MG-Cars.com
MG TD TF 1500 xpeg versus xpag engine BBS discussion at MG-Cars.net
MG-Cars.net
Welcome to our resource for MG Car Information.
Recommendations
Parts
MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.
MG TD TF 1500 - xpeg versus xpag engine
| Gentleman please educate me. What is the difference between xpag and xpeg engine and how to recognise it. Thanks for your time, Gerard |
| Gerard Hengeveld |
| Gerard, the XPAG is nominally 1250 cc, whereas the XPEG is 1466 cc and was used in the late TF's. You can recognise them by the casting numbers or the engine prefix. Regards, Don TF 4887 'Figaro' |
| D J Walker |
| Gerard, The TF 1500 blocks are becoming more and more scarce. It is possible to vigorously over-bore and sleeve an XPAG to about 1466, but its not the same thing. I imagine that the heat distribution would be different. There are TF1500s that have had their XPAG engine replaced with an 1250 XPEG, and Caveat Emptor - the buyer is tricked. Meanwhile a legitimate XPEG has gone into another T. The value of the XPAG-engined TF1500 would thusly be seriously devalued. Here's a very clear picture of the XPEG block, clearly identified by the cast "W in the Diamond" and the Nuffield part number - AEF 117. Gord Clark Rockburn, Qué.  |
| Gordon A Clark |
| Hi Gerald, The TF1500 Cylinder Head is STAMPED AEF 118.Note: On one side of the Head,the water holes are slightly offset compared to a TF1250.Hence the different gasket numbers. The 1500 block is cast no.AEG 117. The 1500 sump has 116 cast into the inside bottom of the sump. The Archives also have a fair deal of information on the differences. Rob Grantham TF3719("Aramis"),TF9177("Athos"). |
| R GRANTHAM |
| Hi Gerard, the XPEG engine has AEF117 cast on the block below where the generator sits. The XPEG head has AEF118 stamped (not cast) on the right front of the cylinder head. The XPAG engines do not have these numbers. Cheers, Hugh |
| H.D. Pite |
| Correction: The TF1500 block is AEF 117,not AEG. Cheers Rob Grantham |
| R GRANTHAM |
| Gerard, No offense, but I think Gord might have confused this a bit: "There are TF1500s that have had their XPAG engine replaced with an 1250 XPEG". A TF1500 would/should have a XPEG (1466cc) engine. TD's as well as some TF's would have a XPAG (1250cc) engine. Because the TF was first built with a 1250 it was simply called a TF. Later in production the XPEG engine was introduced and was then badged as a TF1500. Production continued with both engines being used for a while. Later some "re-named" the TF models TF1250 (XPAG) & TF1500 (XPEG). The Wosley also used a 1500cc engine , and a number of those have found there way into a TF (1250 if you will) so you need to be careful when looking at a TF. The TF1500 badge is available (has been for quite some time) so some people have re-badged these cars The only physical difference (TF/TF1500)being that badge and 2 small reflectors (also available)on the rear of the tub. |
| David Sheward 55 TF1500 # 7427 |
| David, the Wolseley 15/50 had a 1500 cc engine but it was a slightly de-tuned MGA engine. The Wolseley 4/44 had a 1250 XPAW engine which was pretty much the same at the later TD and TF 1250 engine. As far as I know no Wolseley came with the XPEG engine. Hugh Pite |
| H.D. Pite |
| Hugh, Totally agree with what you said. Just that some of the Wolseley 1500's did end up in M.G.'s. (I looked at a TF once that had one.) Was there a "letter" designation for those engines? I can't remember. i.e. 1250 XPAW / 1500 "XXXX" ? |
| David Sheward 55 TF1500 # 7427 |
| Just checked my engine # 654 with a mirror, the diamond and W is cast on the block. The head is difficult to see, even with a mirror, but I did notice a machined surface between exhaust port 1 & 2, almost directly under the front intake port. To check it further, the side panel has to come off and paint removed, that comes later. PJ |
| Paul S Jennings |
| Paul, the cylinder head number should be clearly visible on the top right hand side of the head - at the forward corner of the valve cover and should be visible without removing anything. David, there is some confusion here. The Worseley 15/50 and the Worseley 1500 which came after it (1957-1965) both had the BMC B-series engine like an MGA or Austin Cambridge. They, of course, where not anything like a TF 1500 engine. Many of the Wolseley 4/44 engines ended up in "T" series MG's after the sump, front mounting plate and dipstick position were changed. Cheers, Hugh |
