305ci V8 vs. 292ci I6...just curious.

Hey Jon-

My Dad had a 292 in his 1977 3/4 ton. The engine was no screamer but had a ton torque on tap. We would regularily overload the truck with coal or wood- and it pulled like crazy. But the flip side it was a very thirsty for fuel engine.

His next truck a 90, has a 305- maybe not a smooth- but similiar power in my opinion.

M

J> Hi...

292 all the way! Great bottom-end torque, very reliable, smooth runner, odd sound with louder exhaust, EASY to work on, good selection of performance mods, great room to work on except in the front for obvious reasons, will almost always make a good bit more TQ than HP with streetable mods...

I have known 300HP/400ft/lb VERY streetable 292's doing allot of heavy working.

I have no faith or trust in the power or reliability of 305's from allot of experience with them. Even the early Camaro/Firebird TPI 305's were nothing impressive.

You should have seen 292's in their prime from 1965 thru 1970 or so. They were real stump pullers and had good power to. Heck a 250 of the same time frame had more power than the later smogged 292. I had a 66

3/4 ton chevy in early 70's with a 250, a 4 speed and 4.57 gears. That thing would pull anything you hooked up to it. Trucks were trucks back then.

----------------- TheSnoMan.com

I will agree the 292 is a pull the house down engine, gobs and gobs of torque, but then inline engines always produce good torque, always have. Down side is just like the ford 300 if it sees a fuel tanker it wants to nurse, due in part to its long stroke design. The only major difference between the 292 and the 230 is the stroke..

I think the 305 gets a lot of bad press. it is what it was, an entry level small v-8 engine. It wasn't going to pull like the 350, but it also would go further on a tank of gas. I think that's the real reason for the hammering it gets, it aint no 350. I got a thing for 283 engines, in a small light vehicle like a box nova or a Vega, its a terror, do a little work on it in the same body and its a rat slayer, put the same thing in a Impala, Chevelle, caprice, and it aint so hot. The advantage of a V design engine is more displacement in a smaller engine bay.. But there is more power waste in the v design, because the banks do fight themselves somewhat for lack of a better way to say it there is more rotational resistance. European ford tauras models and tanus (that one that never made it over here) used v-4 engines for a smaller engine bay with more displacement, and more passenger room in the same wheel base and over all dimensions. The Opel Rekord was about the same size as the Taurus, base engine a smaller inline 4 , but it would walk the dog on the ford, for that mater the ford escort with the 1100cc inline engine would beat up on the tanus with its 1800cc V-4. Both cars were slightly smaller than a box nova, about the size the 61-62 American Ford Falcon(the Rekord and Taurus).

Whitelightning

AMEN!!!

The stroke is not the cause of the poorer MPG it is the overall engine tune and low compression ratio that reduces thermodynamic efficency and increase gas usage. 6's of the 60's were pretty thrifty before emission controls hit them and the 250 and 292 got hit hard by them. (the old chysler 225 slant 6's were a bit of a stump puller too back then and smooth as silk and good on gas and they had a really long stroke too) The 230 and 250 share blocks but the 292 has a tall block and it is easy to spot because on the larger/taller valve lifter covers on side of engine as well as taller block. When I worked in construction back is 70's driving a dump truck frequently, I met the old retired man that used to do some contract hauling for 40/hr when we needed extra trucks on a job. He had a 1958 Chevy C60 single axle dump with a 261 and a 8 speed (4 x2) and it was cherry and not even rusted at all. He would haul 8 tons at a time and average around 8 to

10 MPG doing it (higher number on longer trips). It never seemed to lack power for what he did and was quiet to when he would roll up with its stock exhaust and engine was as smooth as could be too. They made some really great 6's back then and V8 only really took hold as base engines after emissions killed the 6's and bigger engines were needed for the same general level of power.

----------------- TheSnoMan.com

I had forgotten about the deck height, that's how they gained clearance for the longer stroke..

And I wouldn't consider 10 mpg good. Look at Fords 300, it will out pull torque wise a 5.0 V-8, but burns way more gas doing it.

