Got ripped off. Looking for a new idea for the inside of the engine. Stroker maybe?

Slant 6 Engines

  1. armyofchuckness

    armyofchuckness The Flying Valiant

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    So in 2002, I had a 225 block built for my 1964 Valiant since the 170 died. I didn't know what I was doing then, but I did ask the guy to bore the engine 0.030" over and he charged me accordingly. I just started my engine breakdown all these years later and, surprise surprise, it's bone stock in there.

    So now I'm looking for something new to do. I read Doug Dutra's stroker article and that sounds pretty interesting. Anyone tried that?
    http://www.slantsix.org/articles/stroking/stroking.htm
    How does that affect the streetability of the engine? For reference, here's what I have so far for the car:

    1964 Valiant 2 Door Sedan
    - 225 out of a 1970s Dodge van
    - 904 Pushbutton
    - A/C
    - Power steering (Saginaw)
    - large valves (1.70/1.44) from engnbldr, porting job, with 340 valve springs, planed 0.100" off cylinder head
    - Erson 280 int/270 exh duration cam, 0.465" lift with lifters
    - Recurved distributor
    - Double roller timing chaing
    - Stock oil and fuel pump
    - 90 Amp Alternator
    - HEI
    - Offenhauser 4bbl intake and Edelbrock 500cfm 4bbl with electric choke
    - Dual Dutra Duals into a Y-pipe and single 2.5"
    - 8.75 3.23 Sure Grip

    TBD: - 2600-3000 RPM stall converter

    I'm also doing some serious suspension upgrades, but the only one I think is even slightly relevant is I'm moving the battery to the back. The car is being built to be quick and handle well on the street.

    So with that configuration, what would you do with the block itself? Is it worth looking into boring it out still? Doug's article seems to imply not, but I know many people have said they bored theirs 0.060" over and seemed happy with the results.

    Thanks for the help!
     
  2. 65 Dartman

    65 Dartman FABO Gold Member FABO Gold Member

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    I'm no slant guru for sure but your engine build sounds pretty stout for a street motor. Does it now need over boring? If so, I would probably start with 30 over - that's what my 65 engine needed to clean up the bores. Like the article said 60 over won't provide a lot. You might want to check the block deck to make sure it's truly flat. Also consider decking the block (definitely run the numbers so you won't end up with an unmanageable compression ratio - my block got decked 90 thou and head cut 10 just to clean it up. IIRC you're also a member over at .org - ask the same question over there with the same info you provided here. As over here you'll get 10 different opinions from 10 different people
     
  3. Charrlie_S

    Charrlie_S Well-Known Member

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    Chuck, In my opinion, stroking the slant six is not cost effective. Even boring just to get more cubes, is not the way to go. However, with the amount of cylinder wear you will find in just about any slant six motor, boring will be necessary for good ring seal. So you might as well go as large as your budget will permit. Generally it will cost about the same whether you bore 20, 30, 60. after that the price will go up. Selected slant blocks have been bored to more then .150 oversize.
    If you still have my number, give me a call, or send me a PM and I will give you my number.
     
  4. armyofchuckness

    armyofchuckness The Flying Valiant

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    Thanks, Dartman. Good point. I'm afraid when I got over eager on my cylinder planing at 0.100" I may have shot my chances of doing anything more than flattening the deck. I may end up not doing anything to the innards depending on what opinions I get back from FABO and .org (I posted there too).

    Just figured while I have the entire engine apart, now is a great time to take stock of my options.
     
  5. armyofchuckness

    armyofchuckness The Flying Valiant

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    Thanks, Charlie! I do have your number. I just PMed you about when I can call and with my updated number. My old cell number still works for receiving calls, but my outgoing calls show a different number, so I wanted you to know I wasn't a telemarketer when I called.
     
  6. 6pakattack

    6pakattack Well-Known Member

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    I went .104 Over on my last /6, and it's still happy to this day !!
     

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  7. armyofchuckness

    armyofchuckness The Flying Valiant

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    That's so cool! Would you mind sharing what pistons and rods you used? Is that one of the older forged crank blocks or a cast blocks? I'd love to be able to copy something like that!
     
  8. vitamindart

    vitamindart Well-Known Member

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    if possible I would mill the .100 off the block not the head.
     
  9. Darter6

    Darter6 Well-Known Member

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    A.O.C, Charrlie will guide you down the right path.I hold him in very high regard on slants. As stated you may have to bore to clean up the cylinders.That case it means new pistons and the cost for .020-.060 pistons will be about the same.Now if you ever saw a stock slant piston, they look like beer cans. Aftermarket pistons to me are much better.It sounds like you have the head done already and shaved .100. If that is the case only take as much as needed to clean up the block and get it straight.Last but not least find a shop that is trustworthy.Again Charrlie sure knows who to trust in your area.
     
