6 replies to this topic

[Daniel_moody25]

Thinking of rebuilding my engine engine at some point once I've saved up the money and got the time, but I've got some questions as I've never rebuild a mini engine before but I've done quite a few other more modern engines at college. Right the reason I want to do a rebuild is cause the car has done 140,000 miles and the engine seems to use a bit of oil and I haven't got and leaks on the outside that I can see, so I'm assuming that either the piston rings are worn or some oils leaking in somewhere in the head. Would I just be able to get away with striping the engine cleaning everything, fitting new piston rings, crank bearings, big end bearings, thrust bearings and get a engine block gasket kit and head gasket kit with all the top hats and everything, while the head is off lap the valves. Would I get away with changing all of this or would I need to get the head skimmed and block rebored and have to fit oversized pistons.

Any help would be greatly appreciated

Thanks Dan

[Gremlin]

It depends how worn it is, initially strip it down and measure everything, determine whether honing out the bores and putting in new rings would be acceptable but yes, potentially not a lot of work, would be worth getting valve guides replaced as they're only cheap and it is bound to help with you oil consumption unless done recently (doesn't sound like it)

[Daniel_moody25]

Well I don't think it's worn too bad as the engine sounds pretty sweet the horsepower is kinda low though, was on the rollers in feb and with a full stage one I'm getting 46BHP so 1 more than standard so if I rebuild I'm assuming I'll get that BHP up. I'm not loosing too much oil, I changed the oil a week before L2B and I checked it the other day and it's gone just below the min line on the dipstick. The valve guides are they something I would be able to do myself or something that I would have to get someone else to do.

[Daniel_moody25]

Bump

[The Matt]

Valve guides are not really a home job.

You need to strip out the valves, press out the old guides,press in the new ones to a set depth and then ream them to the correct size.

[Guess-Works.com]

and then re-cut the valve seats, if you don't it will prematurely wear your guides if your seats are not centralised to the guide.

[wile e coyote]

It depends how worn it is, initially strip it down and measure everything, determine whether honing out the bores and putting in new rings would be acceptable but yes, potentially not a lot of work, would be worth getting valve guides replaced as they're only cheap and it is bound to help with you oil consumption unless done recently (doesn't sound like it)

 

This ....  A 998 at 140K is doing exceptionally well to produce 46 horses - even with a stage 1 kit on so much so that I suspect that its possibly not the original engine or it's previously been rebuilt....first job is to have a good squint at exactly what you've got and go from there.....having said that  - if its running sweetly, producing decent 'ish power and not using alarming amounts of oil.........stick with it!