GM Sticks with Pushrods

ozrunner · 25-10-2012, 03:40 AM

Although it looks impressive you have to ask if GM will ever move into the modern era and make the jump from big cube pushrod engines and move to modern DOHC technology.

http://blogs.hotrod.com/chevrolet-de...ine-38589.html

FGX-351 · 25-10-2012, 04:42 AM

The Gen 5 LT1 finally emerges.

This engine seems like it has quite abit of potential.
Will be very interesting to see how it goes in the Commodore body.
Based on that article, I still believe the Miami to be the greater engine.

burnz · 25-10-2012, 04:55 AM

Quote:

Originally Posted by ozrunner

Although it looks impressive you have to ask if GM will ever move into the modern era and make the jump from big cube pushrod engines and move to old DOHC technology.

http://blogs.hotrod.com/chevrolet-de...ine-38589.html

ignorance is bliss.

smoo · 25-10-2012, 04:57 AM

What do you mean modern dohc, Mercedes and Jaguar were selling them in the 1950s.
Considering most petrol engines can't even break 40% efficiency the whole pushrod v ohc arguement is like saying an EA Falcon has better build quality than a VN

99AUXR · 25-10-2012, 05:01 AM

Nothing wrong with push rods....

MethodX · 25-10-2012, 05:28 AM

GM has already made OHC V8's for Cadillac.
Anyway hope this one goes well and Holden get a good version.
This new motor has Direct injection and VVT. not bad.

pottery beige · 25-10-2012, 06:20 AM

Quote:

Originally Posted by 99AUXR

Nothing wrong with push rods....

this...

Nikked · 25-10-2012, 07:19 AM

The Gen 3 is one of the most popular V8 ever...compact, lightweight and can make big power...

GM have already played with DOHC...Northstar, C4 ZR1...

**Luke Plaizier** · 25-10-2012, 07:55 AM

I wonder when Coyote/Miami will get Direct Injection, and what sort of power/economy improvements are yet to come?

Lukeyson

turbodewd · 25-10-2012, 08:17 AM

Judge ye engine not by its parts but by its input-to-output. IF a pushrod V8 can pull off respectable economy and power...then go for it.

jpd80 · 25-10-2012, 08:23 AM

450 hp and 450 lb ft is a very formidable and cost effective unit for HSV,

will this be their top engine for GTS or basic for Clubsport?

Lardman · 25-10-2012, 08:37 AM

Quote:

Originally Posted by 99AUXR

Nothing wrong with push rods....

Eyup - with EFI and VVT there's not that much you're missing out on.

atec77 · 25-10-2012, 08:42 AM

Quote:

Originally Posted by ozrunner

Although it looks impressive you have to ask if GM will ever move into the modern era and make the jump from big cube pushrod engines and move to modern DOHC technology.

http://blogs.hotrod.com/chevrolet-de...ine-38589.html

No rush to drop pushrods although I would expect the next iteration to be ohc if the engine bay allows a slightly larger motor , ohc has been around since the 1920's in Euro cars and Pontiac has several ohc motors in the lineup . Not going to ohc yet suggests the engine with those outputs has to be good for sometime , I wont be rushing out for one though as the ohc regime has good reasons for its use .

FGII-XR6 · 25-10-2012, 09:03 AM

holden seems to be stuck in a cycle of drill it out and put bigger slugs in rather than moving with the times . lets face it, this is just a tarted up tractor engine.
to the best of my knowledge there ahasn't been a push rod engine in FOAs line up for 10 years , the last one being the 5.0 windsor

lets look at figures
GM 6.2L pushrod V8 335 KW
Ford 5.0L quad cam V8 335KW
Ford 4.0 twin cam I6 310 KW

using technology you can have a 4.0 6 that is only 25Kw short of a 6.2L tractor engine

Brazen · 25-10-2012, 09:04 AM

Pushrods for me thanks, they are beautifully simple and smart - you use the space between cylinder banks for the pushrods and camshaft whereas a OHC engine needs to be much wider and taller. You can position a pushrods engine lower down and further back in the engine bay - negating the classic front end heaviness you more often encounter in a OHC V8 car. To put it in perspective a GM 6 litre V8 is 20 cm narrower than a 4.5 litre Porsche V8 and lighter. The GM V8 family is also easy to assemble making long term maintenance a lot cheaper.

If you look at physical size, cost and weight to performance and efficency pushrods can't be beat.

99AUXR · 25-10-2012, 09:05 AM

Quote:

Originally Posted by atec77

I wont be rushing out for one though as the ohc regime has good reasons for its use .

Simply OHC/DOHC will not give you any real advantage except the pushrod engine with similar power output would normally have more cubes.

Quote:

Originally Posted by au3xr6

lets look at figures
GM 6.2L pushrod V8 335 KW
Ford 5.0L quad cam V8 335KW
Ford 4.0 twin cam I6 310 KW

using technology you can have a 4.0 6 that is only 25Kw short of a 6.2L tractor engine

You cant really compare a turboed car to a N/A in the terms you are talking. Why dont you compare the push rod to the Barra 4.0 DOHC without the turbo.

4L DOHC I6 195 kW
GM 6.2L pushrod V8 335 KW

Those extra two cylinders seem to be earning their keep lol.

