Timing belt

[440Magnum]

Originally Posted By: Zedhed


Sorry friend, but those days are past, only a few domestic engines are still push-rod engines that use the short timing chains. Most are now SOHC or DOHC and use long timing chains up to the cams. Ford V-8s and V-6s and I-4s do, Chrylser V-6s and I-4s do, GM V-6s, some V-8s and I-4/5/6s all use long timing chains.

The days of push-rod engines are nearly finished, OHC engines, with timing belts and chains are the norm in 2010. Sorry, no more new 1958 Chevy's sold anymore -- time to upgrade our knowledge....


Nah, the days of pushrod engines will never be finished. There's too much to win on the small package size compared to the space wasted with OHC. And for most applications (anything that stays below 6000 RPM) there are minimal performance advantages to OHC.

Among the domestics I'll grant that here are more OHC engine families on the market than pushrod, but I'll wager that by sales *volume* there's less of a difference and pushrod may even be ahead. All GM v8s except the Northstar are pushrod and both of the Chrysler Hemis are pushrod. The GM 3.8 is pushrod. The Chrysler 3.3 and 3.8 v6 engines in all those minivans out there are pushrod. Very few truck diesels are OHC. Pushrod simplicity and reliability is going to be around for many more years.

 

[SteveSRT8]

X2, you are right on it.

With VVT systems and more fancy technology the ol' pushrod is here for a long time to come!

Beats me how an 'economical' car needs expensive services like TB replacement at only 60k.

 

[440Magnum]

Originally Posted By: SteveSRT8
X2, you are right on it.

With VVT systems and more fancy technology the ol' pushrod is here for a long time to come!

Beats me how an 'economical' car needs expensive services like TB replacement at only 60k.


Not looking forward to replacing the rubberband on wifey's PT Cruiser- that thing is *stuffed* in. I've never done one on a Honda transverse engine, but the PT looks about as bad. Changing it on the old LH car 3.5L v6 was only slightly less complicated than changing a fan belt- that was my idea of a perfect FWD engine installation (well, except for driving the front wheels....)

 

[mpvue]

Originally Posted By: Zedhed
Originally Posted By: mpvue
Originally Posted By: scurvy
Maybe the domestics are better at it, but I hear so many reports of 'chain slap' when cold (until the tensioners get full oil pressure) I'm leery of them even then.



short timing chains are the norm on pushrod domestics, but they are short, only connecting 2 gears.


Sorry friend, but those days are past, only a few domestic engines are still push-rod engines that use the short timing chains. Most are now SOHC or DOHC and use long timing chains up to the cams. Ford V-8s and V-6s and I-4s do, Chrylser V-6s and I-4s do, GM V-6s, some V-8s and I-4/5/6s all use long timing chains.

The days of push-rod engines are nearly finished, OHC engines, with timing belts and chains are the norm in 2010. Sorry, no more new 1958 Chevy's sold anymore -- time to upgrade our knowledge....

you didn't understand my post. I specified 'pushrod domestics' as having short timing chains. that is absolute truth. I did NOT say all domestics, just the pushrod variety.
as for upgrading my knowledge, perhaps you should be talking about yourself. the GM LS engine series of pushrod V8's are used in everything from escalades to pickups to the camaro and corvette. hardly "a few" and hardly "finished". the LS is one of the most amazing engines ever made.
the modern chrysler hemi is also a pushrod engine.
maybe YOU need to come into the 21st century.

 

[ekpolk]

I have to agree with the last. There's nothing inherently "wrong" with pushrod engines, except for one thing. That is, given the mechanical challenges, it's necessarily going to be harder to do full variable valve timing, intake and exhaust, with one cam nestled inside the block, and "communicating" with the valves via pushrods. Zedhead overlooks the one major, hugely major, and inescapable advantage of pushrod engines -- their compact dimensions compared to similar-displacement OHC engines. Of course, the double irony here is that the pushrod engines have survived most persistently in applications in which this is not especially critical (as in domestic pickups and SUVs...). But they also fit nicely into such vehicles as old-school GM sedans (e.g. Impala) and the Chrysler minivans too. And, oddly enough, not too long ago, Toyota designed a new racing V-8 engine that has, you guessed it, pushrods...

 

[mpvue]

Originally Posted By: ekpolk
And, oddly enough, not too long ago, Toyota designed a new racing V-8 engine that has, you guessed it, pushrods...

just for NASCAR; they HAD to; rules dictate a 358ci OHV V8 configuration. so they were allowed to build a clean sheet engine.
this actually benefited Chevrolet as well. up to that time, they were using production-based designs, but when they saw what toyota did, they did the same and came up w/ the NASCAR-specific R07 (IIRC the name).

 

[rjundi]

Originally Posted By: SteveSRT8

Beats me how an 'economical' car needs expensive services like TB replacement at only 60k.


Which car make is that? The typical interval is 8yrs/105k in the last 10 years.

 

[jcwit]

KIA Rio's timing belt is to be changed at 60,000 miles.

 

[marcre]

Originally Posted By: jcwit
KIA Rio's timing belt is to be changed at 60,000 miles.


That's the kind of thing that made me make this thread. If I was shopping for a new car, I would pass on something like that. To me, that is way too early to have to spend a large amount of money on a car for maintenance.

 

[andyd]

Mebbe I missed it ,but how bad is the TB to change? 60 K is the interval on my 22 yr car. I DIM so it isnt too bad.

 

[marcre]

To me it's different on an older car. For a car made in 2010, I think 60k intervals are crazy.

 

[jcwit]

Originally Posted By: marcre
Originally Posted By: jcwit
KIA Rio's timing belt is to be changed at 60,000 miles.


That's the kind of thing that made me make this thread. If I was shopping for a new car, I would pass on something like that. To me, that is way too early to have to spend a large amount of money on a car for maintenance.


I guess it depends on what you consider a large amount of money, and how much was spent on the car when purchased. Purchased my Kia at 2 years old for $3000, when it came time for timing belt my mechanic charged me $150, I supplied the belt for around $40. I don't consider $190 a large amount of money, but that depends on the individual I suppose.

 

[marcre]

I wouldn't consider that a large amount, but vehicles I've looked at had a higher cost.

I had a 99 Eclipse and a 99 Rodeo that I decided to sell/trade in when the time came. I sold the Eclipse and bought the Rodeo. I traded the Rodeo for my current Jetta.

Both the Eclipse and the Rodeo I got quotes for several hundred each at the time. Now, I count the belt, tensioner and water pump in both. Both vehicles were recommended to do all at the same time.

The Eclipse was recommended at 60k and the Rodeo at 90k.

 

[SteveSRT8]

60K miles is a disturbingly common interval for a LOT of cars.

Just so the owner knows it's coming...