Rippthrough 98 Posted October 18, 2006 "something silly like a 2+mm skim" No more scientific than my post! But different nonetheless! A low pressure supercharger would save all this hassle Share this post Link to post Share on other sites
RossD 43 Posted October 18, 2006 But different nonetheless! A low pressure supercharger would save all this hassle But add about £1000 to the build price! I'm staying N/A Share this post Link to post Share on other sites
Rippthrough 98 Posted October 18, 2006 But add about £1000 to the build price! I'm staying N/A Fair enough Someone on here had the combustion chamber sizes didn't they?, If I remember rightly ( ) the Tu3S head is about 36cc? Or was that what was needed? Share this post Link to post Share on other sites
stu_woac 1 Posted October 18, 2006 I dont think all ma boxes are chocolate mines taking a bashing and living to tell the tale, also crown wheel has not come off the quife yet proving getting the job done right is the way to go LOL Share this post Link to post Share on other sites
Sandy 189 Posted October 18, 2006 I've had two MA boxes take a severe bashing, then suddenly go down hill rapidly. Funny business! The BE is nicer to use (IMO of course) and the first to second rev drop is less with the right ratios. I've got early and late heads here, if I hadn't been flat out all day i'd go and cc them now, i've been messing around mostly with XU heads recently so I think i'll avoid saying what cc which head is, unless I get it mixed up. But from distant memory, I think it was 28cc for the TU3S and 36cc for the later black tops. But i'll try and get of my ass in the morning to confirm that. Share this post Link to post Share on other sites
RossD 43 Posted October 19, 2006 I've had two MA boxes take a severe bashing, then suddenly go down hill rapidly. Funny business! The BE is nicer to use (IMO of course) and the first to second rev drop is less with the right ratios. I've got early and late heads here, if I hadn't been flat out all day i'd go and cc them now, i've been messing around mostly with XU heads recently so I think i'll avoid saying what cc which head is, unless I get it mixed up. But from distant memory, I think it was 28cc for the TU3S and 36cc for the later black tops. But i'll try and get of my ass in the morning to confirm that. Cheers Sandy. I had tried to work out the chamber volume from the compression ratio on the TU3S, but forgot they had slightly dished pistons and came to a figure ~40.5cc, so chamber + gasket + piston (maybe!) I'll measure it when I get my TU5J2 head, over the weekend to confirm. I agree about the BE box, having had them in the last 3 cars, currently got a BE4R box in a 406 HDi. Longer throw than the MA (that could be down to the linkage setup though) but smoother overall. Might look into fitting a BE4R/BE4 box, but the bell housing is different on the DW engines. I *think* using the correct bellhousing/adaptor it could be made to fit a TU engine. (Starter on front of EW/DW, starter at back on TU) Share this post Link to post Share on other sites
trogboy 17 Posted October 19, 2006 I measured the TU3S combustion chamber at 28.6cc and the TU24 chamber at 32.4cc if that helps. I've not measured the TU5 head but the combustion chambers seem identical to the TU24 one. I have also run loads of calcs to determine the theoretical compression ratios for several combinations of TU24, TU3S and other odds and sods including the domed pistons you are looking at from the 1360cc 106 XSi. You can pick my brains if you think it may contain something you need. Ad Share this post Link to post Share on other sites
RossD 43 Posted October 19, 2006 I measured the TU3S combustion chamber at 28.6cc and the TU24 chamber at 32.4cc if that helps. I've not measured the TU5 head but the combustion chambers seem identical to the TU24 one. I have also run loads of calcs to determine the theoretical compression ratios for several combinations of TU24, TU3S and other odds and sods including the domed pistons you are looking at from the 1360cc 106 XSi. You can pick my brains if you think it may contain something you need. Ad Ok, as I'm unable to know the size of the dome on the crown, I am presuming that using the TU5J2 head and domed pistons will give 9.9:1 (E.g same as TU3J2), so how much of a skim would be needed to raise it to 10.5:1...... Share this post Link to post Share on other sites
christopher 5 1 Cars Posted October 19, 2006 I measured the TU3S combustion chamber at 28.6cc and the TU24 chamber at 32.4cc if that helps. I've not measured the TU5 head but the combustion chambers seem identical to the TU24 one. I have also run loads of calcs to determine the theoretical compression ratios for several combinations of TU24, TU3S and other odds and sods including the domed pistons you are looking at from the 1360cc 106 XSi. You can pick my brains if you think it may contain something you need. Ad Ad the TU24 combustion chamber is designed for 75mm bore and a TU5 for a 78.5 bore. So I would expect that the diameter is different as with the contour (and with that cc). But I cannot confirm this since I don't have a TU5 head. Share this post Link to post Share on other sites
