Buick V6 or 304 V8?

Understand and agree with what you are saying Tim. The 304 dropped almost 30% in 72. If the V6 were to drop that same percentage it would leave that motor at only 105HP. I can agree that it is possible that is all the power that motor made.

So I have to concede that one.

I have also never owned a jeep with a V6. Would sure like to one day. It was always my impression that the V6 was a great motor for the smaller 71 down jeeps.

 

Sparky, insult? I'm certainly not offended.

Permit me to elaborate.

I've heard this rather general assertion repeated in several forms here: that the intermediate Jeeps are a lot heavier than the early CJs, or that the AMC engines are weak compared to the Buicks, or that the performance of the V6 is somehow extraordinary compared to engines of the era with similar displacement. I don't think that any of them are true, and I felt I should speak up. Also, I countered your statement because I was interested, and wanted to test my understanding against the response of you and others on the board.

My feeling is that, all other factors being equal, factory-tuned engines from a specific era and aimed at the same market will have power outputs in proportion to their displacements. There's a lot of truth to the popular saying "there's no replacement for displacement." All the major manufacturers had access to the same technology, shared the same market, and built their engines according to both.

With regard to the weight difference, I think a similarly equipped CJ from '71 and '72 will be within, say 250# of each other. The V6 (414#) is lighter than either the inline 6 (500#) or the 304 (540#) but all three are lighter than a SBC (575#) and certainly lighter than the F134 (600#? a guess). So, guessing high, a 258 CJ has maybe an extra 150# of metal in the body and frame, and 86# more engine. Everything else is accessories, which both the '71 and '72 would be equally penalized by. I can't see a reason for a big weight difference.

 

Just to set things straight...No matter what anyone says about the 225 vs. 304 I will not be offended. I have driven the 304, 225 and a 231 and my 2 cents is keep the :v6: it is a good motor. It is very tourqy and does fairly good on gas. Also the 231 was oddfire for a while then went to evenfire. Can't remeber if someone said the 231 was evenfire in this thread. :? Oh well. keep both jeeps if you can but if you can't sell the 74' to someone who wants it and keep the 71' Just my thoughts

1971 CJ5 :v6: w/HEI
1994 Tucker Sno-Cat T1000
2005 GMC 2500HD duramax diesel

"Things are looking up." Brekshire Brewing Company

 

One thing to think about is those HP numbers are from the factory paperwork. I would dare say they are not exact, manufacturers fudge the numbers one way or another to get the disired effect; more HP then reality more people wanting Insurance hating it, less HP then reality fewer people wanting it but insurance not knowing any better.

 

Patrick what I ment was these were factory published numbers which I rarely believe.

Heads up, motor to motor. Or should the V-8 get one stage of NOS :twisted: J/K

 

I thought it was still crankshaft horsepower only with all the engine accessories added in. Also with factory manifolds, carburetion ect...

 

HP was never measured at rear wheels. SAE gross in the 60's was the motor. SAE net circa '72 was the motor as intsalled in the vehicle: alternator, air cleaner, exhaust, etc. From 70-71 most "high performance" engines lost a full point of compression ratio if not more. Trucks and jeeps not so much since they didn't have 10 or 11:1 compression to begin with.

IMO, the V6 is superior in an ECJ5 because of packaging. For most applications offroad, power output is not near as important as gearing. (mud racing and sand drags the exception!) If you need more power it's most likely for highway duty.

 

if you want more power keep the v6 and do some moderate building to it and youll be impressed with the power it has

 

I love my chevy 350 swap. But in your situation, I'd keep the V6. Leave the 304 where it is and spend the time/money you would have in the swap and invest it in the V6.