I would love to keep my buick all buick but I am looking for the power and reliability the zz4 has. Its going in a67 4 door special thes loaded. I was wondering if i could build the 340 and make the same power it does (350hp/405lb) What would it take? Cam Head work etc, etc. ThankDoug
Considering that the 260 hp the 340-4 made in 1967 is only 195 hp in modern mesurements, you have a long way to go to get to 350hp. Given that you already have high compression and efficient exhaust manifolds, there are less areas to work on. Others have commented where the 340 can be improved. Search this forum for "340" to find those posts.
Harry is the 260 number what it made at the flywheel or is the 195 number the flywheel. The 350 number on the zz4 is flywheel. I know a 350 buick could make those numbers but would it fit in the car with a set of headers?? doug
Before the 1972 model year, horsepower of new cars sold in the USA was measured without typical belt-driven accessories attached. 1972 regulations resulted in about a 22 percent drop in rated horsepower, based on some research I did years ago comparing specs from 1971 and 1972. A 350 would fit, as would a 455. Many people have one or the other in '67's, often with headers. Headers on a 340 are the worst fit.
The 340 is reliable It probably wont make the power the ZZ4 will, but the cool factor will go WAAAAY down when yah pop the hood and people see a SBC in there.
I'm not sure why you think the 340 wouldn't be reliable. it doesn't have any known issues that make it less reliable than a sbc.
I will defend the 340. I have 1 in my gs340. Crower solid cam 650 holley double pumper Recurved hei distributor Sanderson headers with 2.5 outlets and full 2.5 exhaust. Connected to a m20 muncie and a 3.31 12 bolt posi its a blast to drive. Not sure why everyone thinks that the 340 ext manifolds are efficient but they are JUNK!!! With 1.75 outlets they choke the 340 to death. The headers with 2.5 outlet more than double the calculated area of outlet compared to stock and let it breathe . And seat of the pants made a bigger difference than any other mod to my 340! Would not work with factory z bar tho. I had to convert to a hydro slave and master. Sorry for the rant on manifolds lol i just feel like theres a big misconception about them!
If you have any concern about originality at all, then yes, the 340 is a capable engine. Look, if you had a little money to spend then a set of TA Rover heads, roller cam, headers, and all you need then is decent compression and a good intake. To be fair, the intake and heads are the limiting factor, mostly the intake. The only differences between the 340 and 350 (Buick) is in the heads and intake. So is a good intake available for the 340? Well, no not really. The stock iron intake is OK but in the aftermarket the 340 is an orphan. You can use spacers to fit a 300 intake, or even a Rover intake, and some of those are pretty good. But for the Rover versions your port spacers would be 1-3/16" thick and you'd need to make a valley cover. Kinda cuts into hood clearance in some cases. Since I was using a blower anyway that wasn't a limiting factor, so there is the solution for the 340. Forced induction. Do that and it'll match the Buick 350 in every way. The deck also gives you room to use longer rods. I was able to buy some very light Scat rods made for the FHF that were 7" long and use them with light forged Venolia pistons to get a zero deck and 10.6 CR and for my application this works out really nice since I only need enough boost to help on the top end. The engine has a lovely wicked sound, several of my buddies have told me it's the best sounding engine they've heard. Lots of power. Don't know what it'd do on the dyno and no immediate plans to find out, but it's well above the stock output and still idles nice. Jim
Jim I would like to see the blower setup! That has to be pretty awesome Any pics? I agree about the intake also. I did the doc nailhead manifold mod To my stock 340 4 brl intake. Seemed to be a step in the right direction then with a 2 inch 4 hole spacer it really stepped up the bottom and mid range grunt. I never shift it past 5k anyway. Im a little scared of those scrawny rod bolts they came with
