I wanted to meet and greet a local mopar engine builder. Guy is 100% mopar. Has a great shop, and has a wealth of knowledge on Mopars, right down to the LA block, knows dates, years, what had what. Guy definitely passes the muster test and has some serious knowledge.
Anyhow, I mentioned I want to swim in the 13s on street tires and to look at as stock as possible. He built me out a spec for how to achieve my goals and to keep the car looking stock and/or period correct. Then later after I got home, he mentioned a second option which is starting to make a hell of a lot of sense, and it's more respectful to the car and the value of the car. I think Option 2 is now becoming the clear choice.
Keep in mind that the reason I'm discussing this is because the engine needs to be pulled to replace rear main and freeze plugs. That has prompted some planning that may occur over this winter or next.
Option 1: Pull engine and proceed with build.
- Stroker 416-418 kit w/ forged pistons and cast crank. He prefers cast due to 10lbs less on the rotating assembly. He's not a fan of Forged unless forged is required. Factory cast stroker cranks are still good for some serious HP that I won't even be making.
- CH318B heads with some bowl porting. They look very close to factory and support all the factory items. They flow very well out of the box, and with some minor work they flow really big. He prefers iron for my build and thinks that aluminum is overkill. He prefers Iron for down-load HP. Weight savings isn't enough to change his mind for this build
- 1.6 ratio rockers for extra lift
- 230 cam (@.050) with 110 lobe seperation. Likely a custom grind that he will do.
- Retain the LD340
- Retain the AVS 750 CFM, although recommends swapping to Thunder AVS 800
- Retain manifolds. He despises this, but understands the purpose. He wants me to know that those manifolds will be holding back the engine from making an easy 440 HP or above
This build should produce 390 HP, which should easily push the car into the 13s.
Option 2: Leave my damn engine alone. He commented that I have it tuned up very well. He said he runs very nice, and he liked the compression numbers I showed him. He said what some of you are saying: Build a 360 on the side, buy reproduction 340 stuff (Valve covers, oil pan) and build a 360 Stroker that looks exactly like a 340, and follow a similar build to what he prescribed above. With my factory 340 out, I can replace the freeze plugs, repaint it, clean it up, and keep it 100% drop-in ready and move it off to the side and bag-it.
Yup: I don't understand why a person would stroke a 340.
And to be more specific not just any 360, you want a roller block... I think the range is 90-95, something like that.... They are pretty common, I've seen three in the last few months on the local C/L with prices ranging from $100-$250... The $250 included a Ram Maxi Van....
I mostly agree , I still prefer forged pistons , the factory cast piston was special with a steel liner inside , much stronger than aftermarket cast pistons .
I would be more inclined to use a 112* LSA cam especially with the 1.6 rockers flatter torque curve with better street manners .
Roller LA blocks were 87-92 , 93 was the first year of the magnum
Quote from: Chryco Psycho on August 03, 2019, 08:27:15 PM
Roller LA blocks were 87-92 , 93 was the first year of the magnum
I'll trust ya on that, I know one when I see it, quit trying to memorize the years... I know the old stuff, the newer stuff not so much..
All Good , we just cover each other on the knowledge , 1 person cannot remember it all :bigthumb:
My engine builder friend has also told me he prefers cast pistons on builds where the engine is around 400 hp or less. He was saying that once upon a time, forged pistons were stronger and lighter and the way to go but over time, metallurgy improved so that cast pistons improved in strength and can actually be a bit lighter than a forged piece. He still uses forged pistons a lot but only if a customer insists on it or if the build is for a higher horsepower engine and demands the extra strength of forged.
A hydraulic stroker 360 will bring a '70 Auto Challenger into 13s gauaranteed and at low cost. No need to go to roller or add more aluminum was my take from the conversations. "If you want to, sure....but it's your money."
He was pretty specific about a cast crank. "It's your money..if you want forged then whatever...you'll never make enough power to benefit from forged and you have 10 more lbs of rotating weight to deal with."
He's very much into the forged piston option of the scat set, just doesn't think forged CRANK is worth it for a 400-450HP with extra rotating weight
I'm probably in good hands.
The cam isn't necessarily picked out quite yet. He wanted more info that what I could give him. I told him hot, but not hot enough to where your mother couldn't drive it. He's thinking about a 110 lobe separation. I have no power brakes. He would probably think a 112 would work too. "for camshaft, going slightly smaller is always better than going bigger."
He told me to reuse stock converter. Once you stroke and add the power that I'm adding, your stall will increase on its own.
After riding in my car he was pretty sure to leave my 340 alone....
You guys would prob like him. Maybe I can get him to join the forum....
Supposedly a lot of folks making 550+Hp with the cast SCAT stroker cranks. I think the Eagle version doesn't have the same reputation.
I picked up a clean '77 360 short block a couple weeks ago for $150 for my future build. Scat cast kit is on top of the list. My 340 isn't numbers matching or correct year, but I'm sure I'll be able to pay for a good chunk of the stroker build by selling it to someone who wants to get their car date code correct. I have a standing offer from a local guy to swap my 71 340 motor for his 73 and he'll add cash, whenever I'm ready to proceed. Before I do that though, I need to get the VIN out there and see if anybody still has the car.