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The Square Deal

Discussion in 'Builds and Fabricators Forum' started by duffer, Oct 21, 2013.

  1. Oct 21, 2013
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    As I finally get into my flatty bucket list engine, and I know more that a few of you will probably think there are more than a few loose nuts and striped threads in the gray matter, I would appreciate any relevent comments. The objective here is a long stroke, light weight engine with goobs of low end torque right at idle. I decided to stay with Gen I because everything else is already in-place for bolt up and even though this will not be inexpensive, probably a lot less than building an LS equivalent with similar characteristics.

    So here's the plan: 4.125" x 4.125" bore and stroke Gen I Chevy small block utilizing a Dart 9.325 deck aluminum block, Callies Magnum crank and 6.125" light weight I beam rods, and JE 242885 inverted dome blower pistons with 1.125 compression height. Wet sump oiling. Heads will be aluminum but haven't decided which, with the head combustion chambers will be sized to get me close to 10.5:1 CR. Induction will be borrowed from the 381 in the 3B which is the 1000 cfm version ProFlo2 EFI and also thinking my existing cam grind may work well with this (Comp Cams 12-488-8, 218/224 degrees @ 0.050 lift, 0.565/0.570 lift).

    I want this thing bullet proof but don't anticipate ever needing to run higher than maybe 5500 rpm and with most use from 500 to 2500 rpm. Therefore, I don't think something like Brodix heads are applicable and am sticking with the stock 23 degree valve layout.

    So far, only the crank and rods are ordered so still have some flexibility. That said, I will likely place the piston order by the end of the week. I want the pistons in-hand before I order the block. I am going to have Dart do the block finish work because they are set up to do the final honing at operating temp, something my local shop can not do.

    And last, not a single piece that has ever been in China is to be used, not that there are any 4.125" chinese cranks I am aware of anyway. No good reason here, just don't like buying stuff made there.

    OK, open season-shoot.
     
    fhoehle likes this.
  2. Nov 4, 2013
    jwjeep60

    jwjeep60 in process

    Sedalia Mo.
    Joined:
    Apr 8, 2008
    Messages:
    561
    missing some fine details:
    roller rockers & lifters?
    valve sizes
    valve springs
    headers & exhaust
    flywheel & pressure plate
    Balance tolerances
    (ya weird questions)
    biggest challenge is keeping it balanced
     
  3. Nov 5, 2013
    tarry99

    tarry99 Member Sponsor

    Northern California
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    I seen this a while back and had to think a little before commenting...........Open Season?

    That is an interesting combination ........4.125 squared is what 441 cu inches?.........and your going with a deck height that is plus .300 or 9.325 using a 6.125 length rod & a piston that has a compression height of 1.125 assuming those pistons are not out out of the deck?????........what did you figure for deck clearance?
    I run those numbers and get .0125 deck........Crank 4.125/2= 2.0625 + the rod length 6.125= 8.1875 + your compression height on your piston @ 1.125 =9.3125 ........block deck 9.325-9.3125=.0125 If I'm doing the math right hardly enough deck clearance for an aluminum block with a long stroke. Should be closer to .065 +.............I'm assuming someone did the math on the rods , crank and pistons already? Most times the long rod will give you fits in getting the pin moved up high enough and still have room for a 3-ring package without plugging the piston pin bores...............notwithstanding in a small block anything over a 6 in rod with the stroke like you have has a pretty low rod length to stroke ratio and real high rod angle which will side load the pistons.........

    Making more torque at low rpms is tough .......it just requires allot more rotating mass than a small block is capable of at low RPM's ...Big Block no Problem!.......... Your current EFI system will require some jetting with the addition of 60 more cubic inches and I like the 10.5 to 1 compression and since your at altitude I would even perhaps go a little higher if that EFI system has sequential timing.


    I guess if it was me I would really concentrate on the heads and induction system , and build a real snappy motor that would accelerate right off Idle and then cover up my torque needs with some low gears but that's me.

    Anyhow just thinking out loud .........
     
  4. Nov 5, 2013
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    Tarry, I ended up ordering custom JE pistons so I could get the exact compression height (1.137") and dish volume (21 cc) I wanted and could use a set of off-the-shelf heads with no milling.

    Those pistons will zero deck in the block with the entire deck clearence being the 0.041" compressed head gasket. Given this engine will be using some pretty stout Callies steel rods and probably not going to run much higher than 5500 rpm, I think 0.041" will be sufficient clearence. I really wanted to keep minimal quench height to minimize the detonation potential, and even though the pistons are dished, there is still a significant flat top area.

    I am ordering AFR's 195 cc intake runner, 65cc heads (pn 1095-the full CNC'ed version) and that should put my CR right on 10.5:1 with the .041 ' gaskets. The EFI is currently running 29# injectors and they will likely be sufficient, it isn't too big a deal to put in a bigger set if they are needed. The EFI is sequential. When I set the EFI up on the 381 I had to do a global increase in the fuel delivery and then "de-tune" the idle back down because the Edelbrock calibration was for a 350 and I will get to go through that same routine again. It may also be time to purchase a wide band O2 sensor for the EFI and a gage. The hand-held unit that comes with the EFI basically gives you three points> 14.7:1, 14.7:1, and < 14.7:1. Actual numbers would be far more useful. The EFI is already set up to use a wide band sensor. I just have to remove one jumper in the harness and change out the sensor.
     