  10. armyofchuckness

    armyofchuckness The Flying Valiant

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    Great advice. I had a nice phone call with Charlie last night and I think I have a good plan moving forward. I've been out to Charlie's several times, so he's familiar with me pestering him!
     
  11. Bill Dedman

    Bill Dedman bill dedman Legendary Member

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    In my opinion, the best "bang for the buck" comes from turbocharging a slant six.

    The cylinder head is the main obstruction to making good power, naturally-aspirated, as it has unusualy small valves and ports, and even with a professional port job and bigger valves, doesn't work very well on a 225 motor. It is, however, a GREAT head and has appropriately-sized valves and ports for a 170 motor. But, a 170 is a fantastic race motor with revs to the sky, it's just not big enough to be very practical on the street.

    A turbocharger will let the engine sidestep the breathing problems it has and is a good alternative to hopping up a naturally-aspirated slant motor, I think.

    But, it's not cheap, nor, is it easy.... There are a couple of expensive items that take it out of the picture if you're on a tight budget, but, if you have the coin to spend, I think it's a far better alternative than building a slant any other way.

    My 15 pound boosted slant makes a little over 350 horsepower, which is probably a little more than what a full-race slant, naturally-aspirated could make. And, it has excellent road manners (idles like a stock motor and has tons of low-end torque.)

    If you have any interest in a 10-pound-boost motor (you can use stock pistons and rods...) just ask here, and we can fill you in on the specifics.

    OR, just ask Charrlie; he has forgotten more that I'll ever know about turbos (and, slants in general...)
    seriously.

    Good luck! :cheers:
     

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  12. pishta

    pishta I know I'm right....

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    Build what you got, that convertor isnt the best for a stroker, neither is it for a turbo. It sounds like a fun N/A motor. May not even have to bore it, just rings? turbos make torque low so you dont want alot of slipping in the convertor, and that cam sounds made for your convertor and valve work so I'd run with it. Headers help.
     
  13. jbc426

    jbc426 Well-Known Member

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    Just my experience, but I had a Doug Dutra built Slanty with big valve heads etc. Ran it for years. It was impressive for a slant. One day I was just tired of it, sold the motor and trans and swapped in a tired junkyard 5.9 Magnum with EFI and a 727. I drove that for a year or so, then built a 408 stroker for it and hooked it up to a 4 speed overdrive automatic with lock-up converter.

    Both the 5.9 and the 408 get better mileage than the slat did, have WAY more performance and pretty much bolted right in. I'd never go back to a slant no matter what kind of unlimited budget build the slant 6 was.
     
  14. Bill Dedman

    Bill Dedman bill dedman Legendary Member

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    That's because you tried having a naturally-aspirated slant six AND high performance. The strangulated cylinder head defeats all attempts to make a "breather" out of a slant. The only way to get impressive performance out of a slant six is with nitrous oxide, a supercharger, or a turbo. They NEED help in the air-flow department. The turbo motors I have seen that work well are in early A-Bodies that have (unladen) vehicle weights around 2,800 pounds. Tht puts them through the quarter-mille in generally, less than 11 seconds, like this one: [ame="https://www.youtube.com/watch?v=7QzUfV8iTpQ"]Turbo Slant Six 10.74 @ 127 mph 7-19-10 - YouTube[/ame]

    Those turbo slants make over 500 horsepower and idle like a stock motor.

    But, trying to move nearly 3,000-pounds with a naturally-aspirated slant six is probably not gonna work well. The turbo route is neither cheap, nor easy, but it's a viable alternative to swapping in a V-8 into A-Bodies for increased performance.

    There's a picture of my '64 Valiant with a turbo slant... :wack:
     

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  15. jbc426

    jbc426 Well-Known Member

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    I have seen a clean turbo /6 Duster at the Mats in Vegas, but yours is sweet looking too. Did it make those 10 second passes on pump gas or do you have to run race gas to get the boost dialed up to that point? 500 hp out of a Slant sounds expensive and high strung. I think my convertible was well over the 2800lbs mark with the Slant as well, probably closer to 3350lbs.
     
  16. barbee6043

    barbee6043 barbee 6043 FABO Gold Member

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    this subject of the slant has been cussed and discussed here more than a little!

    I think the allure of the slant is basically the hotrodder thing, where we like to take a free engine most people toss, and make it run, maybe not that fast! yep it can be make to run like a striped a-- ape , for the right knowledge and $$$.

    we like to be different. we like the longevity of it. mileage. ( 30 mpg with 4 spd OD, done it). lot of us just like to tool down the road in our old slants! I have v8 cars when I want more seat of the pants thrills.
     
  17. Johnny Mac

    Johnny Mac www.blueprintengines.com FABO Vendor

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    I'll throw this out there as i don't see it refuted when mention above...

    you do NOT drop a block off at the machine shop and say "bore it .030 over" and then go out and purchase your pistons at a later date, after you have the block back. Aftermarket pistons are typically oversized .001-.005 (from publisher bore) and you then match the finish hone to those specific pistons. You should drop off the block WITH your desired pistons, so they can me bored/finish honed properly, to the correct size.
     
