Part 2:
Now a Bunch of guys will come on and leave messages about a 4.6 engine that makes huge horse power and has been completely reliable.. Yes and they get built to crazy levels and Guys road race them in Triumph TR8S.. But those vehicles are so light that the throttle is rarely wide open for more that a few seconds at a time and the cooling system has ample time to absorbe heat.. Put a camper behind it and head up hill in the mountains where the throttle is nearly wide open for 15 minuets to half an hour at a time, and the results are not the same..
Hahaha, well I have knowledge because so many of them fail, I did my first one because my accountant owned it and he was almost desperate to trade out services..(LOL)...NO Kidding, 2 years later I was getting them from all over...I will try not to bore you to much, But if you want long term durability you need to stay with a 4.0 so that you get away from the hot spot sleeve issue, So you are going to want a long nose 4.0 crank and rods, ( Rotational assembly), You need to keep the fire deck above the water jacket.. Whether you use a 4.0 or 4.6 block would have to be determined by the actual block that you are looking at.. Don't commit to any block before you have removed the sleeves and had the block hot tanked, After hot tank have a really close look for cracks on the inside of the counterbores especially the rearmost ones, If that's a Pass then Pressure test, then check for line bore both on the crank and cam bosses; if it's a pass on that then have the machine shop hit the cylinder counterbores with a sunnet hone Just enough to get the Oxidation off for a good set of measurements Keep good notes Include the cylinder number, Parallels to crank and at 90 deg to crank and at 3 different depths, Chances are the the rear 2 are going to have swollen several thousandths compared to the front 2, and the rear 2 are going to be tapered larger at BDC of the piston deck... Most of the time this is the case and I am sorry to say that this makes the TOP HAT sleeves furnished as a Kit for these engines useless. I hope you still have your receipt for that kit you are likely going to send it back and recoup your money... There are several companies that make standard sleeve stock in several sizes, In the past I have chosen California T sleeves, They manufacture a sleeve that is close enough in it's original form that you will need to bore your block about 0.017 over in order to fit the sleeve Which gives you a really nice clean fit that will also transfer heat properly, The flange for the top of the sleeve can be cut with the same boring bar while it is already centered in the hole by only changing the cutting tool.. A properly installed T flange sleeve does not need to be pinned at all, you want the top of the sleeve flange to stand about 0.005 proud of an already properly decked head gasket surface.. In general this is what gets you the durability you need to have, to get a satisfactory ROI on the money you spend doing it. You get the performance you want by bringing the torque curve down into a useable range and also increasing the overall torque which is done with a special cam grind paired with different Valve springs...There are tricks with changing the bore slightly and a few other machine shop tricks, that no one will know to do if you don't ask for it.. I can send some of that to you in a DM if you want it, I just don't want to put all of my tested trade information online... Some of the information is somewhat simple, For instance the rod bearings for a Buick 225 V 6 are Identical to rover and sell for a fraction of the money, There are maybe 12 different parts That are not suppose to fit a rover that not only fit but preform better than OEM stuff.. I Have cam card info and stuff like that also, A custom ground cam does not cost any more than an OEM rover cam, but the right one can really wake them up and still idle smooth as silk.. If you follow this method the finished product ends up being a really tough package..
Yes you need to stay with a 4.0, I hope you understand the reasons, I personally will not build a 4.6 for a customer I will repair one with disclaimers but not a rebuild.. The risk of a premature failure is to High, I don't care for loosing money to make things right with people, When I did my first one many Years ago I did a bunch of research, and came up with a really good build formula that was tested, I have added some things I have learned on my own over time, That makes the builds even better in my opinion, I think I have done about 25 of these now and all are still running except for a couple that got busted in accidents, a few of them are not even in the truck I built them for any more and I have lost track of a few of them.. It is definitely a large enough sample to say that this works in real life for sure.. I started turning rovers away in my shop again after I had an accident a couple of years ago, But I have been getting more requests again lately.. Any kind of work on a Rover gets expensive. .And one of the last D2s I did my customer Thought I was trying to hose him hose something After that I just halted any further work on the vehicle and he came and got it much later, I just sorta said to my self I am done with Rovers... But I keep getting requests.. Normally my shop is full of Farm tractors diesel trucks and Industrial equipment.. Lots of things we work on are as or more complicated that a Rover in general.. And I suppose the thing that has kept me in business like this is simply being a real stickler for quality.. Some tractors have week points and we figure out how to fix the week points, Many times it requires making some of our own parts..
