Internals - weak spots

R

rongkeys

Lifer
Looking for some info with regards to the 4e fte internal weaknesses after I've taken to engines apart one bought as a spare engine and the other running but light bottom end rattle apx 2k rpm.
both of which have picked up on the '3rd cylinder' crank. one engine had spun a bearing (the spares one) and bent a con rod which scored the bore. the running engine also had a bent con rod.

Dose this suggest that the Rods & shell bearings are the weak components?

I ask as I will be rebuilding one engine to refit into my project car with an aim for at least 200 ATW. So would be a good opportunity to Strengthen. Any suggestions on this or recommendations on parts used and that worked I.e from personal experience


thanks
 
Fatman

Fatman

Member +
Pistons crack ring lands between compression rings with any sort of detonation, they are far and away the weakest link. There are two types of rods available in 4e-fte's, big and small. Big came on the earlier engines, small on the later EP91+ engines. The big rods are very capable.

Bearing issues almost always stem from oil issues, there are no inherent weak spots in the bottom end but they don't respond well to any level of oil starvation. You'll notice discolouration from overheating on number 4 usually, sometimes scoring on the cams at that end of things too if the engine has been run low or surging.

Personally I would replace the pistons with a slightly higher static compression 74.5mm forged slug of a reputable brand, shot peened/destressed 'big' rods and all OEM bearings/seals etc through the bottom end. Weld in a baffle plate to the sump if you're planning on any decent cornering. Ensure you retain the harmonic balancer crank pulley and always a good idea to balance the whole rotating assembly (e.g flywheel/clutch as well)
 
R

rongkeys

Lifer
Thanks for info, well so far from the 2 engines I've stripped I have
Good/useable
8 pistons
2 thin rods
2 thick rods
2 heads complete

I'm not looking achieve mega power or to spend big money.

I have notice TM DEV do a piston rod combo including arp bolts so maybe the best option?
 
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