Whitelightning

I had a early 70's F-250 300 in six with a 4 speed manual trans. It was a great truck, lots of power, easy on gas. I loved it. So in 87 I bought a new F-150 with a 300 in six, HD 4 speed manual. It was a DOG. Was almost impossible to get rolling without zinging the throttle, got 15 MPG on the highway. Had it back to Ford a number of times and they kept telling me "they're all like that." They told me that was the first port injected six and Ford had no fix for the problems.I screwedd around with it for a while trying to figure out the problem with no luck, so I sold it. The gal I sold it to came back a few days later, the fuel tank switching valve went nuts and fuel was running out of one of the tanks. Ford had a recall on it but of course it did not cover the 87's. Did I mention the paint started falling off at about 1 year? Ford decided to re-paint it about six months after I sold it.

Al

8-10 MPG hauling a GVW of around 28K it really good MPG. the Ford 300 was a good engine too back then but I would have to side with the 292 because it had better top end power and did not run out of breath as quickly as the 300 did. V8's like the 289, 302 and 283 and such did not have the needed torque at lower RPM's but the had a 327 truck motor that did pretty good. Back in the 60's they used to put a data plate in the cab on inside kick panel (left side under dash) that used to stated net HP of engine option not gross HP

----------------- TheSnoMan.com

400ft/lbs?!?!?! I need to know about this engine!

~jp

Shades (at dot) wrote:

Not real hard to build IF you can still find all the pieces. Clifford research has some really GOOD parts for the straight sixes that made some reliable power out of them. I built a 250 into a beast for in my old Nova and it embarrassed quite a few folks to be left behind by a puny 6 cylinder... The weak spot in it was the crankshaft. That got replaced with a billet steel part that could stand the pressure. When it finally got dyno'd I had almost 250 HP at the rear wheels. That was through a Powerglide and a 9" with 4:10 gears. You couldn't mistake it IF the hood was open. The factory didn't fit the 6 with 3, 2 barrel carbs or a split tri-y header with 4" collectors. Had a very distinct exhaust note.

Any idea where peak torque was in that motor? I'm curious how much low-end it could make, and how difficult it'd be to make peak torque around 1800-2000rpm with such an engine.

~jp

Steve W. wrote:

What's the compression ratio of the 292, and would that low number make it an ideal candidate for forced induction?

~jp

SnoMan wrote:

Well, I gotta say I'm liking the idea of this engine more and more. Since the Blazer has been redesignated as a "project" vehicle, I have room for experimentation and plenty of time to review all the options before making a decision.

I don't want or need a screaming smallblock that revs high. I just want something that runs well on the street and has the power to pull a small camper or the occasional U-Haul trailer, and doesn't kill me on gas. The 292 sounds like it could be that engine.

I'm much more concerned with torque than HP; specifically the highest torque possible at a lower RPM (preferably around the 2000rpm mark). Forced induction is very do-able, and I'd plan on rebuilding from the ground up anyway, so I could easily plan for a lower compression ratio.

Plus I think I could finance much of this by selling off my 350...which technically is "fine", just not for a truck. Not to mention that the

305 actually ran better, and that from what everyone is saying, the 292 is better than the 305.

I used to get around 17mpg on the interstate in the K5. I'd love to see that again.

~jp

Steve W. wrote:

Cool article on rebuilding an I6 in case anyone's interested:

~jp

THe presmog ones were about 8.5 to one and the late smog motors were aaround 7.5 to one. Yes forced induction should work well with them.

----------------- TheSnoMan.com

Consider this, the pre smog controlled 292's peaked their torque at about 1600 RPM so a stock 292 with a blower would be a real stump puller.

----------------- TheSnoMan.com

Well then... In that case, considering that I have the smallest of full-sized Chevy trucks, I think that may be the route I take.

I'd kinda been cooking up schemes about what I'd do if it were a project truck, and those things included weight reduction, by means of fiberglass hood and front fenders, and 86-ing the hard top in favor of a half-cab conversion or soft top. The "6" would probably do nicely in there, and I'm guessing it weighs less than a 350 :-)

I am having a difficult time finding multiple performance parts for a

292. I'm sure it comes down to the way I'm searching. It's easy to type "small block chevy" into Google and get endless results.

~jp

SnoMan wrote: