I'm considering a stroker kit for the 390 in my 70 crewcab. What do you guys think of this one?

http://cgi.ebay.com/ebaymotors/FE-39...mZ180174879752

 

Better choose wisely, there was only one kit in that whole list with compression ratios low enough for a pickup truck application-------and add $80 for that one--plus another $200 for balancing, then figure more to have the block clearanced. Then you have to ask yourself is 50 more ft/lbs worth an extra $2000 ? A stock 390 already has 425 ft/lbs if you build it using the 4 bbl late 60's 10.5 to 1 car specs.

 

I would contact Barry R. who is a member of this forum.

www.survivalmotorsports.com

He is an Engine Masters competitor, and will have the information you need to make an informed choice.

-Scouder

 

Free, it doesn't look too bad a first glance. Do we know who made the crank and the rods ? The pistons are from Probe, no problem there, thats a brand we have heard of. It sounds like the asssemblies are balanced already, and there is no need for clearancing in the block. I'm not sure where BD457 came up with his 50 lb-ft gain idea. I think it will be much greater than that. Some of Mercury's testing in '65 showed an 80 to 100 lb-ft gain in torque just going from the 390's 3.784 stroke to the 410's 3.984 stroke. Mercury was looking for low rpm power to move around the heavy luxo-barges of the day. They found it easily in the new 410. If you stroked a 390 out to 450 or so inches, the increase in displacement will yield a nice gain in torque, and right from idle on up, right where a pickup truck would like it. The extra inches will mean the engine will run out of breath at a lower rpm than stock. Choosing a proper cam will let the engine breathe enough to run as much or more rpm as stock. Do you already have a good 4 barrel intake and headers ? You wouldn't want to strangle that large engine. You could also give Barry R @ survival a call. He has alot of experience with this stuff, you might like his 'tugboat' idea. Where in Alberta are you ? Are there any E85 ethanol stations near you ? That would allow you to utilize a bunch of extra compression. DinosaurFan, on work's old 'puter

 

And where did you get Merc figure of 100 ft/lbs? The Motor Repair Manual lists the 410 Merc as having 444 ft/lbs, that's only 20 ft/lbs more than a 390 with the same parts. I was making a "guesstimate" on 50 ft/lbs, based on the difference in the figures above. And you'd better go back and reread that auction, it clearly states the kit needs further balancing.

 

I being a fan of building 410's and a few 454's over the last 36 years this brought me great intrest. Thanks for posting.
I really like the forged crank, I wonder what country they're made?
With LA Kriptonite out of business this looks like a first choice crank so far. I just can't stomach spending my hard earned money on a Made in China crank no matter how good they are, it's just not right.
If the pistons have a zero deck pad area like KB 150's with some aftermarket high flowing BlueThunder heads for a tight quench you should make a strong torque monster at 9.6 cr. Add MPI on a 496" oh I can't even think about this as I want one, hell sell the wife and kids on ebay.

 

Carl the cranks are forged overseas. It's the same forging that's been out for a while.

 

Geeezus....I know why now..I quit going by the motor manual for HP and TQ ratings at the age of 10.....and yes they actually made them back then...

I suppose it also says that a 426 Hemi with 2 4's only makes 425 hp also...Instead of over 500hp..

RJ

 

Yep and 490 tq.

 

Would this forged crank be Scat's?

 

I thought Scat's FE cranks were cast?

 

Months ago I ran across some vender selling FE stroker kits that gave you an option for cast or forged cranks.
I'm thinking this thread it's Scat's forged crank.
My question is what are the compression ring widths, 1/16" are find and dandy for high rpm's but what about for going the distance like 250K miles on a daily driven street motor? I would rather have 5/64" wide compression rings.

 

No it's not Scat. I'm not sure exactly what the brand is?? X maybe? I think Doug at Precision Pumps along with another person contracted these to be forged. I'm not sure who what or where. But that's the story I remember. Barry R might know more. I think it's a crapshoot quality wise for a small run of stuff being done overseas. Barry has said they were out of spec and he has his crank guy go over them before he lets them out the door. That's why his are a little more. Well worth the price of admission to me. There was a company named Condor that was selling them on ebay stating they where the wholesaler on these. Who knows?? LOL. I think Scats QC is better and their stuff has been pretty good overall. If there are inferior parts out there lately is not much mention of it. I get around quite a few forums. But Scat still has yet to do a forged FE crank. Those are all still cast far as I know. I wish I could afford better than what I have. But for now it will have to make due. I blew my whadd on the block,heads and intake. Maybe Russ can dig up a few mason jars and send them my way?

 

It's common knowledge that the HP motors back then had their HP figures fudged, but why would a run of the mill passenger power plants figures be as well ? If you're not going to prove your case, Don't knock what you have no way of proving otherwise. The Motor Repair Manuals have a wealth of knowledge in them,(one of the only places you'll find the torque sequence for a 427's cross bolts, but I guess that stuff's wrong too?) just because the factory's published HP/TQ figures don't agree with you means zilch.

 

Geez....badad.....I like how you dont read things right....Did I say a damn word about Tq specs or Sequence ?? Shoot even a broken clock is right twice a day!!! Wake up and smell the coffee......

We all know the Hipo's were done that way for insurance purposes..... and then they went from BHP to net hp once the insurance co. figured that one out... and NO-one writes a Perfect book!!

So dont believe everything you read is all.....

BTW hows your build coming along??

RJ