Stroker Combo's for a 400 and 4.15 Crank....?

[MOPARMAGA]

Yah, it would seem the 4.25 stroke crank would be a more viable option.....I was just trying to determine if getting the 4.15 stroke crank would be worth it. Like I mentioned, I have a Molnar 3.91 crank and 6.535 rods so I'll concentrate on that. What brand bearings are most guys going with these days? I have a set of Durabond PDP17 cam bearings (JustMoparJoe) for when I get the block work done - but what about main & rod bearings?? Thank you all.....

I personally would build the 470 & stick with it, you can make as much power as you want. My engine has put out really good power for a very simple combo. I used and still do use the clevite from 440 source since they're champhered.

 

[mopowers]

I'm pondering the same question for a big block build for my '66 Dart and am leaning 470. It seems to be a nice package that can still have a decent rpm band without having to jump to a max wedge port window.

 

[AndyF]

I've searched but can't seem to find what I'm looking for. I downloaded a chart (from Andy F, I think) for a 470 build using a 400 block and 3.91 crank showing the different length rods (Big Block Chevy) and piston combo's but I don't know how to come up with those stats for a 400 block with a 4.15 stroke crank. I looked at 440 Source but they only list one - 500 cubes with a 6.760 rod and it uses a piston that requires oil ring supports and I don't want to do that. Was thinking a shorter rod - 6.535 or 6.385 may work but no idea about the piston possibilities....Any help or resource would be appreciated. Thank you....

Which 4.150 crank is it? If it is a good crank and you can get it cheap then it might be a decent deal. If it was me I'd only buy a 4.150 crank if it had the 2.200 journals. I'd also prefer a 6 bolt crank and a high quality mfg.
If the crank you are looking at doesn't meet those specs then either build a 470 or a 512. Either will work with your TF240 heads.

 

[DGrace]

Which 4.150 crank is it? If it is a good crank and you can get it cheap then it might be a decent deal. If it was me I'd only buy a 4.150 crank if it had the 2.200 journals. I'd also prefer a 6 bolt crank and a high quality mfg.
If the crank you are looking at doesn't meet those specs then either build a 470 or a 512. Either will work with your TF240 heads.

Thank you AndyF....The other crank I was considering (mainly for a future build on my '84 D100) was a K1 crank which has the Chevy journals and 6 bolt flange. Not sure what a "good deal" looks like these days but it is half the price of my Molnar crank. Just getting ideas and trying to determine if it would be worth it to purchase one now..... I pretty much follow what other builders have done successfully, but not seeing much with the 4.15 stroke combo other than the 440 Source one. Thank you for replying - You guys may not realize this but your input is extremely important. You are one of the few that I pattern much of my build on. Thank you again. <><

 

[AndyF]

I'm not sure if K1 is still making that crank or not but I wouldn't have any problem buying a K1 crank as long as it looks good. Just check it over for any damage to the journals. Half price is a good deal. You should never lose money on that deal as long as the crank isn't damaged.
The 2.200 rod journal is key since that allows you to use a lighter weight and higher quality connecting rod. There aren't as many pistons available for the 4.150 stroke but you might find some. If not, a semi-custom won't be too expensive since it should just be a slight change to the pin height.

I think you would use a 6.535 long rod and a 1.360 piston. Molnar has a 6.600 long rod which would work with a 1.300 piston. A 6.700 rod would require a 1.200 piston which is really short. I'd probably stay away from that short of a piston in a street engine.

I used a K1 crank a few years back to build a 427 inch SB Mopar. That was a fun build!

 

[Team Vintage]

I have done both 4.15 stroke and 4.25 stroke in low deck blocks with 6.535 chevy rods and Ross pistons and Venolia pistons. never had any problems with either combo at 13:1 and 14:1 nitrous cars. Ross made a shelf piston (flat top) for the combo @ 4.375 Bore. Each made around 800hp on motor.