New XPEG Blocks - some answers.

[Andrew Clayton]

There's been quite a response to my post yesterday about new and improved XPEG blocks, both on and off the list. I'll try to answer all the questions and respond to all the comments so far:- 1. The crank we will use will be, as some of you have already guessed, an MGB 5-bearing item - as I said, easily available and not too expensive. It has a stroke of 88.9mm (compare with XP*G of 90mm) and will fit lengthways into the block with small modifications to the block for modern seals at each end. 2. I made an error when I said "If for any reason you would want to use a standard 3 bearing XP*G crank, the 2 extra bearing bridges in the block could easily be machined out." A standard 3-bearing XP*G crank will not fit but an MGB one will and this is what I meant. Sorry about that. I should point out that the only reason we can think of to use a 3 bearing crank would be if race regs do not allow you to alter the number of main bearings. 3. The bearing bridges are an integral part of the block bottom end casting so retro fitting the extra bearing bridges into a standard block is not feasible. 4. As for shipping costs, I guess it depends on volume. As a one off, it would probably be $300 to $500 (Aus) to the USA but if there were orders for 10 or 20 and we could share a container with someone else, I'm sure this would come down alot. 5. Ron Simon asked why do it? Well, if you have a standard car and use it mainly for show and gentle driving then I agree. I'm not sure about the comment about there being plenty of 1250 blocks around, but even if it's true, how many 1500 blocks are there? And those that are around are now over 60 years old with fatigued and porous metal having been made with old techniques and casting technology. In addition, remember that our blocks will be able to be bored out further, up to 1900 if desired. Ron said that the 1250 blocks can be machined out to 1500 but at what cost, not only financially and also in terms of reliability? This would be the absolute limit for a 1250 but it's only the starting point for our blocks. His engine has lasted 10,000 miles and that's terrific but whatever mileage you get before a rebuild, I guarantee that if you use one of our blocks putting out similiar power, you will get much, much more. So he asks what value would a 5 bearing crank have - well, I would have thought it was fairly self evident. Why did MG change the MGB engine from 3 to 5-bearings in the late '60's? We believe that you will be able to build a strong, powerful, reliable motor with one of our blocks at much the same cost as rebuilding an XPAG/XPEG to produce similiar power. The difference will be that ours will be virtually bulletproof and will far outlast an engine with the original block. No more broken XP*G cranks here!! 6. The cam and lifters are entirely up to you. We will add some metal in this area but it will be machined to accept a standard cam. Basically, any cam you would use in a stock XP*G, you could also use in our block. The extra metal is there to accomodate roller or mushroom lifters if desired. The base circle diameter of cam can be increased to allow modern cam profiles and ramps.(not needle bearings here). 7. We will cast the blocks with vanadium laced iron. I'm not an expert in this but apparently this ore came from Canada originally and is perfect for this type of application. I can get more details if anyone is interested, or someone on the list may know more about this. We did consider aluminium but have ruled it out at present because we would have to make new patterns for the casting and the extra thicknesses required for strength will probably mean the weight savings would be debatable. 8. The original cast iron head, whatever style you have, will bolt on. We are moving the bores apart which will actually help centre them with the combustion chambers. Yes, that's right - a close inspection of a standard block and head reveals that the combustion chambers and bores are not centered - this can't help volumetric efficiency. When you bolt the head on to one of our blocks, you might notice a step at the front and back because the bigger separation of the bores but you will have to look hard. The ability to use a standard head (and all other ancillaries) was critical to our plan and we wouldn't have thought about going any further had this not been the case. The greater wall thickness will allow bores to remain round under pressure and the block will not walk which leads to friction bearing wear and oil leaks. The block is actually engineered for 300bhp - whether you want this in a T-series is a moot point but it gives you an idea of the design and strengthening work we are putting in. 9. Finally, to all those that want to drive completely standard cars with original steering, engines, gearboxes, diffs, etc, fine, go ahead and enjoy yourselves. Our project is probably not what you want for your car and I have no problem with that. However, there are those who enjoy racing or having faster and safer than standard road cars and they are probably the ones who might be interested in these blocks. I'm not sure how far you can go with originality anyway. Does your car have the same air in the tyres, oil in the engine, brake fluid, etc. as when it was built? Have you never used a remanufactured and/or modern part to keep it on the road? What about your battery, fuel pump, rear axles and seals, front wheel bearings and so on? And, as many discussions on this list show, who really knows what was original anyway? I've lost count of the number of cars I've seen (not only T-types) which have been "restored" to within an inch of their lives, probably ending up better than they ever were when they left the factory and losing all character in the process. Mine is a scruffy old thing with many modifications, most of them done over the life of the car and, in my opinion, it's a living and still developing piece of history. I love it. That's my opinion and it's my car, so I guess we'll never agree. The fact is that we all love our cars in different ways with all their idiosyncracies and "soul", and we're all doing our best to keep them on the road. Live and let live I say ......Oh, and to Julian who preached originality and bemoaned the fact that we are all modifiying our cars away from standard, I didn't know the factory supplied Laystall heads and 1350 motors as standard. Your car must have been a prototype - lucky you! Cheers, Andrew Clayton TC4054 Melbourne, Australia. ---------- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.11.7 - Release Date: 9/05/2005 [Non-text portions of this message have been removed]