| H.D. Pite |
| I believe that I have also read that the two rear reflectors (the round red ones mounted on the rubber plinths) that are mounted on the rear of the body tub - were introduced for all later TFs not just the TF 1500s. Is this correct. My thinking is that this would not be a good indication point for differentiating a TF1250 from a 1500 |
| DLD |
| Gerard - Here are some on-line resources that have helped me understand the engines. The first one, MG T Series In Detail: TA-TF 1935-55, by Paddy Willmer, is a good overview of engine differences, changes, and identification in a few pages. Scroll down to "Appendices." You should see pp 167-175, however Amazon may omit some of the pages from the preview. If they are missing, send me an email - I will send the complete section to you in .pdf format. > MG T Series In Detail: TA-TF 1935-55, by Paddy Willmer (described above) http://www.amazon.com/MG-Series-In-Detail-1935-55/dp/0954106369#reader_0954106369 > Engines for M.G's - Their Story after 1935, Neil Cairns, amended 11-Dec-2005 http://www.geomatique-liege.be/MGJP/DocumentsPDF/MG_Engine_History.pdf > How to be an Engine Expert on MGs, MG Engines from 1935 to 1998, Neil Cairns, (Book), amended 16-Sept-1998 Same as above, but in book form with photos. The previous link was updated since this book was published. http://www.mg-tabc.org/special-files/how-to-be.pdf > The XPAG Engine - Data, Service, Super-Tuning, WKF Wood, 1968 This is a classic source of info. http://www.dbraun99.com/technical%20index/WKF%20Wood%20XPAG%20Engine%20Book.pdf > Special Tuning for MG midget Engines, MG Car Company Limited, 1954 http://www.dbraun99.com/technical%20index/XPAG-XPEG_SPECIAL_TUNING_COLOR_7.pdf Lonnie TF7211 |
| LM Cook |
| The link to "The XPAG Engine - Data, Service, Super-Tuning", WKF Wood, 1968 may be broken. Here are two more links to the document: http://www.iot.ntnu.no/users/oddk/mg3/downloads/XPAGEngine.pdf http://mgtc.no/downloads/XPAGEngine.pdf Lonnie TF7211 |
| LM Cook |
| Our first TD has an XPEG engine punched out to 1466cc. Since I'm in the process of overhauling it, the core plugs are now removed and, the cylinder walls have been measured at just a touch over .1 inch. It has a lot of years and miles to prove it is sound, but I dare not take the risk of boring it any farther, especially since it'll be set up with a supercharger. |
| JRN JIM |
| DLD, My TF 1500 was built December, 17, 1954 and it has the two reflectors. Disassembling everything, the rubber on them was severely deteriorating and this matching number car sat undercover most of it's life. PJ |
| Paul S Jennings |
| A Big thank you Guy's for the wealth of information you shared . Gerard |
| Gerard Hengeveld |
| Just looked at the head and it has AEF 118 stamped on it! Thanks Hugh, I was looking in the wrong place. So everything looks like it belongs. Didn't see the number on the block, but with the Diamond and W symbol cast on it I guess I don't need to see the number. Happy camper here! PJ |
| Paul S Jennings |
| will an XPAG bored out to 1466cc perform any difrently than an XPEG? David |
| D. Sander |
| Hi Paul - my TF1500 has the reflectors as well - what I have read is that both the 1250 and 1500 cars would have them after a certain point in production. Cheers |
| DLD |
| Learn something new all the time. I was under the impression only the 1500 left Abingdon with reflectors. Read it somewhere a long time ago. I certainly would not go by having reflectors or even a TF1500 badge that a car is a true 1500. Moss has sold both for years! I know for a fact there are TF's out there that were "born" as 1250's that now sport both. (Including at least one with a Volvo 1800 engine in it!) 15 years ago the only way to be sure was verify all numbers with BMHT. We are lucky that that info is now just a mouse click away. Then again we also live in a time where counterfeit everything has never been easier to make! OBTW: On reflectors ...I maybe responsible for a few people adding those to a TF1250 (and at least 1 TD). I have talked to several that put them on after seeing that I put brake/turn signal lamps in mine in order to be seen better 12+ years ago! |
| David Sheward 55 TF1500 # 7427 |