Brazen · 25-10-2012, 09:10 AM

Quote:

Originally Posted by au3xr6

holden seems to be stuck in a cycle of drill it out and put bigger slugs in rather than moving with the times . lets face it, this is just a tarted up tractor engine.
to the best of my knowledge there ahasn't been a push rod engine in FOAs line up for 10 years , the last one being the 5.0 windsor

lets look at figures
GM 6.2L pushrod V8 335 KW
Ford 5.0L quad cam V8 335KW
Ford 4.0 twin cam I6 310 KW

using technology you can have a 4.0 6 that is only 25Kw short of a 6.2L tractor engine

Displacement is a number and is neither a positive or a negative, all your stats shows is that GM has matched the performance of the Fords using a simple, inexpensive, lightweight and physically compact engine.

dimka100 · 25-10-2012, 09:33 AM

Don't forget this engine will be Euro 6 and latest Californian emissions requirements compliant out of the door!

mik · 25-10-2012, 09:42 AM

the 2 best things about these engines, compactness and cheapness,
the plus side for rodders once these DI versions become more popular the older version will be even cheaper.

zilo · 25-10-2012, 09:48 AM

Bring back the carburettor,points and the valve radios.

smoo · 25-10-2012, 09:48 AM

Quote:

Originally Posted by au3xr6

holden seems to be stuck in a cycle of drill it out and put bigger slugs in rather than moving with the times . lets face it, this is just a tarted up tractor engine.
to the best of my knowledge there ahasn't been a push rod engine in FOAs line up for 10 years , the last one being the 5.0 windsor

lets look at figures
GM 6.2L pushrod V8 335 KW
Ford 5.0L quad cam V8 335KW
Ford 4.0 twin cam I6 310 KW

using technology you can have a 4.0 6 that is only 25Kw short of a 6.2L tractor engine

Ford were one of the last to drop pushrods, well behind the euros and japs. I'm just trying to think how more technology made the 5.4 Ford the better engine 10 years ago... Heavy cast iron block, more valves to burn which it loved doing, expensive timing chain rattles with weak tensioners, and an engine that was so physically big it struggled to fit in one of the largest cars on the market. To top it off it couldn't even match the LS1 for performance. As for tractor engines you'll probably find the 4.0 (as much as i love it) is closer to one than this new small block Chev. Looks like the legend will live to 60.

BHDOGS · 25-10-2012, 10:08 AM

If only we could get this much love for ford products on this forum

99AUXR · 25-10-2012, 10:11 AM

Quote:

Originally Posted by BHDOGS

If only we could get this much love for ford products on this forum

We do, however it looked like this thread was created to bash push rod engines when they aren't a bad thing...

Another thing you will notice is the people defending the push rod etc. are actually the ones that show some interest in our own product aswell.

FGII-XR6 · 25-10-2012, 10:30 AM

Quote:

Originally Posted by Brazen

Displacement is a number and is neither a positive or a negative, all your stats shows is that GM has matched the performance of the Fords using a simple, inexpensive, lightweight and physically compact engine.

that needs to tow a fuel tanker around to feed it's outdated large capacity low tech mechanical configuration. push rods are antiquated tired technology as I said before holdens answer is drill it out and put in bigger slugs ,don't wory about fuel consumption

jpd80 · 25-10-2012, 10:31 AM

Quote:

Originally Posted by Lardman

Eyup - with EFI and VVT there's not that much you're missing out on.

The one thing that's always been a standout with pushrod design is the compact siz of engines
and the relative ease of manufacture and provision of big capacity.

No doubt the FPV S/C 5.0 is a work of art but I sometimes wonder whether a S/C DI VVT 5.0 V8 Chev could be just as impressive....

FGII-XR6 · 25-10-2012, 10:34 AM

Quote:

Originally Posted by smoo

Ford were one of the last to drop pushrods, well behind the euros and japs.

looks to me like you are missing the point ford DID drop pushrods 10 years ago while holden are still using outdated designs. good the see the holden brigade on here can still talk up antique designs because it is a holden

pottery beige · 25-10-2012, 10:42 AM

some just don't get it.. engine is just an air pump.. doesnt matter how it does it as long as it does it well....

FGII-XR6 · 25-10-2012, 10:51 AM

Quote:

Originally Posted by pottery beige

some just don't get it.. engine is just an air pump.. doesnt matter how it does it as long as it does it well....

you are partly right but the greater the efficency of air exchange the better off you are. with OHC you get multi valve technology which improves efficency. it's like putting in bigger valves but better . you also have greater losses in transfering the action of the camshaft through push rods more friction therfore more heat. failure of push rods at high engine speed is another issue as is increased risk of valve bounce.
the list goes on but you get the idea, push rods belong in tractors not performance cars

99AUXR · 25-10-2012, 10:52 AM

Quote:

Originally Posted by burnz

ignorance is bliss.

Yip...

Push rods are easily replaced.

Sprint · 25-10-2012, 10:57 AM

Quote:

Originally Posted by 99AUXR

We do, however it looked like this thread was created to bash push rod engines when they aren't a bad thing...

Another thing you will notice is the people defending the push rod etc. are actually the ones that show some interest in our own product aswell.

I dont think anyone is bashing good ole pushrods but you are living in the past if you think there is no advantage to OHC or DOHC.

Direct cam action onto the valves with no pushrod tollerances to get into the way.

time to move on from the 70 year old chev design i think, stop living in the aussie 80,s lol