Engine weakness

[Tiapan]

I thought i would start this thread to share differant findings or popular knowledge about differant engines and there factory weaknesses, when modded or not, its interesting to know and is also great pub ammo

may also help correct many beliefs or rumours

ill start...

Boss 5.4's sintered metal oil pump gears, fail with high rpm or hp, need billet oilpump gears

Nissan SR20, rocker arms jump off the lifter in high rpm applications, need to use rocker arm stoppers

Cleveland, oiling system can starve the bottom end, can be corrected with oil restrictor kit,
core shift in many blocks

Windsor 302 - prone to splitting due to thin webbing, aftermarket blocks have corrected this.

Boxer - cracking piston skirts in stock application when being thrashed in cool weather

Holden v8- might be quicker to list the pro's? lifter bore alighnment to cam, always on the , needs brass lifter bores installed

Holden 202- Shreading cam gear when pushed too hard

ill add more later, see what you can thing of

[Falc'man]

Here's info on the ticking problems with the pre '05 Boss.

[CAMS290]

Originally Posted by Tiapan

Holden v8- might be quicker to list the pro's? lifter bore alighnment to cam, always on the , needs brass lifter bores installed

Punching pushrods through rocker arms, wearing camshafts out because of lack of oil on lobes, factory single row timing chains stretching or even breaking.

[66 coupe]

thats only when they have oil pressure, usually the pickup is all sludged up = no oil pressure

[yift]

5.4 boss motors prone to ovaling bores.

[Dezza]

3.9/4.0 litre straight 6, particularly in EA-EL - prone to blowing headgaskets - Everyone know EAs blow them, but not everyone know EB-ELs are just as bad for it.

[Bluehoon]

BA XR6T - Rods & Valve Springs. Prone to throw the leg when pushed.


VN-VR Buick 6 - dare comment?

[bcr2734]

Originally Posted by Dezza!

3.9/4.0 litre straight 6, particularly in EA-EL - prone to blowing headgaskets - Everyone know EAs blow them, but not everyone know EB-ELs are just as bad for it.

yes they do, Every mechanic i know does aswell as do the owners.

[Dezza]

Originally Posted by bcr2734

yes they do, Every mechanic i know does aswell as do the owners.

But the consensus I get from some people is that EAs blow head gaskets every few 1000kms but EBs are perfect. I know most know the real story, but some don't and are just oblivious to the fact they're pretty much the same engine.

[yift]

dezza they are bad ea-bf. ba/bf not as bad but still prone. no ford ohc motor is safe from this kind of weakness.

[stevepet]

Nissan TB42 prone to cracking heads especially if using LPG.

[Mr Hardware]

Originally Posted by yift

dezza they are bad ea-bf. ba/bf not as bad but still prone. no ford ohc motor is safe from this kind of weakness.

Yeah I don't think so mate. I looked after a fleet of cabs and we never, ever took a head off an AU. Each of the 20 odd cabs did half a mil each while i looked after them too. The AU head gasket is a steel one as opposed to the paper one found on the e-series. The reason they blow is because of an iron block and alloy head, and the steel head gasket avoids this problem.

[CAT600]

Originally Posted by yift

5.4 boss motors prone to ovaling bores.

Got a link?

Never heard of that one before, Cast Iron modular blocks are usable up to 1200rwhp without issue. The only thing that kills a 5.4L mod block is the connecting rod coming through the side with factory sintered rods at 6500rpm+

Daniel

[CAT600]

Originally Posted by yift

dezza they are bad ea-bf. ba/bf not as bad but still prone. no ford ohc motor is safe from this kind of weakness.

There are 600+ rwkw XR6T/F6's out there using stock heads/head bolts and blocks. There are 400+ rwkw ones still using stock head gaskets as well.

Daniel

[nugget378]

Originally Posted by Tiapan

Cleveland, oiling system can starve the bottom end, can be corrected with oil restrictor kit,
core shift in many blocks

The biggest issue with a cleveland is getting the valvtrain/geometry correct for any high rpm work, by far the most common cause of breakages, IMO the oiling issues are over rated, and easily fixed with a well designed sump..

[Windsor220]

Originally Posted by Dezza!

3.9/4.0 litre straight 6, particularly in EA-EL - prone to blowing headgaskets - Everyone know EAs blow them, but not everyone know EB-ELs are just as bad for it.

I thought EF-ELs were the worst actually.

[madmelon]

The Holden/Buick 3.8's tend to stretch timing chains over time (more than most cars anyway), causing the cam timing to get progressively worse. Results in poor performance and economy. Can't recall the source of this information.

[Bossxr8]

Holden 3.8 V6's tend to be so rough they cause brain damage to their drivers.

