Some more answers on new blocks

[a325965]

I am Marcus Clayton, Andrew's brother. I may be able to shed some more light on this subject 1. The oil system will be upgraded using a modern pump, possibly GM. This will have to be finalised as there are still unknowns. The pressure we run depends on the forces we apply to the bottom end bearings(we should not let the metal surfaces touch) but it will be a system that can handle 300 bhp. If we use modern oils, there should not be a need for an oil cooler except in heavy duty applications. 2. Much thought has gone into the cooling of the block. Suffice to say that the original block water passage arrangement is not impressive. We are aiming for correct distribution of coolant. We live in Australia and know a lot about overheating! The stock radiator has plenty of capacity for stock, and somewhat elevated power output, but it is not going to cool a 300bhp engine. 3. The rods required are somewhat longer than the MGB or XPAG. We are going to make rods and pistons for our prototypes, but there are some off the shelf items which are candidates. Pistons- the same comments apply. Remember, we have to accomodate 1250 pistons, but make the motor stretchable to at least 1800. MGB stroker cranks can also be accomodated. The standard sump will bolt on. The rod to stroke ratio will end up approaching 2:1, which bodes well for the engine's ability to breathe. This rod ratio also allows us to consider desaxeing (offseting) the crankshaft,which should lead to a worthwhile gain in mechanical efficiency 4. To make an alloy block is feasible, but to achieve a worthwhile weight advantage, new patterns would be required, and the external ribbing would make the finished product look like a Honda block, which is not the point of this exercise. We want to build a drop in XP*G replacement which is as close as possible in appearance to the original, with as much reliability built in as we can muster so we can drive flat out and not be concerned with expensive and increasingly rare pieces being destroyed. It would have been easier to copy originals, but then you will end up with original problems. I enjoy working on the cars, but I enjoy driving them more,and I hate having to trailer them home and then spending weeks looking for parts which are usually worn out and fatigued. We are currently making new axles as Andrew broke one on the Alpine Rally last month, had to weld up the spider gears to lock the axle and did the final 2 days on one wheel drive- but he finished, and got home. That is not going to happen again!

[Andrew Clayton]

Thank you to all who responded to my post about the new blocks. I got alot of feedback both on and off the list and most seemed to be positive although there was also some perfectly understandable scepticism. I think at this stage we will go ahead with the project but I'll have to confirm this with the other people involved. All those who told me they are interested in a block have been noted and I'll let you, and the list in general, know about progress. By the way, the diff we welded up to get home on one axle was not a TC one so don't panic. It was a fairly commonly available (at least here downunder) Holden item and I found a replacement (with LSD!) a week later for very little money. And I would have used your tapered axles Bob but with the non-standard diff, I need bespoke items made with different splines at each end. So older brothers who are engineers and work in the CNC machinery field have their uses despite the way he used to bash me when we were kids!! Cheers to all and thanks for the support and advice. Andrew TC4054 Melbourne, Australia

----- Original Message ----- From: "a325965" a325965@yahoo.com.au> To: mg-tabc@yahoogroups.com> Sent: Sunday, May 15, 2005 12:18 PM Subject: [mg-tabc] Some more answers on new blocks >I am Marcus Clayton, Andrew's brother. > > I may be able to shed some more light on this subject > > 1. The oil system will be upgraded using a modern pump, possibly GM. > This will have to be finalised as there are still unknowns. The > pressure we run depends on the forces we apply to the bottom end > bearings(we should not let the metal surfaces touch) but it will be a > system that can handle 300 bhp. If we use modern oils, there should > not be a need for an oil cooler except in heavy duty applications. > > 2. Much thought has gone into the cooling of the block. Suffice to say > that the original block water passage arrangement is not impressive. > We are aiming for correct distribution of coolant. We live in > Australia and know a lot about overheating! The stock radiator has > plenty of capacity for stock, and somewhat elevated power output, but > it is not going to cool a 300bhp engine. > > 3. The rods required are somewhat longer than the MGB or XPAG. We are > going to make rods and pistons for our prototypes, but there are some > off the shelf items which are candidates. Pistons- the same comments > apply. Remember, we have to accomodate 1250 pistons, but make the > motor stretchable to at least 1800. MGB stroker cranks can also be > accomodated. The standard sump will bolt on. > The rod to stroke ratio will end up approaching 2:1, which bodes well > for the engine's ability to breathe. > This rod ratio also allows us to consider desaxeing (offseting) the > crankshaft,which should lead to a worthwhile gain in mechanical efficiency > > 4. To make an alloy block is feasible, but to achieve a worthwhile > weight advantage, new patterns would be required, and the external > ribbing would make the finished product look like a Honda block, which > is not the point of this exercise. > > We want to build a drop in XP*G replacement which is as close as > possible in appearance to the original, with as much reliability built > in as we can muster so we can drive flat out and not be concerned with > expensive and increasingly rare pieces being destroyed. It would have > been easier to copy originals, but then you will end up with original > problems. I enjoy working on the cars, but I enjoy driving them > more,and I hate having to trailer them home and then spending weeks > looking for parts which are usually worn out and fatigued. > We are currently making new axles as Andrew broke one on the Alpine > Rally last month, had to weld up the spider gears to lock the axle and > did the final 2 days on one wheel drive- but he finished, and got > home. That is not going to happen again! > > > > > > > Yahoo! Groups Links > > > > > > > > > -- > Internal Virus Database is out-of-date. > Checked by AVG Anti-Virus. > Version: 7.0.308 / Virus Database: 266.11.7 - Release Date: 9/05/2005 > > -- Internal Virus Database is out-of-date. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.11.7 - Release Date: 9/05/2005