RossD 43 Posted October 19, 2006 Ad the TU24 combustion chamber is designed for 75mm bore and a TU5 for a 78.5 bore. So I would expect that the diameter is different as with the contour (and with that cc). But I cannot confirm this since I don't have a TU5 head. The TU3J2 head and the TU5J2 head are identical, even the same part number on the Peugeot parts database, so I'll measure mine over the weekend and report back Share this post Link to post Share on other sites
trogboy 17 Posted October 19, 2006 Well spotted Chris, I meant the TU3J2 head as found on the 1.4 106 XSi not the TU5. I've never even seen a TU5 head in the flesh so I wouldn't like to say either way but if they really are the same part no. then they should be identical. If the TU3J2 engine is 9.9:1 as stock then perhaps the combustion chamber is of a slightly larger size than the TU24 head. I recon a TU24 head on a TU3J2 bottom end will make 10.2:1. To raise the compression from 9.9:1 to 10.5:1 with a TU3 bottom end you'd need to remove approx 2.4cc from the combustion chamber volume (per cylinder). This equates to a skim of approx 0.55mm. Share this post Link to post Share on other sites
RossD 43 Posted October 19, 2006 Well spotted Chris, I meant the TU3J2 head as found on the 1.4 106 XSi not the TU5. I've never even seen a TU5 head in the flesh so I wouldn't like to say either way but if they really are the same part no. then they should be identical. If the TU3J2 engine is 9.9:1 as stock then perhaps the combustion chamber is of a slightly larger size than the TU24 head. I recon a TU24 head on a TU3J2 bottom end will make 10.2:1. To raise the compression from 9.9:1 to 10.5:1 with a TU3 bottom end you'd need to remove approx 2.4cc from the combustion chamber volume (per cylinder). This equates to a skim of approx 0.55mm. A reasonably big skim, but within the realms of possibility then! Just gotta see what it does to the squish area within the head, hopefully it wont effect it too much. Hopefully, I'll be getting some domed pistons from Sandy309 (If they turn out to be ok!) and so spec at the moment is looking like: TU5J2/TU3J2 Head on TU3S bottom end (Bottom end reconditioned, E.g new main/big end bearings, crank checked, check and rehone liners, maybe new oil pump) TU3J2 Pistons (Will put new rings on) Jenvey SF bodies (From Sam) Cam (Still undecided, but probably the one recommended at start of this post) Megasquirt injection/igntion Share this post Link to post Share on other sites
trogboy 17 Posted October 19, 2006 If you really wanted to you can take anything up to 2mm off these heads before you get close to oilways etc but like you said it depend on how it effects the squish area. Personally I think you'll find that it will make little difference but then I'm no expert. You might be getting little tight in the way of static clearance between the crown and the valves though. The crown of the TU3J2 pistons is quite tall at ~4.12mm proud of the face which means that the top face is ~5.15mm higher than the base of the depression of the TU3S piston. You are basically building a TU3J2 with a heavy skim and making use of an alloy block but I don't know how much static clearance they run as stock. In the end I guess it will also depend on what lumpy stick you decide on and what you'll be doing with the cam timing. I am currently putting my engine together using a heavily skimmed TU24 head with a stock TU3S bottom end. I'm going to run it like this for now and see how she runs. In the future I might get hold of a set of the TU3J2 pistons and have them machined down almost flat as this would give me a CR in the mid to high 10s whilst leaving me the required clearance. I kind of buggered myself by skiming so much off the head but at the time my goals were slightly different. Still I've got a week off next week to get it finished an in the car - you never know, it might just happen. Share this post Link to post Share on other sites
Rippthrough 98 Posted October 19, 2006 (edited) The tu3s head I have here actually has the squish area recessed about .3mm from the face of the head, so if you're lucky you might actually improve things. -Phillip Edited October 19, 2006 by Rippthrough Share this post Link to post Share on other sites
trogboy 17 Posted October 20, 2006 Similar on the TU24 heads Philip as the first mm of the combustion chamber is effectively cylindrical. That was the on of the reasons I opted for a heavy skim as at the time I wasn't aiming for very high CR and I didn't want the domes of the TU3JP pistons intruding into the combustion chamber too far effectively making it n shaped which obviously isn't a problem with the TU3S pistons. Share this post Link to post Share on other sites
