark round the port hole. If the ports are off set to each other so that neither larger on all sides then you have to add a step in that you put it on one face and tap around with the hammer, swap it to the other side and tap around there. Cut out using a knife and mark both faces. From memory there is a good write up of this in the Dave Vizard A series tuning book.
best regards
Mike
poppet valves rule!
Hi
the easiest way is to dowel the heads to the manifold so they will always return to the same place then look to see which is the largest, manifold or head. Take a piece of cornflakes packet and make a blank gasket, ie cut out the stud holes and dowel holes but leave the port hole blank. Put the blank gasket/cornflakes packet over the gasket face and tap around the ports with a small ball pane hammer to mark the gasket/cornflakes packet. Take it off and using a scalpel cut out the port holes. Now cover the face to be matched with marking out blue and using a scribe mark round the port hole. If the ports are off set to each other so that neither larger on all sides then you have to add a step in that you put it on one face and tap around with the hammer, swap it to the other side and tap around there. Cut out using a knife and mark both faces. From memory there is a good write up of this in the Dave Vizard A series tuning book.
best regards
Mike
the easiest way is to dowel the heads to the manifold so they will always return to the same place then look to see which is the largest, manifold or head. Take a piece of cornflakes packet and make a blank gasket, ie cut out the stud holes and dowel holes but leave the port hole blank. Put the blank gasket/cornflakes packet over the gasket face and tap around the ports with a small ball pane hammer to mark the gasket/cornflakes packet. Take it off and using a scalpel cut out the port holes. Now cover the face to be matched with marking out blue and using a scribe mark round the port hole. If the ports are off set to each other so that neither larger on all sides then you have to add a step in that you put it on one face and tap around with the hammer, swap it to the other side and tap around there. Cut out using a knife and mark both faces. From memory there is a good write up of this in the Dave Vizard A series tuning book.
best regards
Mike
poppet valves rule!
