340 4bbl

Hi everyone from New Zealand. (We're also known as kiwis). Thanks for the join.I'm interested in learning everything about the 67 340 4bbl motor. I have found a one owner motor and 2sp auto with only 53000mls on it.I would love to know 3 main things to start with. (1) is the factory hp and tq figures correct??has anone dynoed a original car.(2)because this motor will used as a transplant,can anyone tell me what the weight of the motor and box is?? (3) I know there is stuff all aftermarket parts available for these motors but,with basic porting and port matching and a cam change etc(anything that doenst require a rebuild) what hp/tq figures have you achieved?? anyone ever put there 340 down the 1/4

 

That engine evolved from an all aluminum 215 V8 that was manufactured from 61 to 63 and later licensed to Rover who built the engine until BMW bought them out about 10 years ago. In 64 the displacement was increased to 300 and the block became cast iron, still with aluminum heads. In 65 the heads were cast iron. The stroke was increased and it became the 340 which was only produced in 66 and 67. Both the 300 and 340 were available in 66 and 67 but the 300 was only available as a 2 barrel those 2 years. The cast iron 300 heads and the 340 heads are identical as are the pistons, timing cover, bell housing, flywheel. There is a V6 version of this engine that started out as a 196 in 62 and 225 in 64 to 67 that was widely used in Jeeps and then returned as a 231 in 74, this was the base engine used in the Turbo Gran National. In 68 the 340 was bored .050" and became the a 350 with totally redesigned heads. Not many parts interchange between the 340 and 350 since the valve arrangement is different.

A 340 with a 4 barrel produces 260 hp (if it has 10.25:1 compression ratio) and 375 ft lb of torque. There are a variety of cams available since the 215/300/340 can all interchange cams. I would guess that it would weigh about 550 lbs. Derek (300sbb_overkill) knows many speed tricks for this engine.

 

Cheers for that,from what I manage to find out so far is the only thing that can be done head and manifold wise is basic clean up and port matching,with that being done what improvements can be expected??I would also be adding a set of extractors or block huggers(depends on room)

 

Phil gave you a good history lesson for the evolution of the sbb engine platform. Going back to the 215 that was sold to Rover back in 1963, TA Performance makes a performance aluminum head for the Rover engine that would bolt onto a 340! Ported those heads can flow some impressive numbers and would feed 340 cubes very well. The only problem is they don't make an aftermarket intake for the 340 so you would have to use the one you have.

Port matching is a waste of time that will put a bulge in the middle of the intake tact that would more than likely slow down air flow and make less power doing it. If you're lucky a port match job won't effect anything but usually its the opposite that would happen doing it.

If the heads get fully ported, then port matching the intake to the fully ported ports would be helpful to increase power output as well as doing the Doc's dual plane mod that is in the Nailhead section in a thread that is a sticky.(sticky= one of the threads at the top of that section)

Not sure how shipping from eBay is from the states to there but if in its not to horrible then there are also nascar take out rods that can be made to work in your little 340 if you're interested in making it a stroker? How far do you want to take your 340? What kind of power do you want it to make? And what kind of budget are you working with? Answer those questions and we'll be able to help you get where you want to go with your 340.

 

Here is a link to the dual plane mod thread;

http://www.v8buick.com/index.php?threads/docs-dual-plane-mod-and-port-matching-stky.225437/

 

Due to the fact I know nothing about what's possible with these motors can you or anyone else shed some light on what the factory motor produced on a dyno atrw?? Using this info would help set up a relistic goal. Being from the other side of the world parts prices that you pay,it would be double for me to purchase. I love buicks for the awesome tq they have and with any motifications to increase hp,what effect does it have on the tq curve? ? Would I be off the mark expecting to get 250rwhp from a 340??

 

Adding to my problem is i have been searching for over a year for any type of buick motor and this 340 is all that's available in nz. Will be a 90% street driven car with the odd play at the track. If I could do a 13 from a 3000lb car I would be happy

 

Very cool,any idea on what result you get??