[CAT600]

Originally Posted by Bossxr8

Holden 3.8 V6's tend to be so rough they cause brain damage to their drivers.

Holden Ecotec's tend to be rough, Their drivers are brain damaged.............

Thats a paradox :

[Mr Hardware]

Originally Posted by Bossxr8

Holden 3.8 V6's tend to be so rough they cause brain damage to their drivers.

I hate the holden slagging but this one made me mega LOL

[BJ]

Originally Posted by nugget378

The biggest issue with a cleveland is getting the valvtrain/geometry correct for any high rpm work, by far the most common cause of breakages, IMO the oiling issues are over rated, and easily fixed with a well designed sump..

Yep i'll second that one Tony.

[needaXYGT]

I thought EF-ELs were the worst actually.

EA-EL all the same!

[yift]

Originally Posted by Mr Hardware

Yeah I don't think so mate. I looked after a fleet of cabs and we never, ever took a head off an AU. Each of the 20 odd cabs did half a mil each while i looked after them too. The AU head gasket is a steel one as opposed to the paper one found on the e-series. The reason they blow is because of an iron block and alloy head, and the steel head gasket avoids this problem.

how often do cabs sit around switched off for more than 3 hours? head gaskets on these sixes blow because of the cooling off diferences between iron and aluminium. steel gaskets do help but cabs should never be competed with private vehicles or used as a real world example. i have seen taxi autos last 300,000+ km before needing replacement whereas a 4speeder in a private car like mine or yours may only last 150,000km. i have done a few headgaskets on the ohc motorsea - el are by far the worst but like i said no ohc motor is safe.

[Dezza]

Originally Posted by Torxteer

I thought EF-ELs were the worst actually.

True. My uncle's EL did about 3 of them, and it's done roughly as many kms as my EA which has only done one.

[yift]

Originally Posted by CAT600

Got a link?

Never heard of that one before, Cast Iron modular blocks are usable up to 1200rwhp without issue. The only thing that kills a 5.4L mod block is the connecting rod coming through the side with factory sintered rods at 6500rpm+

Daniel

that was an issue with the early 5.4's when ford did a recall for supposed piston rings. no links for this info, just a ford engineer who i know.

[yift]

Originally Posted by CAT600

There are 600+ rwkw XR6T/F6's out there using stock heads/head bolts and blocks. There are 400+ rwkw ones still using stock head gaskets as well.

Daniel

like i said ba/bf not as bad but still prone.

another thing i forgot to mention was early barra sixes cracked their blocks too. most ford dealers, that had these failures come through, thought it was a headgasket problem when infact is was cracked blocks. it had something to do with the casting of the early blocks from memory but cant remeber 100%.

[yift]

mitsubishi v6: burn valves, wear lifters
mitsubishi magna 2.6 astron motors: timing chain stretches (bloody noisey)
toyota 4 cyl motors: carboning of oil internally in the motor.
daewoo motors: same as above, chew out cam lobes
ford laser kc ke/mazda 323 same era: head gasket, cam bearings
chrysler motors:
ls1: piston slap from early motors due to poor casting
pre ecotec v6 motors: what isnt wrong with them
ecotec motors: as above but improved
alloytech motor: same as above but worse and less power, stretch timing chains especially in the VE commodore.

[CAT600]

Originally Posted by yift

that was an issue with the early 5.4's when ford did a recall for supposed piston rings. no links for this info, just a ford engineer who i know.

If there was ever an ovality issue with 5.4L blocks, I have never read about it, and it would be an issue that was present when the block was machined from new....... those blocks just dont give any trouble at all.

If you said piston ring pack issue, well, we all know that the early 290 engines had a problem with the combination of Mobil 1 and FPV's ring pack choice.

Daniel

[svo347]

Originally Posted by nugget378

IMO the oiling issues are over rated, and easily fixed with a well designed sump..

Im sure im goin to get trampled here but i thought the idea with Clevo oiling systems was to add a restrictor kit to limit the volume of oil pumped into the heads at high rpm and the oils slow return to the sump. I remember seeing breathers extended up fairly high in a mates sprint car engine as everytime he went around the track, oil used to spew from the right hand r/cover, restrictor kit fitted and it was all good

[CAT600]

Originally Posted by svo347

Im sure im goin to get trampled here but i thought the idea with Clevo oiling systems was to add a restrictor kit to limit the volume of oil pumped into the heads at high rpm and the oils slow return to the sump. I remember seeing breathers extended up fairly high in a mates sprint car engine as everytime he went around the track, oil used to spew from the right hand r/cover, restrictor kit fitted and it was all good

I can only assume that the bigger and better baffled sump must prevent oil starvation due mainly to the extra volume?

Daniel