Who Thinks OHCs are a good idea for V engines?

[ShotGun429]

QouteIf you think that's bad, look at the Ford 4.0L SOHC Cologne V6s in the Explorer/Ranger - 3 separate chains, the engine needs to be pulled to access the right hand chain assemblies.) My 2002 Ranger 4x4 4.0L SOHC best truck Ive ever owned, 180,000 hard miles with NO Issues Ever! Great engine Overhead Cam is the way indeed. Or it may be the 15w40 oils i use since truck was new?

 

[Tomioka]

Originally Posted By: HerrStig
Shops around here do an I 4 Camry belt, water pump and cam seals for 350 bucks, not 1000.


My 01 Tundra V8 wants to talk to you then. ~$1000 just so the pistons don't crash into the valves because the 2UZ-FE engine is an interference design. Plus the thread is talking about V engines not inline engines.

At least I don't have to worry about long chains or belt in the 02 Silverado. IMO cam in block chains are true timing chain engines.

 

[ARB1977]

Neglect is what kills chain drive engines. Keep that oil changed.

 

[ShotGun429]

Originally Posted By: ARB1977
Neglect is what kills chain drive engines. Keep that oil changed.
+100 percent

 

[splinter]

That independently variable valve timing tuning flexibility is pretty useful with a DOHC configuration.

Belated SBC to LS acceptance is quite enough progress for me to date, thanks.

 

[SteveSRT8]

Originally Posted By: Silverado12
Originally Posted By: SteveSRT8
Simplicity always wins for me. Long term driving experience showed me that less complex has fewer parts and is far less likely to fail, all other things being equal. Power density is very equal these days with forced induction. All of my sons drag racing buds use large single/dual turbos on LS based engines. Win a lot. There are other very hot makes there too but you can create a very quick car very cheaply with LS engines.

Look around on the net you'll find some extremely potent pushrod mills...


Not only that but a lot of the LS guys do it with a junkyard engine. I will say that the 1998 Mustang I had was super quiet with almost 170,000 miles. Timing chain seemed ok.


Yep, the TC works well in a pushrod mill. Short, simple, well oiled. And many current pushrod V8's move the cam timing, too, so you get most of the benefits that two independently variable cams give you. Lots of ordinary folks not familiar with OHC design think OHC V8's have 2 cams, not 4.

I can't imagine any real motorhead not feeling that OHC is the way to go, but IMO the very small difference in power output is not worth the extra expense and complexity.

 

[Trav]

Yep lots of V8 DOHC out there. Check the chains on this 4.2 Audi and the gear drive on a DOHC Oldsmobile W43 V8. Ford was doing similar gear drive stuff with their small blocks. I think it was a matter of cost but it would be great if they brought this back, no chains, no belt, zero timing variation due to chain stretch and component wear.

 

[SwampSurvivor]

I do like gear drive. Ford did that on their 300I6 up until they stopped making it. But they had to switch to nylon gears because the steel gears were too noisey apparently.

The timing setup on GM's 3.6 is also pretty crazy.

 

[OVERKILL]

Originally Posted By: Trav
Ford was doing similar gear drive stuff with their small blocks.


Ford had a couple of different setups, including probably their most well known SOHC big block V8, the "Cammer", which was the inspiration for the Hurricane engine, which became the current 6.2L in the Raptor.

The Indy Cammer (255) was a destroked SBF IIRC, with a gear-driven 4-cam setup.






The 427 SOHC had a pretty decent following back in the day. There were lots of modifications to make it gear and belt driven.

 

[Ducked]

Originally Posted By: ARB1977
Neglect is what kills chain drive engines. Keep that oil changed.


I've had one Ford DOHC Sierra (European) break its plastic chain guide. Doubt oil quality had much to do with that.

Call me old-fashioned but I feel making critical, stressed, inaccessible engine parts out of something that looks similar to bakelite is bad behaviour and should not be encouraged, so I'd try and avoid buying another like it.

 

[Trav]

I don't see that double row chain on the 427 failing early either. It takes up some real estate up front but the additional reliability and durability would be well worth it.
When you think about it, the US manufacturers have hit rock bottom (maybe), looking at what Olds, Buick, Pontiac, Ford had in the works for engines was amazing and far ahead of their time, the entry level Chevy had the runt of the litter and that's we we are saddled with today as a performance engine while the rest of the world had moved on and GM threw the good stuff in the trash.

