#'s Matching 340 build
Hey Garrett, you do realize that pistons for this are a custom order since MP no longer carries parts for there discontinued line. 3.65 - 3.58 = a lot of stroke difference for a stock or even a replacement/performance piston. I guess you could have something made up if a regular slug did t fit. (Honestly, I would love to try just for fun. I love to tinker) While I think it is an excellent route to go, one I’m sure RAMM is up to performing, it would be the rest of the external parts package I would question and call questionable in it’s effectiveness with a 40 cubic inch increase. Below is a quote from the opening post;
This leaves just one question which I’m not 100% on, is the owner of this engine/car build making use of headers? Because at that point, I’d look into porting the heads really well. If I had to use the exhaust manifolds, that would change a thing or two.
Sr71mopar made a comment, “Kind I’d like a FAST build.”
If I decided to do a FAST engine, it would be for competition and nothing else, (believe me, I think about doing this for fun but on a lower non competition level) but because of the power limitations of a stock head and exhaust manifolds. This becomes less appealing. At least for something I’d like to drive and enjoy rather than street/track race.
While I think that 3.65" stroke crank is very appealing it's just not going to happen. The customer is not really interested in all out power nor is he interested in a $10k+ bill as we discussed. A FAST type build is not in the cards and I wouldn't recommend a large cubic inch stroker with X castings for a '69 Dart on a good day.
When exhaust limited as in this case--smaller cubes are your friend. A larger cube engine moves more air and fuel which means the already restrictive exhaust becomes MORE restrictive which drives the power curve DOWN. A 416 or actually a 418 in this case with X heads and stock exhaust manifolds without MAX effort everything will peak at a mind blowing (<sarcasm) 5000rpm--maybe lower.
I will try my best to work within the customers criteria. The criteria is always time, budget, reliabilty, output. In this case I have a surplus of leeway in time and output. What this means is the customer has given me an abundance of time and isn't all that concerned with output. It is paramount that the engine is reliable/driveable and within the budget. (on no greater than 91 octane)
Where I'm caught is I can't NOT try to make as much power as possible within the above parameters.
Most of the allure of a 340 powered '69 4 spd Dart is the high RPM a 340 willingly achieved. A 5000 MAX rpm 400+ cube 340 does not measure up here in IMHO.
So having said all that the engine will be tested with headers on the dyno so we will never really know the results with manifolds as installed in the car. However, the engine will be built to produce well over 300HP @ 5800 rpm or higher and meet all other criteria. It's a pretty tall order when you consider:
Can't throw compression at it
Can't throw an aftermarket intake on it
Can't throw a big cam at it
Can't throw good heads on it
Can't throw headers on it (in the car)
Can't throw a Holley on it (always better than a Carter)
Can't throw a stroker crank in it
What I CAN do is:
Perform the most accurate and relevant machine work within my abilities
Utilize modern internal engine components when feasible
Nail the valve timing events
Execute the right cylinder head work
I could and am already leaning on FABO for more ideas. Thanks, J.Rob