| Dave, don't know how anyone could counterfeit this casting so it looked proper. PJ Oh, anyone know what the W stands for?  |
| Paul S Jennings |
| The reflectors are the result of a rule change, I think in July 1954, so all TF's after that (1250 and 1500) had the reflectors. |
| Don Harmer |
| Dave Sander, As they said a half century ago, "nothing beats cubic inches!" (every cubic centimeteres count, too) Just by crunching the numbers, the 1466 XPEG ought to have about 17% more get-up-and-go. That's actually a better upgrade than a blower! Len will argue the roller lifter cam is a wiser investment, and he's probably right. So my wife's toy will get a blown 1466 XPEG with the roller lifter cam setup. However, if you have a supercharged XPEG, boring the block out will generate no more power, because the belt drive is the limiting factor for the intake. I've got to redo a pulley when the 1466 engine is ready. JIM |
| JRN JIM |
| Paul, agreed and I would think it would hardly be worth it on one of our cars to do so. (No offence intended ...I own one also!) The comment I made: "live in a time where counterfeit everything has never been easier to make!" comes more from conversations with a neighbor of mine that is currently honkering down for a serious battle over his Yenco Camero. Bought the car 10+ years ago and has just found out it is a very, very convincing counterfeit! Seems there are two cars with his vin #. Somebody found the "real one" under a pile of rubble in a junk yard and began a restoration on it. Up till then his had fooled even the experts! |
| David Sheward 55 TF1500 # 7427 |
| Hi Paul, The picture that Gordon Clark showed above, is of my XPEG block. A few years back, someone inquired about how to tell an XPAG block from an XPEG block. I had my block on the bench at the time, so took a thin black felt pen, and went over the markings on the block that identifies the XPEG. I think I read some place that the "W" identifies it as being cast in the Wolsley plant. George |
| G. L. Raham |
Dave, I would hate to be the one who sold the Camero to your neighbour! There could be quite a court battle there and a lot of nastiness. George, Thanks for posting the photo, it provides a good statement of what an XPEG block should look like and with Hughs posting of the numbers, eliminates all doubt. PJ |
| Paul S Jennings |
| Paul, You got that right ...if they can figure out "who" is responsible! Came from a Kansas LLC dealer no longer in business. Only "principle" they have been able to find (of course) denies any knowledge. The level of craftsmanship on vin plates, engine numbers, frame stampings,ect is incredible. Not a happy fellow. |
| David Sheward 55 TF1500 # 7427 |
| Not sure how it's done, but the original stampings can be retrieved by, I believe basically, a chemical and Xray type process. When a piece is stamped, the metal is compressed and a change in the structure is formed, causing the compressed area to show up on a screen. PJ |
| Paul S Jennings |
| On this BBS a couple of times in the past and interesting, précised from a 2004 article by Roger Wilson in MG Car Club T Register magazine ‘TTT’. “Originally these blocks had M, MG, or W cast on them according to the vehicle into which they were to be fitted. By June 1952, Morris Engines were only making the 1250cc version, and undertook substantial changes to the block and head to improve the cooling. This was when the block to head water passages changed from oval to round, plus other changes to the head. However, also by June 1952, the main use of these engines was in the Wolseley 4/44, so Morris Engines probably decided they didn't want to produce special castings and batches of engines that were unique for MG. Thus they only continued to use the W casting boxes for the blocks, although they obviously changed the internal cores to incorporate the modifications. New casting numbers were introduced, and they are visible on the block and head. Later on, when the bore walls were moved out and other water passages moved to produce the XPEG block and head, Morris Engines probably only modified the cores of one or two casting boxes (of head and block), although they did change the casting numbers. The block became AEF117, but on the head, although the old number was (badly) filled in, it seems they forgot to engrave the new number; thus