Ford = OHV

[Ze]

Packaging wise (which is 50% of current engine design) it's dumb.

Yes but from a balance perspective anything but a 90 degree V8 sucks. You'll get a heavier engine as you'll end up needing balance shafts. There is a reason why the vast majority of v8 designs are 90 degree V8's.

A DOHC engine is bigger than an equivalent displacement single OHC or pushrod engine, particularly in a V form. Assuming all are decent modern designs of course. The bigger engine is therefore less efficient in space utilisation, requiring a bigger engine bay to accomodate it and therefore requiring a bigger car which uses more materials and is heavier.

Tell me again which engine is most efficient for everyday transport use?

However you can use a smaller engine for the same power and get better fuel effiiency if you go to a DOHC design.

They don't need to have much of a size penalty. The problem with the boss motor is they chose a undersquare design instead of a oversquare design.

Honestly there is bugger all reason to go a OHV design over a SOHC and a DOHC isn't that much bigger if designed properly.

[Billzilla]

Bill, in a V configuration the twin cam is far bulkier. Perfect example with which I am very familiar is the Nissan VG30, single and twin cam versions, virtually the same block so its an ideal comparo.

As I've said 1.7 million farking times, if they bothered to do the head properly it wouldn't be that much larger than a rocker-type head.

[MRMOPARMAN]

Yes but from a balance perspective anything but a 90 degree V8 sucks. You'll get a heavier engine as you'll end up needing balance shafts. There is a reason why the vast majority of v8 designs are 90 degree V8's.

wasnt there a thread on this recently here that basically said the firing order had more to do with it than just being a 60 degree V engine??

302 windors dont use balancing shafts and they do alright. actually i heard from a bloke at ford that the 302 engine had the least warranty problems of all of fords engines.

balancing shafts really arent that much of a penalty anyways. heaps of modern day engines use balancing shafts. theres plenty of ways you can get around a few kilo's of balancing shaft

[Billzilla]

302 windors dont use balancing shafts and they do alright. actually i heard from a bloke at ford that the 302 engine had the least warranty problems of all of fords engines.

A 90° V8 with a 90° crank has (from memory) the lowest first and second order vibes of any engine, expect maybe a straight-six.
You'd need a really good reason to vary from 90° on a road-going V8.

[EfiOz]

Yes but from a balance perspective anything but a 90 degree V8 sucks. You'll get a heavier engine as you'll end up needing balance shafts. There is a reason why the vast majority of v8 designs are 90 degree V8's.

I don't know what the gravity's like on your planet but on mine a 60deg V8 (between the banks not firing order) balances just fine.

[Billzilla]

A pretty good article on engine balancing.

[Ze]

I don't know what the gravity's like on your planet but on mine a 60deg V8 (between the banks not firing order) balances just fine.

I don't know which planet you live on.

60deg V6's and V12's balance fine but not V8's.

302 windors dont use balancing shafts and they do alright. actually i heard from a bloke at ford that the 302 engine had the least warranty problems of all of fords engines.

That's because windsors are a 90 deg V8 just like the clevo's and just about every other V8 out there. There are only a few designs and they aren't popular that use anything other than a 90 deg angle for a V8.

[jmac]

ower per litre is great on paper, or for a racing category or engineering discussion, but for a commodity, if it does the job on less fuel, less manufacturing and running costs, then the level of technology should defer to the actual on road ability, not ability per litre. If someone loses a race, do you really think anyone cares if their engine was 20% smaller? Winning's winning (turrito knows best)

2 valve engines have serious potential as far as fuel efficiency and emissions go. Tumble isn't nearly as good (imho) as swirl for mixture motion and combustion quality (vs quantity over a wider rpm range, which multivalves do work better on. The gm v8, like it or not, is very good at end result, albeit not so per litre. Who gives a fuck really.

Bills on the money about 90 degree cranks and harmonics if anyone cares. Add to the fact there's (for any given rpm) less time between combustion phases, and it's altogether one of the smoothest _feeling_ engines out there.

This well designed head stuff - you need adequate oil drain back and venting as well for ohc, and on a v blocked engine that does add a little to space requirements too. not to mention support for the cams and to help better anchor a bulkier head. It all adds up. For racing, of _course_ ohc is the only thing worth mentioning in all categories save for where it's specifically prohibited.

but these are mass produced multi role engines.. Big big big difference. Whilst the gm v8s aren't a brilliant example of technology per se, they _are_ a reasonable example of an efficiently engineered package for a 2v engine. They could be stronger, and some things in them I'm not fond of (rods for one) but they work well in their intended role.

[EfiOz]

I don't know which planet you live on.

60deg V6's and V12's balance fine but not V8's.

That's because windsors are a 90 deg V8 just like the clevo's and just about every other V8 out there. There are only a few designs and they aren't popular that use anything other than a 90 deg angle for a V8.

I thought they're a 60deg V8 the same as is the small block chev family. I'm talking the angle between the banks not crankshaft orientation. You're referring to the difference between a cross plane (90deg) crank and a flat plane (180deg) crank.

I think you're getting firing orders mixed up with physical layout.