Now a Bunch of guys will come on and leave messages about a 4.6 engine that makes huge horse power and has been completely reliable.. Yes and they get built to crazy levels and Guys road race them in Triumph TR8S.. But those vehicles are so light that the throttle is rarely wide open for more that a few seconds at a time and the cooling system has ample time to absorbe heat.. Put a camper behind it and head up hill in the mountains where the throttle is nearly wide open for 15 minuets to half an hour at a time, and the results are not the same..
Hahaha, well I have knowledge because so many of them fail, I did my first one because my accountant owned it and he was almost desperate to trade out services..(LOL)...NO Kidding, 2 years later I was getting them from all over...I will try not to bore you to much, But if you want long term durability you need to stay with a 4.0 so that you get away from the hot spot sleeve issue, So you are going to want a long nose 4.0 crank and rods, ( Rotational assembly), You need to keep the fire deck above the water jacket.. Whether you use a 4.0 or 4.6 block would have to be determined by the actual block that you are looking at.. Don't commit to any block before you have removed the sleeves and had the block hot tanked, After hot tank have a really close look for cracks on the inside of the counterbores especially the rearmost ones, If that's a Pass then Pressure test, then check for line bore both on the crank and cam bosses; if it's a pass on that then have the machine shop hit the cylinder counterbores with a sunnet hone Just enough to get the Oxidation off for a good set of measurements Keep good notes Include the cylinder number, Parallels to crank and at 90 deg to crank and at 3 different depths, Chances are the the rear 2 are going to have swollen several thousandths compared to the front 2, and the rear 2 are going to be tapered larger at BDC of the piston deck... Most of the time this is the case and I am sorry to say that this makes the TOP HAT sleeves furnished as a Kit for these engines useless. I hope you still have your receipt for that kit you are likely going to send it back and recoup your money... There are several companies that make standard sleeve stock in several sizes, In the past I have chosen California T sleeves, They manufacture a sleeve that is close enough in it's original form that you will need to bore your block about 0.017 over in order to fit the sleeve Which gives you a really nice clean fit that will also transfer heat properly, The flange for the top of the sleeve can be cut with the same boring bar while it is already centered in the hole by only changing the cutting tool.. A properly installed T flange sleeve does not need to be pinned at all, you want the top of the sleeve flange to stand about 0.005 proud of an already properly decked head gasket surface.. In general this is what gets you the durability you need to have, to get a satisfactory ROI on the money you spend doing it. You get the performance you want by bringing the torque curve down into a useable range and also increasing the overall torque which is done with a special cam grind paired with different Valve springs...There are tricks with changing the bore slightly and a few other machine shop tricks, that no one will know to do if you don't ask for it.. I can send some of that to you in a DM if you want it, I just don't want to put all of my tested trade information online... Some of the information is somewhat simple, For instance the rod bearings for a Buick 225 V 6 are Identical to rover and sell for a fraction of the money, There are maybe 12 different parts That are not suppose to fit a rover that not only fit but preform better than OEM stuff.. I Have cam card info and stuff like that also, A custom ground cam does not cost any more than an OEM rover cam, but the right one can really wake them up and still idle smooth as silk.. If you follow this method the finished product ends up being a really tough package..
Yes you need to stay with a 4.0, I hope you understand the reasons, I personally will not build a 4.6 for a customer I will repair one with disclaimers but not a rebuild.. The risk of a premature failure is to High, I don't care for loosing money to make things right with people, When I did my first one many Years ago I did a bunch of research, and came up with a really good build formula that was tested, I have added some things I have learned on my own over time, That makes the builds even better in my opinion, I think I have done about 25 of these now and all are still running except for a couple that got busted in accidents, a few of them are not even in the truck I built them for any more and I have lost track of a few of them.. It is definitely a large enough sample to say that this works in real life for sure.. I started turning rovers away in my shop again after I had an accident a couple of years ago, But I have been getting more requests again lately.. Any kind of work on a Rover gets expensive. .And one of the last D2s I did my customer Thought I was trying to hose him hose something After that I just halted any further work on the vehicle and he came and got it much later, I just sorta said to my self I am done with Rovers... But I keep getting requests.. Normally my shop is full of Farm tractors diesel trucks and Industrial equipment.. Lots of things we work on are as or more complicated that a Rover in general.. And I suppose the thing that has kept me in business like this is simply being a real stickler for quality.. Some tractors have week points and we figure out how to fix the week points, Many times it requires making some of our own parts..