after casting, and possibly some more cleaning up, someone stamps on AEF118. “As the XPEG engine was only used in the MG, you could ask why they didn't do the necessary block changes to some of the old MG casting boxes (for blocks) that they had lying around since June 1952. That I don't know; it is possible that they (Morris) were thinking of putting the 1466cc engine into the Wolseley 4/44 - who knows! It is more likely that they had already "changed" the MG boxes into W boxes. - XPAG casting numbers; Oval water hole, head 22952 block 24142, then 24146, then 24445 Round water hole, head 168422 block 168421 - XPEG casting numbers; head AEF118 (stamped on) block AEF117 |
| Steve Gee |
Gentlemen, Having rebuilt a few XPEG engines over the years and scoured the auto jumbles for spare blocks, here are a few tips for spotting a XPEG block from a XPAG block. The first thing I look for is on the rear of the block there is a horizontal web or rib running from the core plug hole at 6:00 down to bell housing portion and blending into it. You can find this easily on the engine, even if it is installed in the car by just feeling for it with your fingers. I exposed a fraudulent TF 1500 years ago at a Concours D’ much to the owner’s dismay and protests to the contrary . He later came clean to his rouse. Another way, but more involved, is if the large center core plug is removed and the external cylinder surfaces are visible, there is no water passage or gap between cylinders 2&3, they were cast as one. On the XPAG blocks there is about a 4-5 mm gap between the cylinders, presumably the gap was lost to make room for the larger bore size. Don’t give up the search for the elusive XPEG blocks, I found one just a few years ago in a metal recycling yard, they charged me $00.18 a pound for it, the going rate for scrap iron! Cheers, Terry P. |
| A Peddicord |
| Hi Lonnie, The articles on Engines are generally very informative. However,a correction is in order where reference is made to XPAG TF Cylinder Head numbers. The correct TF 1250 number is 168425 not 168422 as has been listed.The five(5)is stamped in and the other numbers are cast. Wolseley 4/44s have cylinder head numbers 168422,not 168425! Cheers Rob Grantham TF3719("Aramis"),TF9177("Athos") |
| R GRANTHAM |
| Thanks Rob. I'm the new kid on the block ... I've owned my TF-1500 only since December and less than half of that time with the correct AEF118 head. I find these little tid bits facinating. If the basic casting was the same before machining, then I see why the plant would grind off the "2" and stamp "5" in its place for the revised head. The entire casting number was ground off of the TF-1500 head and stamped with "AEC118". I read a little deeper into the links that I posted: Willmer says that the 168425 head was used on TD MkII and all TF-1250s. #168422 was the original casting number when the water holes were changed to round in 1952. Looks like Cairns made the statements with which you disagree. He says that 168425 was used on late Wolseley 4/44, but that 168422 was used on earlier 4/44, TD & TF (1250) with round water holes and long reach plugs. Neither author notes that the last digit was stamped. I'll go with your experience. Lonnie TF7211 |
| LM Cook |
| Interesting discussion - a mate has a 1500 XPEG surplus to his needs, but we are uncertain what it's worth to sell. I have driven a car with this engine fitted (a YA), and it requires no re-building in any form. The YA has had it's original 1250 XPAG fitted, so the 1500 engine is now "spare". But what is it worth in $AUD ?. Cheers Tony |
| A L SLATTERY |
| Just read this and, although I'm late, I'd like to contribute. If you put a 4/44 engine into a T Type,as well as the other changes mentioned there is one thing you absolutely MUST do. CHANGE THE OIL INTAKE PICKUP IN THE SUMP SO IT SUCKS FROM THE CENTRE, NOT THE LEFT SIDE! Depending on the sump you fit, you may or may not be able to fit the intake 'duckbill. My TF did exactly one quarter of a lap on the track before, on the first left-hander, it ran all its bearings. A DPO had put in a 4/44, but hadn't bothered with a centre pickup. Regards, David PS Tony, the answer is 'Lots". I guess you know that by now.  |
| D A Provan |