[TK]

^ spot on jmac.
Why overcomplicate things, blowing out the cost & size of the engine when simply adding more capacity will achieve the desired result for a production engine with less cost & a smaller physical size.
Not to mention durability issues, lotsa little parts & tiny oil galleries can go to shit quite quickly if not maintained regularly, ignoring the fact that any engine should have regular oil changes the fact is that many people don't bother any where near as often as they should - especially yanks.
A big V8 with less moving parts & less intricate oiling system will not clog up with muck like DOHC engines are prone to doing.
The biggest 3 killers of modern DOHC 16V engines are overheating, broken/slipped cam belt & issues from clogged oiling systems - all due to lack of maitenence.
A cam-in-block V8 eliminates timing belts & intricate oiling systems, cutting potential maitenence issues by 60%. (Ignoring the early LS1's thirst for oil & subsequent problems).

By no means a pretty or sophisticated solution, but very effective from a mass production veiwpoint.

TK

[TK]

EfiOz - windsor & SBC are both 90 degree V8's, bank angle & crank index angle, I'm not sure why you're convinced they're 60 deg, they are most certainly not.

TK

[Billzilla]

ower per litre is great on paper, or for a racing category or engineering discussion, but for a commodity, if it does the job on less fuel, less manufacturing and running costs, then the level of technology should defer to the actual on road ability, not ability per litre. If someone loses a race, do you really think anyone cares if their engine was 20% smaller? Winning's winning (turrito knows best)

I''ll have to disagree for racing, as the vast majority of classes have either a capacity and/or a rev limit. In those cases, a two-valve engine simply will not be able to beat a four-valve.
A good example or racing engine like that is the class I run in - The rules allow for an unrestricted two-valve or a heavily restricted four-valve, to try to keep them roughly in parity.
The four-valve costs a great deal less to build & run, and lasts a hell of a lot longer. It also make more power and has a wider useable power band. But yes, the head (Suzuki Swift Gti) is a lot larger than the old 3K Corolla we used to run.

And I'll also have to disagree about the emissions, as the pentroof chambers (with the Suzuki kidney variant as well) burn demonstrably cleaner than any two-valve chamber.

[jmac]

Er Bill - I _said_ that for racing the 2v is inferior or specifically that the multivalve is the only serious option. What I meant above is specifically about a holden vs ford street drag meet. In cases where the v8 gm powered car snots the ford, how important is the fact the ford has more valves? It's hardly a fair comparison (whatever the undertakings for the sake of parity) to compare a 1970s tech 2v with a more modern 4 valver. I recall speaking to a bloke at Northern Mini, Henry Draper (whose link to the suzi motor might be known to some) who raced a swift or two somewhere sometime. he mentioned his affection for that engine, at the time, but also noted that there wasn't a hell of a lot that could be done to dramatically increase performance without valve interfernce and other issues. based on what he said, it's possibly fair to say that the suzuki motor is something more akin to a developed engine from the get go. I can't think of a more apt comparison off the top of my head.

on the topic of chevy v8s - I think _maybe_ their indy car v8 was narrower than 90 degrees - but buggered if I know for sure.

I'd also make note of the difference between the potential of a 2 valve for clean emissions vs what's actually empirically achieved in the past. The fact is 2 valve engines _are_ still around, and we're witnessing the demise of a ford multivalve (in the 6 - though it's not specifically replaced with a 2v option) engine or two.

[Billzilla]

I recall speaking to a bloke at Northern Mini, Henry Draper (whose link to the suzi motor might be known to some) who raced a swift or two somewhere sometime. he mentioned his affection for that engine, at the time, but also noted that there wasn't a hell of a lot that could be done to dramatically increase performance without valve interfernce and other issues.

FWIW we are making at least 50% more power than the stock engine, with stock compression and revs.
It's quite possible to get a lot more power from them.

Back in the mid 90's we built an unrestricted Suzuki, and it ran to 10,000rpm. I found that I could out-run Formula Two cars in it. :D
Then the parity rules came in and we lost 2,000rpm and compression and a lot of power ..... slowly getting back bit by bit though.

The fact is 2 valve engines _are_ still around, and we're witnessing the demise of a ford multivalve (in the 6 - though it's not specifically replaced with a 2v option) engine or two.

Just out of curiosity, how many two-valve engines are Euro 4 or 5 compliant? I know there's a handful that make Euro 4 ...

[Ze]

I thought they're a 60deg V8 the same as is the small block chev family. I'm talking the angle between the banks not crankshaft orientation. You're referring to the difference between a cross plane (90deg) crank and a flat plane (180deg) crank.

I think you're getting firing orders mixed up with physical layout.

What drugs are you smoking? Can I have some of that crack?

The SB and BB chev are 90 deg V engines and always have been through all their various incarnations. Windsor and Cleveland V8 as well as the ford big blocks and Y-blocks are 90 deg V8's as well. Then we've got the chrysler small blocks and big blocks , yet again all 90 deg V8's. Do i need to continue on and mention the pontiac V8 or the buick V8's?

Perhaps if you pulled your head out of your arse instead of pulling facts out of your colon with your tongue you might have a clue.

The only 60 deg V8 that I can think of is the ford/yamaha V8 based upon the duratec V6. http://en.wikipedia.org/wiki/Ford_Yamaha_V8_engine