hurbie Posted October 30, 2022 Share Posted October 30, 2022 hello all , just a short question , can you convert a 2.5NA diesel engine to be a 2.5 petrol ? reason for asking , i have 2 diesel lumps lying around, and 2.5 petrol engine's getting rare (and expensive) , i might as well turn these in to something usefull. gerben Quote Link to comment Share on other sites More sharing options...
miketomcat Posted October 30, 2022 Share Posted October 30, 2022 I would imagine it'll need petrol pistons and head at the very least, cam as well I suspect. Mike Quote Link to comment Share on other sites More sharing options...
smallfry Posted October 30, 2022 Share Posted October 30, 2022 Short answer is yes. As Mike says, pistons definitely, but ISTR the camshaft is the same though. Need the distributor, inlet manifold and carburettor. Here in UK, the price of diesel fuel is creeping up, but petrol price is coming down, so from that point of view its a good idea, and the petrol engine is much nicer. Quote Link to comment Share on other sites More sharing options...
steve b Posted October 30, 2022 Share Posted October 30, 2022 What about the timing gear drive?? Steve Quote Link to comment Share on other sites More sharing options...
smallfry Posted October 30, 2022 Share Posted October 30, 2022 18 minutes ago, steve b said: What about the timing gear drive?? Steve Actually yes. Its always the minor details that get you. The whole front end is different, so unless you have easy access to the parts, its a non starter. Quote Link to comment Share on other sites More sharing options...
Daan Posted October 30, 2022 Share Posted October 30, 2022 Yes, I build one myself, combining a 2.5 TD with a 2.25 3 bearing petrol. I used new 2.5 petrol pistons, that fit to the 2.25 conrods. The head fits, but I fitted 2.5 petrol valves which I think are larger, with unleaded valve seats pressed into the head, after having them counterbored. I also had the head skimmed by quite a bit, the total compression ratio was 9:1. The 2.25 camshaft drive chain works, you just need to pull a core plug out of the oil gallery so the tensioner has oil pressure. I fitted a 2.5 inlet manifold with a weber 2 stage carburettor, and was running it on LPG. the distributor and fuel pump of the 2.25 fitted. Went very well. Daan 3 Quote Link to comment Share on other sites More sharing options...
hurbie Posted November 1, 2022 Author Share Posted November 1, 2022 thanks for the reply's . so bassicly i need a good 2.25 petrol for parts ...and some spare time .... Quote Link to comment Share on other sites More sharing options...
smallfry Posted November 1, 2022 Share Posted November 1, 2022 2 hours ago, hurbie said: so basically I need a good 2.25 petrol for parts ...and some spare time .... And a gasket set. Quote Link to comment Share on other sites More sharing options...
miketomcat Posted November 2, 2022 Share Posted November 2, 2022 11 hours ago, hurbie said: thanks for the replay's . so bassicly i need a good 2.25 petrol for parts ...and some spare time .... Not necessarily good, one with a knackered bottom end would work. Mike Quote Link to comment Share on other sites More sharing options...
Daan Posted November 2, 2022 Share Posted November 2, 2022 4 hours ago, miketomcat said: Not necessarily good, one with a knackered bottom end would work. Mike I had a completely finished 2.25 which I rebuild using the 2.5 block and crank basically. It Just meant my land rover would be off the road shorter, as I could get the block done first, then pull the 2.25 apart and mount the parts to this 2.5 block. I do remember the 2.5 petrol pistons had a limited amount of over sizes available, so check this before you get the block bored, if this is the plan. If you decide to go ahead with this build, I can give you all the details for this even in Nederlands, but it was about 26 years ago, and my memory is not getting any better! Daan 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.