Strength of the 2.7 vs 2.5 bottomend?

[Chuckcruzin1986]

I blew two 2.7 engines in 2 weeks! Is it bad luck or should I be running 2.5 bottomends. I have not taken them apart but they both had over 200,000 miles and it was not the timing belt (new) but it seems like the main bearings.

The real question is: Strength of the 2.7 vs the 2.5...are they the same main bearings etc.???

Ideas?

Thanks
Chuck

[asubimmer]

you need to learn how to drive...

[E30_fiend]

you need to learn how to drive...

quoted for truth

[jlevie]

Other than the crank shaft, a 2.7 and 2.5 block are the same.

I suspect that the main problem is the 200k on the short blocks and wear on the bearings. If not totally destroyed, check the crank on one of these for wear and rebuild the bottom end.

[Jordan325iC]

You're just unlucky. There is no information at all that suggests that 2.7 bottom ends are any weaker than 2.5 bottom ends.

[5KWattson]

you need to learn how to drive...

+2

[mikegar]

5kwatson needs to learn how to drive too cause his shit blew up too...

[slow e30]

Yeah, its not the engines dude, its you. learn to drive the car.

[Chuckcruzin1986]

Learning to drive.......please help

I am ready to learn how to drive. Would someone step forward and guide me as to what to do? Should I keep the revs under 2000? Warm the engine for 2 hours before bringing above 2000? Maybe if I had an automatic trans it would help. Maybe I should hire a driver. Change the oil every 1000 miles? Remove my synthetic oil?
Ideas please?



Thanks,
Chuck

[slo325i]

I blew two 2.7 engines in 2 weeks! Is it bad luck or should I be running 2.5 bottomends. I have not taken them apart but they both had over 200,000 miles and it was not the timing belt (new) but it seems like the main bearings.

The real question is: Strength of the 2.7 vs the 2.5...are they the same main bearings etc.???

Ideas?

Thanks
Chuck

I would have at least done the piston rings and rod bearings while the engine's out. When the block was on my stand, front/ rear main seals;piston rings/rod bearings were done in like an hour?? Bad idea to put in a motor that you have no idea of. Could have at least pulled the oil pan and check if there were any play in the rods...

Justin

[416stroker]

Whats up with all of the new retards. That ask questions and get there answers and feel the need to be smart ass pricks? ITs your driving 2.7 are tough my 2.7i took a beating
and it was a juckyard shortblock

[Chuckcruzin1986]

I think this is the best advice

I would have at least done the piston rings and rod bearings while the engine's out. When the block was on my stand, front/ rear main seals;piston rings/rod bearings were done in like an hour?? Bad idea to put in a motor that you have no idea of. Could have at least pulled the oil pan and check if there were any play in the rods...

Justin

I am going to tear down one of the engines and build it as you have recommended. No more installing used engines.
Thanks
Chuck

[jlevie]

If the crank shaft doesn't have score marks, you need to measure each journal to check for wear before fitting new bearings. That is several measurements with a micrometer around and across each journal. If worn, the crank can be re-ground and over sized bearings used.

[nando]

I turn my 2.7 crank past 7000rpm on a daily basis

being junkyard engines they may have already been dead when you got them, or very well near it. crank/rod bearing problems are pretty uncommon on the M20.

[StereoInstaller1]

I turn my 2.7 crank past 7000rpm on a daily basis

being junkyard engines they may have already been dead when you got them, or very well near it. crank/rod bearing problems are pretty uncommon on the M20.

I was thinking the same thing. A quick survey would show just how reliable the M20 bottom end is.

I think the OP just has bad luck!