RossD 43 Posted October 22, 2006 Right, got the head and have measured the chamber volume to be 32.5cc, so the same as the TU24 head (32.4cc). Share this post Link to post Share on other sites
christopher 5 1 Cars Posted October 22, 2006 Whats the diameter of the combustion chamber? Share this post Link to post Share on other sites
RossD 43 Posted October 22, 2006 Whats the diameter of the combustion chamber? About 75mm... The headgasket for the TU5 engine left marks where the firerings were, and these are wider than the actual chamber. The TU3 gasket will thus fit without covering any of the chamber Share this post Link to post Share on other sites
christopher 5 1 Cars Posted October 22, 2006 About 75mm... The headgasket for the TU5 engine left marks where the firerings were, and these are wider than the actual chamber. The TU3 gasket will thus fit without covering any of the chamber Where does this head come from now? I'm a little confused...XSI or TU5? Share this post Link to post Share on other sites
RossD 43 Posted October 23, 2006 It comes from a TU5J2, but the 1.4 XSi (TU3J2) and 1.6 (TU5J2) heads are the same. Share this post Link to post Share on other sites
Sam 4 Posted October 27, 2006 Ross: I may also have a gearbox you may be interested in. I have a BE4R box, low mileage but it has the mount snapped off (easily tigged back on) and also a low ratio hybrid BE1 1.9 box with Mi CWP. I was planning on mixing the two and using it for my new engine build. You could have both boxes for 80. Miles was going to combine the two boxes and fix the casing for me. Share this post Link to post Share on other sites
Sandy 189 Posted October 27, 2006 If not, i'll have them Sam Share this post Link to post Share on other sites
RossD 43 Posted October 27, 2006 (edited) Ross: I may also have a gearbox you may be interested in. I have a BE4R box, low mileage but it has the mount snapped off (easily tigged back on) and also a low ratio hybrid BE1 1.9 box with Mi CWP. I was planning on mixing the two and using it for my new engine build. You could have both boxes for 80. Miles was going to combine the two boxes and fix the casing for me. I dont think I can justify the cost at the moment Sam, sorry, I'll have to let Sandy have them! Thanks for the offer anyway! Just as a quick sidenote, does anybody know what the most powerful 8 valve 1.4 N/A engine is out there? (TU or otherwise!) The guy with the 137bhp AX must be pretty close.... Edited October 27, 2006 by RossD Share this post Link to post Share on other sites
rally ax 0 Posted October 27, 2006 I dont think I can justify the cost at the moment Sam, sorry, I'll have to let Sandy have them! Thanks for the offer anyway! Just as a quick sidenote, does anybody know what the most powerful 8 valve 1.4 N/A engine is out there? (TU or otherwise!) The guy with the 137bhp AX must be pretty close.... I don't know if I've got the most powerful, Pumaracing could get more ,but I really enjoy having such a WIDE powerband,,,it pulls SO well from just under 3500 and keeps going to the self imposed limit of 8150. It has over 80% of it torque available from 3500 and still has 90% of it at 8000rpm which makes it very easy to drive. Dave has worked out that he could fit bigger valves along with a different cam design and raise the power to at least 150bhp which would still keep it very tractable. 160+ was spoken about but taking a TU to 9500+rpm might prove to be a bit un-reliable !?. I would like to build a fresh bottom end given that this ones history is un-known (came in the boot of a car we bought) and we've been taking it to 8k all year on rallys and 7800 for the whole of last year doing hillclimbs and sprints Share this post Link to post Share on other sites
RossD 43 Posted October 27, 2006 I don't know if I've got the most powerful, Pumaracing could get more ,but I really enjoy having such a WIDE powerband,,,it pulls SO well from just under 3500 and keeps going to the self imposed limit of 8150.It has over 80% of it torque available from 3500 and still has 90% of it at 8000rpm which makes it very easy to drive. Dave has worked out that he could fit bigger valves along with a different cam design and raise the power to at least 150bhp which would still keep it very tractable. 160+ was spoken about but taking a TU to 9500+rpm might prove to be a bit un-reliable !?. I would like to build a fresh bottom end given that this ones history is un-known (came in the boot of a car we bought) and we've been taking it to 8k all year on rallys and 7800 for the whole of last year doing hillclimbs and sprints Blimey! Thats really what i want with my engine, good midrange, a good headline figure but not at the expense of a nice wide powerband. Just out of interest, would you mind describing your engine spec? What bodies are you running? Share this post Link to post Share on other sites