| Hi Guys, On removal of appropriate core plugs, cylinders 2 and 3 are not cast together in either type of block. It is cylinders 1 & 2 are cast together as are cylinders 3 & 4 in the XPEG block. There is a small gap between these in the XPAG block. Bob Schapel |
| R L Schapel |
| Just read this thread for the first time so apologies for being late! I would think it extremely unlikely that the reflectors can be relied upon as evidence of an XPEG engine. I was able to look at the TF production records the other day (doing some research on my car) and the TF 1500 XPEG and TF 1250 XPAG were built in alternate batches over a period of time in late 1954. It looks like most of the early 1500s were for export to the USA, and the 1250s were for home and other markets. In fact, only 1250s were shown at the London Earls Court motor show in October 1954. This being so, I wouldn't be surprised if reflectors were introduced at the launch of the 1500 and also fitted to 1250 cars. Alternatively, it could be that reflectors were introduced for the US market only. ATB Richard |
| R J Woollaston |
| Rear reflectors were fitted because of UK legislation and were compulsory as from 1 October 1954. Here's the House of Lords debate on the Bill which unusually was a Private Members Bill. The references to 'another place' are how members of the House of Lords refer to the House of Commons - and still do. http://hansard.millbanksystems.com/lords/1953/may/07/road-transport-lighting-rear-lights-bill David |
| David Wardell |
| Interesting - that means there will be a small number of UK market TF1250s fitted with reflectors as the TF1500 hadn't been launched in the UK market by 1 October 1954. Thanks, Richard |
| R J Woollaston |
| David Wardell, That is an interesting fact since my TF 1500 #7157 was built 22-23 September 1954 and has the reflectors. Jack |
| Jack Long |
| As I understand it he reflectors were added in production in July 1954 (see parts list) in anticipation of the passage of the pending legislation. So all TF 1500's and the co-manufactured 1250's had the reflectors. Note that the legislation also required that they be retrofitted to vehicles manufactured before OCT 1, 1954 but with a much later compliance date (1957 I think) Don H. TF 1500 |
| Don Harmer |
| Hi Tony, I could be interested in the TF1500 EPEG motor but have no idea as to what one is worth. Would be buying as a back up spare. I live on the Sunshine Coast. So if you want to contact me my number is 07 54426860 or 0421 998447. Cheers John |
| J.K. Chester-Freeman |
Hi everyone I have an interesting dilemma. I own a 1954 mgtf the registration docs tell me it's an XPAG version the badge on the engine says XPAG but the actual engine is an XPEG as it has AEF 118 and AEF 117 on the head and block. This engine has been in the car as long as we have owned it which is over 50 years. My dilemma is that I am currently rrestoring the car and the engine is in a very bad way. Should I replace it with a XPAG as per the original or should I get the XPEG rebuilt (if this is possible). Any advice would be much appreciated. Thanks. lambdarryl@gmail.com
 |
| D Lamb |
| D. Lamb Since the engine is not the original, you would gain nothing by replacing the XPEG with an XPAG, it still would not be the original. In fact you would lose in performance ( and value). Rebuild the XPEG by all means, parts are available as with XPAG parts. Most parts are the same, except for pistons and rings and the crank is of the better steel, (less likely to break). Most of us would prefer to have an XPEG instead of an XPAG, except for true concours reasons. No one at a regular car show is going to fuss at you for having a non-original engine as long as it an engine from a T car. Note, you will notice the extra power easily of the XPEG;s 1500 cc. |
| Don Harmer |
| Don Harmer Great advice and makes a lot of sense. Fingers crossed that the engine will take a rebuild. Hadn't realised that there might be a value impact in this decision. But I guess original TF XPEG engines are less common than XPAGS. Thanks again Darryl |
| D Lamb |
| the XPEG is much rarer, since only about 3800 were made versus 33,000 not including the XPAW for Wolsley and the one made for the YA/YB. And most of the 1500's were sent to the USA. Don H |
| Don Harmer |
This thread was discussed between 05/07/2014 and 03/11/2014
MG TD TF 1500 index
This thread is from the archive. The Live MG TD TF 1500 BBS is active now.