  18. Bill Dedman

    Bill Dedman bill dedman Legendary Member

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    That car in the video is not my car; wish it was... My car runs on race gas and is a lot slower than that one right now, because it's relatively new and I am bringing up the boost in increments. I have run 12-flat at 112 (numbers extrapolated from eighth-mile timeslips) at 15 pounds of boost. The car in the video also runs on race gas, but is using 28 pounds (!) of boost.

    It weighs 2,800 pounds without a driver.

    My '64 Valiant weighs 2,680.
     
  19. 273

    273 Well-Known Member

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    The advantage of stroking is low speed HP which needs less gear stall and better street manners. Since torque is proportional to engine size most mid performers get around 1.2:1 torque to cid race engine can get higher.
    Everything pretty much mathematical related. Using percentage differences can get you in the ballpark.
    The quick and dirty way is the multiple old cid with (rpm/gear depends what your comparing) and divide by new cid. Eg... 225 x 5500 ÷ 240 = 5156 so your peak power and powerband moves down 344 rpm not much for the money and gearing would be 240 × 3.23 ÷ 225 = 3.45:1. So stroke would be similar to moving up a gear step.
     
  20. Bill Dedman

    Bill Dedman bill dedman Legendary Member

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    The 500 horsepower turbo slant sixes I know something about have 8.51 compression, one 4bbl carb and idle at about 500 rpm very smoothly, very much like a stocker. There is only one thing about them that could be considered "high-strung" and that is their requirement for high-octane fuel. They cannot make that kind of power on pump gasoline; they will have detonation problems because of the high cylinder-pressures that exist due to the 28 pounds of boost they run. But, they don't exhibit the kind of driveability issues that exist in a naturally-asporated motor that has a long duration cam and 12:1 compression with the aggressive spark advance curve that goes with it to make it a "full-race" engine... high-strung, if you will.

    On the weight issue, mycar is a 4-door sedan with the following mods, that helped lighten it: No gas tank; fiberglass hood; no front bumper; no back seat, lightweight fiberglass front bucket seats, aluminum front wheels; no exhaust system; no heater; manual steering and brakes.

    Those mods have made the weight 2,680 pounds. My street-driven, 340 powered 1964 2-door sedan weighed 3,105 for comparison. Convertibles tend to be a little heavier.
     

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  21. RustyRatRod

    RustyRatRod Weenie idiot loser. FABO Gold Member

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    Keep in mind the 225 that Dutra talks about is NOT a stroker.

    It is simply a long rod 225. There is no change in the stroke whatsoever. I seriously doubt you'd feel a lick of difference in the butt dyno all other things equal between the long rod version and the stock rod version, so really, it can end up being a colossal waste of money.

    Especially considering you can mill the head .100" or more and the block just as much to gain compression. That's really the biggest benefit of the long rod engine. You use the 2.2 4 cylinder piston with the 198 length rod to help get compression up.

    The non turbo piston will get compression easily into the 10:1 range, so you will have to be careful since the slant is not a quench engine.

    If I were building another slant, I would simply build a stock bottom end 225 and mill the block and head to get compression up.

    You will come out much cheaper in the long run and have the same result.

    Bill Dedman also makes excellent points about turbo charging the slant. They respond very well to that.
     
  22. Dizzydean

    Dizzydean Well-Known Member

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    Just to add my 2c I opened my 71 block .80 and decked it .010 but I did the same head work you did, used the Aussie long runner intake with the edel 500 and Clifford short headers. Sounded like a V8 while idling and had lots of power for what it was.
     
  23. armyofchuckness

    armyofchuckness The Flying Valiant

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    Thanks! This is all great advice. I do appreciate the idea of turboing the Slant, but it won't work with the cam I have right now, and I really don't feel like losing that investment. Also, I'm pretty sure I won't have room for the turbo with air-conditioning. I've looked at just about every turbo build out there, and haven't seen someone that has done both.
     
  24. Bill Dedman

    Bill Dedman bill dedman Legendary Member

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    Chuck, if you really want the benefits of turbocharging, you could use a stock cam; turbos work well with a stock cam. That would allow you to sell the aftermarket cam you have and get some of your money back.

    As far as the packaging goes, there are LOTS of turbocharged vehicles that have located the turbo at the rear of the vehicle, just in front of the back bumper. That seems to work fine. That would free up the engine compartment for the A/C compressr and lines...

    If you REALLY want the benefits of a turbo, there's a way...

    My '64 Valiant has run 12-seconds flat @ 112mph, turbocharged with 15 pounds of boost. That would be acheivable with stock pistons, and is about 350 horsepower.

    You pays your money and, you takes your choice...:coffee2:
     

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  25. armyofchuckness

    armyofchuckness The Flying Valiant

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    Lots of food for thought, Bill. I appreciate the advice!
     
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