Not that the Chevy V8 are bad engines they are durable enough its just they are low tech primitive lumps rehashed, the lowest engine on the food chain at GM. Unlike most enthusiast I have no affection for them at all, when you consider they brag about a 600 HP new GM engine and the OW43 had 700 HP in 1969. that's HellCat teritory. The closest thing GM has come to anything really decent in recent decades is the North Star but they frigged that up releasing it before it was perfected. Check out what Pontiac had on the board, the 389 and 421.

 

[demarpaint]

Originally Posted By: Miller88
I do like gear drive. Ford did that on their 300I6 up until they stopped making it. But they had to switch to nylon gears because the steel gears were too noisey apparently.



That Ford set up was great.

 

[andyd]

Overkill, the last picture of the belt driven 427 BBF is the best looking solution to me. Trav, Don't get me started on SBCs being the generic hot rod engine. So many vintage cars ruined by a Chevelle sub frame. I've seen SBCs on everything that ever used an engine.

 

[JTK]

I would imagine it's a lot more than 3ft worth of chain in your average OHV V-style or flat engine. It does look daunting and is a big deal should their be a chain failure, but these engines are living as long as the vehicle's they're in for the most part. You do see issues here and there, but it's not much.

 

[DoubleWasp]

Originally Posted By: Fsharp
Originally Posted By: IndyIan

I suspect an OHC engine is slightly easier to get good efficiency out of as well, otherwise somebody would use an 4 cyl OHV motor in a regular car.


I've often wondered why GM doesn't do this. They could use the same head design as their LT engines. There 5.3 makes 355 horsepower so a 2.65 liter 4 made from half of it would be about 178hp. They could even make a 210hp 3.1L, although it would need some balance shafts for sure!


The automotive rags would slaughter them for having a "low tech" engine.

The only reason why they have backed off of criticizing GM for using a pushrod engine in the current applications is because every time the rags predicted that a new-tech player was going to unseat the LS motor, it's either succeeded only in matching the LS, or failed miserably to compete.

Really hard to argue against sales numbers and reputation.

 

[IndyIan]

Originally Posted By: DoubleWasp
Originally Posted By: Fsharp
Originally Posted By: IndyIan

I suspect an OHC engine is slightly easier to get good efficiency out of as well, otherwise somebody would use an 4 cyl OHV motor in a regular car.


I've often wondered why GM doesn't do this. They could use the same head design as their LT engines. There 5.3 makes 355 horsepower so a 2.65 liter 4 made from half of it would be about 178hp. They could even make a 210hp 3.1L, although it would need some balance shafts for sure!


The automotive rags would slaughter them for having a "low tech" engine.

The only reason why they have backed off of criticizing GM for using a pushrod engine in the current applications is because every time the rags predicted that a new-tech player was going to unseat the LS motor, it's either succeeded only in matching the LS, or failed miserably to compete.

Really hard to argue against sales numbers and reputation.

My WAG is that 90%+ of people buying normal 4 cyl cars don't care anymore what's under the hood. 3/4 will probably look up the mileage to see if its reasonable, 1/2 may look at the hp, and the rest just take a quick spin and whatever the mechanicals are, find they are good enough.
Results are what counts in terms of efficiency with CAFE in place, so if a half a small block would increase efficiency even 1% in a Cruze, Chevy would probably do it. Dodge could've marketed half a Hemi pretty well in a Dart I think as well.

 

[nthach]

That Audi 4.2L V8 chain drive - read about it, it's brilliant(especially the auxillary accessory drive, just like an jet engine with a gearbox to drive the generator and hydraulic pumps) but also needlessly complex.

 

[Dave Sherman]

I sure hope the 3.6 in my Traverse holds up. It does not have a stellar reputation since the timing chains (3 of them) are known to stretch and require expensive repairs when they go. The weak timing chains were exacerbated by the fact the engine, transmission, and front cradle have to come out to replace them. There's a time lapse video on Youtube of what it takes to drop (not pull) the engine on a Traverse.

 

[SHOZ]

The DuraTec Ford motors were DOHCs with chain drive. I never had a problem with them even at +150k miles.

 

[Jarlaxle]

Originally Posted By: Ducked
Originally Posted By: ARB1977
Neglect is what kills chain drive engines. Keep that oil changed.


I've had one Ford DOHC Sierra (European) break its plastic chain guide. Doubt oil quality had much to do with that.

Call me old-fashioned but I feel making critical, stressed, inaccessible engine parts out of something that looks similar to bakelite is bad behaviour and should not be encouraged, so I'd try and avoid buying another like it.


Seemed to work fine for Honda...I recall their motorcycle chain guides were nylon as far back as the 80's. (Not sure...my wife's 80,000+ mile PC has given no reason to actually check.)