[Gene Gillam]

Andy wrote: "Finally, to all those that want to drive completely standard cars with original steering, engines, gearboxes, diffs, etc, fine, go ahead and enjoy yourselves. Our project is probably not what you want for your car and I have no problem with that." Exactly my point yesterday - to each his/her own. "Mine is a scruffy old thing with many modifications, most of them done over the life of the car and, in my opinion, it's a living and still developing piece of history. I love it. That's my opinion and it's my car, so I guess we'll never agree." I love the look of your car, Andy. For those you who haven't taken the time to glance at the member's car section to see it, here's the link: http://www.mg-tabc.org/a_clayton.htm All the best....and you'll get a deposit from me, btw...the savings in the cost of an MGB crank compared to that of an XPAG one will help pay for the block... Gene Gillam Saucier, MS -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.11.10 - Release Date: 5/13/2005

[Ron Simon]

Andrew, thank you for the responses and comments. I built a complete 1500 motor starting from scratch, new block,crank, XPEG sump, etc. for far less than what I believe your motor will finally cost. As far as gentle driving ! I have seen over 80 mph indicated several times, with 2 up and loaded with luggage. I also have a few questions about the project. What changes to the oiling system do you propose. Isn't the MGB pump of larger capacity? also all MGBs have oil coolers as standard equipment. Since the stroke is shorter will the bores be larger & if so does the head need to be modified to fit. What type of connecting rods will you be using, Carello/Christiansen or ? Will you change the water pump? Does the TC radiator have the capacity to cool this improved motor especially if you increase the hp. It is still a very interesting project that you propose. Carl Cedarstrand of the Vintage MG Club of So Calif. has the plans and I believe the prototype and tooling for the "Runyan" dual overhead cam replacemant head for "T" series cars. Wouldn't that be a great combination for your project. Regards, Ron Simon --- Andrew Clayton andyc@alphalink.com.au> wrote:

> There's been quite a response to my post yesterday > about new and improved XPEG blocks, both on and off > the list. I'll try to answer all the questions and > respond to all the comments so far:- > > 1. The crank we will use will be, as some of you > have already guessed, an MGB 5-bearing item - as I > said, easily available and not too expensive. It has > a stroke of 88.9mm (compare with XP*G of 90mm) and > will fit lengthways into the block with small > modifications to the block for modern seals at each > end. > 2. I made an error when I said "If for any reason > you would want to use a standard 3 bearing XP*G > crank, the 2 extra bearing bridges in the block > could easily be machined out." A standard 3-bearing > XP*G crank will not fit but an MGB one will and this > is what I meant. Sorry about that. I should point > out that the only reason we can think of to use a 3 > bearing crank would be if race regs do not allow you > to alter the number of main bearings. > 3. The bearing bridges are an integral part of the > block bottom end casting so retro fitting the extra > bearing bridges into a standard block is not > feasible. > 4. As for shipping costs, I guess it depends on > volume. As a one off, it would probably be $300 to > $500 (Aus) to the USA but if there were orders for > 10 or 20 and we could share a container with someone > else, I'm sure this would come down alot. > 5. Ron Simon asked why do it? Well, if you have a > standard car and use it mainly for show and gentle > driving then I agree. I'm not sure about the comment > about there being plenty of 1250 blocks around, but > even if it's true, how many 1500 blocks are there? > And those that are around are now over 60 years old > with fatigued and porous metal having been made with > old techniques and casting technology. In addition, > remember that our blocks will be able to be bored > out further, up to 1900 if desired. Ron said that > the 1250 blocks can be machined out to 1500 but at > what cost, not only financially and also in terms of > reliability? This would be the absolute limit for a > 1250 but it's only the starting point for our > blocks. His engine has lasted 10,000 miles and > that's terrific but whatever mileage you get before > a rebuild, I guarantee that if you use one of our > blocks putting out similiar power, you will get > much, much more. So he asks what value would a 5 > bearing crank have - well, I would have thought it > was fairly self evident. Why did MG change the MGB > engine from 3 to 5-bearings in the late '60's? We > believe that you will be able to build a strong, > powerful, reliable motor with one of our blocks at > much the same cost as rebuilding an XPAG/XPEG to > produce similiar power. The difference will be that > ours will be virtually bulletproof and will far > outlast an engine with the original block. No more > broken XP*G cranks here!! > 6. The cam and lifters are entirely up to you. We > will add some metal in this area but it will be > machined to accept a standard cam. Basically, any > cam you would use in a stock XP*G, you could also > use in our block. The extra metal is there to > accomodate roller or mushroom lifters if desired. > The base circle diameter of cam can be increased to > allow modern cam profiles and ramps.(not needle > bearings here). > 7. We will cast the blocks with vanadium laced iron. > I'm not an expert in this but apparently this ore > came from Canada originally and is perfect for this > type of application. I can get more details if > anyone is interested, or someone on the list may > know more about this. We did consider aluminium but > have ruled it out at present because we would have > to make new patterns for the casting and the extra > thicknesses required for strength will probably mean > the weight savings would be debatable. > 8. The original cast iron head, whatever style you > have, will bolt on. We are moving the bores apart > which will actually help centre them with the > combustion chambers. Yes, that's right - a close > inspection of a standard block and head reveals that > the combustion chambers and bores are not centered - > this can't help volumetric efficiency. When you bolt > the head on to one of our blocks, you might notice a > step at the front and back because the bigger > separation of the bores but you will have to look > hard. The ability to use a standard head (and all > other ancillaries) was critical to our plan and we > wouldn't have thought about going any further had > this not been the case. The greater wall thickness > will allow bores to remain round under pressure and > the block will not walk which leads to friction > bearing wear and oil leaks. The block is actually > engineered for 300bhp - whether you want this in a > T-series is a moot point but it gives you an idea of > the design and strengthening work we are putting in. > 9. Finally, to all those that want to drive > completely standard cars with original steering, > engines, gearboxes, diffs, etc, fine, go ahead and > enjoy yourselves. Our project is probably not what > you want for your car and I have no problem with > that. However, there are those who enjoy racing or > having faster and safer than standard road cars and > they are probably the ones who might be interested > in these blocks. I'm not sure how far you can go > with originality anyway. Does your car have the same > air in the tyres, oil in the engine, brake fluid, > etc. as when it was built? Have you never used a > remanufactured and/or modern part to keep it on the > road? What about your battery, fuel pump, rear axles > and seals, front wheel bearings and so on? And, as > many discussions on this list show, who really knows > what was original anyway? I've lost count of the > number of cars I've seen (not only T-types) which > have been "restored" to within an inch of their > lives, probably ending up better than they ever were > when they left the factory and losing all character > in the process. Mine is a scruffy old thing with > many modifications, most of them done over the life > of the car and, in my opinion, it's a living and > still developing piece of history. I love it. That's > my opinion and it's my car, so I guess we'll never > agree. The fact is that we all love our cars in > different ways with all their idiosyncracies and > "soul", and we're all doing our best to keep them on > the road. Live and let live I say ......Oh, and to > Julian who preached originality and bemoaned the > fact that we are all modifiying our cars away from > standard, I didn't know the factory supplied > Laystall heads and 1350 motors as standard. Your car > must have been a prototype - lucky you! > > Cheers, > > Andrew Clayton > TC4054 > Melbourne, Australia. > > > ---------- > > No virus found in this outgoing message. > Checked by AVG Anti-Virus. > Version: 7.0.308 / Virus Database: 266.11.7 - > Release Date: 9/05/2005 > > > [Non-text portions of this message have been > removed] > > > > > Yahoo! Groups Links > > > mg-tabc-unsubscribe@yahoogroups.com > > > > >

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[Donald Wilkinson]

digitaldon finds this post MOST interesting. 1. FASCINATED to hear that Carl has the Runyan stuff; always wondered what became of it. digitaldon had corresponded with that guy, (Norman Timbs?), back then when the project folded, and all the drawings, patterns, & a prototype or two were up for grabs, but nothing came of it. 2. Ron asks about a water pump change...........REALLY interesting. This suggests a possibility of instituting reverse flow cooling, i.e. (the coolest) H2O entering the head and exiting from the block. With end-to-end flow, this oughta solve T series cooling issues, particularly when dealing with 300 BHP, and particularly where forced induction was involved. Where serious boost (an atmo or more), is involved, serious heat from most any turbo/supercharger setup must be dealt with. Don TC 7993 Grand Island NY USA