Seff

I cannot get my Supreme insured unless I can verify the horsepower rating of the engine. Right now they want to set it at 375 HP and charge me accordingly, but I have read enough threads about tuning a 350 to know that there's no way my stock '72 350 came with that kind of power.

Does anyone have a credible and quotable source for a horsepower rating for the '72 350 4 barrel? They don't care about torque rating.

I've read and heard 180 net HP and 275 ft lb, but I've seen no documentation for it.

As an extra question, does anyone know what difference a set of high compression pistons will make for the power of the engine, assuming all other things are unchanged?

Thanks.

Lady72nRob71

Leave it to the insurance scammers to double the assumed HP just so they can charge you more...
180HP is correct; the sales literature states them. I have a hard copy at home but they can be found online, too.

1970cs

See if this helps!
http://wildaboutcarsonline.com/membe...ECS_Jan.72.pdf
Pat

Seff

That's exactly what I needed, thanks a bunch!

droldsmorland

If an insurance company asks that question about a stock(ish) 72 Olds it must not be a classic car insurer. Go to the JC Taylor, Hagerty, Grundy, etc... Others will pipe up with other companies. Your daily driver insurance company is NOT who you want to do insurance with for many reasons. One when it comes time for an accident repair, two policy cost and terms.
The tell-all is how they handle a claim. I’ve heard many horror stories. I’ve been with JC since the late 80s. Stated or agreed value(professional appraisal required above 30K) etc.... Never heard of a classic car insurance co ask that question. Now a Hot Rod/race car insurance policy yes because of high HP modifications.

Lady72nRob71

He lives in Denmark, so their gooberment and insurance companies operate differently than ours. They also have limited knowledge on old American cars...

11971four4two

Changing to flat top pistons and doing nothing else is not a good idea.
Something else to think on... high compression engines have detonation problems (ping) on low octane fuels. Not pump gas friendly

The horsepower rating is so low (180) due to the rating being changed from bhp (brake horsepower) to net horsepower in 1972. nethp ratings will be lower for the same engine than what the bhp is.

So 180 nethp 1972 motor is about the same as the below example of a 71 would be




The 1971 editions of the 350 cubic inch Rocket V8 engine have a brake horsepower rating of 240 at 4,200 rpm. The torque of these engines is 350 foot-pounds at 2,400 rpm. A compression ratio of 8.5 to one is used for the Rocket V-8s as well as a bore of 4.057 inches and a stroke of 3.385 inches.

joe_padavano

Both are BHP ratings. The difference is that the 1972 number is net HP, which includes stock air cleaner, exhaust, and accessories. The earlier numbers are gross HP, which did not have these added restrictions. The net number is a lot closer to reality. The two test methods are well documented in SAE literature.

Seff

Ah, I've been imprecise in my description of the build - they're not flat-top pistons, they're NOS .40 pistons for a 1987 Olds 350, to be put in my '72. I believe what you said, though.

Here's a good question: When choosing a transmission, should I count on the net or gross torque rating? Just wondering, and thanks for the replies. :P

Seff

I noticed now, after I talked to both the registering and insurance guys, that the 180 HP rating is for single exhaust. I have dual exhausts with headers. What kind of difference will that make? Does torque rise as well?

Lady72nRob71

HP rises to around 200 I've heard if on a 4bbl.

Seff

Gotcha. Still within my 20% power increase limit, then.

Thank you.

oldsguybry

I've been with Allstate for over 20yrs , and I beleive I pay a little over $400 every 6 months for three cars . I know I don't have full coverage on two of them , and i'm not sure if I do anymore on the other one either ( can't find a bill for reference ) and I think I changed the deductable to $500 a while back too . The only thing they wanted to know was the engine size on my 72 . I do remember back in 92 when I wanted a 5.0 , they wanted like $650 every 6 months so I ended up settling on a 5 speed 92 Cavalier instead .... that car lasted forever .

Seff

I live in Denmark, and the best offer I've gotten so far, for just covering the damage I cause on other people's property, is $3000 a year. For 8000 driven miles with a driver that's 21, and male. Go figure.

oldsguybry

Yea , I didn't realize you were in Denmark , and wow that's a lot of money .

Seff

Gotta put it into perspective, though. The car has cost me $21000 to build so far, including a paint job worth $8400, an engine boring and three angle valve job worth $2500. Getting it registered will cost me another $3300.

Wages for a soldier boy like me before tax is $3100 a month, of which I pay taxes until I have $2000 a month. Except in A-stan, where I've been getting $5000 a month, after taxes.

Gas costs roughly $8 a gallon over here. Minimum wages are $20 an hour. So you can't REALLY compare it like that.