OWL Posted September 9, 2007 Share Posted September 9, 2007 Hello All I am current restoring a 1961 Series 2a Project which I bought a couple of years ago, I'm just about to start looking at the engine and did a compression test today and the results from the fan backwards are 120, 95, 95 & 30 psi. I want to keep the engine and wondered :- 1) What should the compression be? 2) What may be causing the low reading on the last cylinder 3) Whist I have the engine out and on an engine stand what else is worth doing to it before it goes back in , e.g. Electronic Iginition or Megajolt, complete refurb etc. etc. Thanks OWL Quote Link to comment Share on other sites More sharing options...
Les Henson Posted September 9, 2007 Share Posted September 9, 2007 I take it you are talking about a 2.25 Petrol? If it was diesel lump - the compression would be seriously pants . 120 is ok for a fairly worn engine, but 95 and obvioulsy 30 are not good. Fortunately you can get a complete set of pistons with rings and gudgeon pins for £100, so no big expense. What sort of compression test was it, just a dry spin? To determine if it's bores or valves you need to do a wet test as well. Put a small amount of oil in each bore and do the test again. If there's a significant rise in the results, you have worn bores or stuck rings. If the test is much the same then it's down to the valves (of course you could have head gasket problems). Les. Quote Link to comment Share on other sites More sharing options...
OWL Posted September 9, 2007 Author Share Posted September 9, 2007 I take it you are talking about a 2.25 Petrol? If it was diesel lump - the compression would be seriously pants . 120 is ok for a fairly worn engine, but 95 and obvioulsy 30 are not good. Fortunately you can get a complete set of pistons with rings and gudgeon pins for £100, so no big expense. What sort of compression test was it, just a dry spin? To determine if it's bores or valves you need to do a wet test as well. Put a small amount of oil in each bore and do the test again. If there's a significant rise in the results, you have worn bores or stuck rings. If the test is much the same then it's down to the valves (of course you could have head gasket problems). Les. Les Its a Petrol I removed all the plugs, gave each cylinder a couple of shots of oil and then turned the engine over for 5 or 6 revolutions on the starter. Thanks Quote Link to comment Share on other sites More sharing options...
Les Henson Posted September 9, 2007 Share Posted September 9, 2007 You should have done the test dry and then wet to get a more definite result. It sounds like you will have to whip the head off anyway. If it's a project, then reseating the valves etc is a matter of course. To measure bores for wear or ovality you need one of these:- For measuring of bore diameter and groove width. The spring-loaded plunger expands within the hole. Knurled locking screw allows plunger contacts to be held in position, removed and measured with a micrometer. Les. Quote Link to comment Share on other sites More sharing options...
OWL Posted September 9, 2007 Author Share Posted September 9, 2007 You should have done the test dry and then wet to get a more definite result. It sounds like you will have to whip the head off anyway. If it's a project, then reseating the valves etc is a matter of course.To measure bores for wear or ovality you need one of these:- For measuring of bore diameter and groove width. The spring-loaded plunger expands within the hole. Knurled locking screw allows plunger contacts to be held in position, removed and measured with a micrometer. Les. Thanks Les What improvement will a high compression head give and is it worth the money ? Quote Link to comment Share on other sites More sharing options...
Les Henson Posted September 9, 2007 Share Posted September 9, 2007 I don't know to be honest. There are more knowledgeable people on here about that sort of thing. Les. Quote Link to comment Share on other sites More sharing options...
Jon White Posted September 9, 2007 Share Posted September 9, 2007 To be honest i wouldnt bother spending money rebuilding a 2.25 petrol. Look out for a 2.5 petrol from a defender instead. Externally they're identical, all the ancilliaries will swap straight accross, and people cant give away 2.5 petrol engines these days. I picked up 2 for free a couple of years back. Its a nuts and bolts job to swap them over - its what i did when I blew up the origional 2.25 that was in my series! Jon Quote Link to comment Share on other sites More sharing options...
OWL Posted September 9, 2007 Author Share Posted September 9, 2007 Jon whats the 2.5 performance like in comparison to 2.25 Cheers OWL Quote Link to comment Share on other sites More sharing options...
Jon White Posted September 10, 2007 Share Posted September 10, 2007 Frankly - not much - I think most people would be hard pushed to tell the difference - they're both pretty asthmatic! IIRC its supposed to have about 10Hp more or something, but its only something like 85BHP anyway which is pretty pants for a 2.5L engine really! Jon Quote Link to comment Share on other sites More sharing options...
edwardatherton Posted September 10, 2007 Share Posted September 10, 2007 Jonwhats the 2.5 performance like in comparison to 2.25 Cheers OWL I've just put a 2.5 in my S1 and it goes very well - it certainly feels more powerful than the 2.25 I had in my 86" years ago, but there isn't much difference between a well-sorted 2.25 and a 2.5. Be cheaper to put a 2.5 in and get unleaded 8:1 head as standard than spend the money doing the same to a 2.25. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 10, 2007 Share Posted September 10, 2007 Ain't no substitute for (a very small amount of) cubes Agreed little point tweaking a knackered 2.25, mind you there's not much more point faffing with a 2.5 when V8's are so cheap. Quote Link to comment Share on other sites More sharing options...
Jon White Posted September 10, 2007 Share Posted September 10, 2007 Agreed, but a 2.5 is a nuts and bolts swap that doesnt require anything else to be changed to fit it. Fitting a V8 is alot more involved......... Quote Link to comment Share on other sites More sharing options...
OWL Posted September 10, 2007 Author Share Posted September 10, 2007 So the options seem to be :- 1) Sort out the 2.25 Petrol, but sounds like throwing good money down the drain 2) 2.5 Petrol or 2.5 NA Diesel 4) 200Tdi As all these will bolt straight on the 2a Chassis or is there any other options ? So whats the best option and any recomendations where to get a good one ? Cheers Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 10, 2007 Share Posted September 10, 2007 The search button (and tech archive) are your friends - the options you mention have been done to death many times before. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted September 11, 2007 Share Posted September 11, 2007 If you are only looking for reliability with a small power increase with minimal spanner work, then I'd suggest a 2.5 N/A diesel. This engine is almost indestructible. Les. Quote Link to comment Share on other sites More sharing options...
Jon White Posted September 11, 2007 Share Posted September 11, 2007 Depedns how much work you want. 2.5 petrol is a simple nuts and bolts job with no fabrication required. 200Tdi will fit, and bolting it in is the easy bit, but all the plumbing, mounting of intercoolers etc etc is a load more hassle. I'm just in the process of fitting a Disco 200Tdi into mine having just removed a V8. A disco 200 will bolt straight onto the series engine mounts, but the exhaust etc is more difficult to make. A defedner 200 will requrie engine mounts fabricating, but the exhaust is alot easier. Disco engines are a lot cheaper than defedner ones are. Jon Quote Link to comment Share on other sites More sharing options...
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