    Last edited: Nov 5, 2013
  5. Nov 5, 2013
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    Yep, roller lifters and rockers (1.6:1), both almost for certain Comp Cams products.
    2.080 intake, 1.600 exhaust valves
    155 lb on seat double springs with 0.650 max lift
    headers are Hooker 9810's, 1.75" long tube
    Will use existing Hays 11" clutch but will need a new steel flywheel for the internal balanced engine.
    And yes, it absolutely will be completely balanced-all rotating parts. I do that on just about everything I build now anyway.

    When I made my first post, I didn't have the heads selected so couldn't post the details there. Here is a link to the selected heads.

    http://www.airflowresearch.com/product_info.php?cPath=24_29&products_id=94

    I could have gone a lot bigger for the same $ but that would kill the very thing I am most looking for in this project and that is some big low end torque.
     
  6. Nov 5, 2013
    Mike S

    Mike S Sponsor Sponsor

    Cameron Park Ca.
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    OK, you got the importance of intake runner velocity all figured out.

    Have you talked to the good folks at Comp Cams, and explained what you are trying to do?? They are good at making suggestions to make your life easier. Discuss with them using an intake profile with a bit later opening and a steep ramp may add a bit of velocity at part throttle, but will detract from full throttle flow. Keep overlap down too.
     
  7. Nov 5, 2013
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    The Dart block uses big block cam journals so I assumed from the start that this was probably going to be a custom grind job. Do you, Terry, or anyone else have a good contact with Comp Cams? I did an online Comp Cams inquiry and got a totally ridiculous response. It would have worked well at about 6 to 7k rpms.

    What would be great is to have them run projected torque curves on a few prospective grinds. The cam order is going to wait until the rest of the short block is together so I can get a handle on the cam/rod clearence. I should be able to use a regular base circle but want to know that for certain before ordering.
     
  8. Nov 5, 2013
    Mike S

    Mike S Sponsor Sponsor

    Cameron Park Ca.
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    Sorry, dont have any contacts with them, I have simply called the hot line in the past.
     
  9. Nov 5, 2013
    tarry99

    tarry99 Member Sponsor

    Northern California
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    duffer,
    At Comp David McCarver is pretty sharp.......go through the main switchboard..............Keep in mind a longer rod decelerates toward TDC and accelerates away from TDC slower than a shorter rod so Piston to valve clearance will be important during overlap as the piston seems to stall @ TDC. Also the longer rod will hurt some low rpm power as it reduces scavenging of the exhaust. Ignition timing can also be reduced because as I mentioned the piston seems to stall @ TDC and you can get away with less intake runner volume because of same...........I'm surprised that you even need a dish to keep it a 10.5:1 , but I guess with that long swept volume that would be the case..........Are you going to put it on the pump when your finished? Good Luck on your project. Terry
     
  10. Nov 5, 2013
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    Thanks Terry,

    I should have quite a bit to work with on this one concerning valve clearence. I don't expect it to be limiting on this engine.

    Would love to put it on a pump but that would entail a 180 mile (one way) trip. Mike's Off Road (local) has a chassie dyno and may put it on that but not sure the D18 would like WOT. It would certainly help polish the FI program.

    I will try to get in touch with David tomorrow, but being SEMA week, probably no one arround-even all the local guys are in Vegas. Nothing like a little 100% write-off fun.
     
  11. Nov 16, 2013
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    First of the puzzle page pieces
    [​IMG]
    21 cc dish, 1.137" compression height
     
  12. Nov 20, 2013
    Posimoto

    Posimoto Hopeless JEEP Addict Sponsor

    Minden, Nevada
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    Mighty purdy! Seems a shame to hid them in a block. ;)
     
  13. Nov 27, 2013
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    I received the rods yesterday. Ended up using Oliver instead of Callies but don't think they are in any way inferior. They were available through my engine builder, the Callies were not. Friday or Monday I will get the weights on both ends of the rods and maybe a pic. The total rod weight spread is 2.3 grams. The pins were good to less than 0.1 grams.

    I also weighed the pistons/pins yesterday. Not too bad, also within a couple of grams but want the balance job down to someplace around a gram so will still be removing metal. Should have the heads next week. Progress! And starting to get that "new car" excitement again.
     
  14. Nov 27, 2013
    tarry99

    tarry99 Member Sponsor

    Northern California
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  15. Dec 10, 2013
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    Ok, time to order the flywheel. Torn between a 30 lb or 50 lb version but thinking 20 lbs is a lot of extra weight and probably not worth the small extra benefit at low speed. Opinions? I'm running a 30 lb version on the 381 but it is an external balance and the new engine is internal balance so can't borrow it. That and I will repurpose the 381 and should keep the flywheel with the engine.

    The Hays numbers are 10-130 and 10-150.
     
  16. Dec 10, 2013
    tarry99

    tarry99 Member Sponsor

    Northern California
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    Your building that motor like a sprint car motor........already has a bunch of torque built in..............don't kill it with a heavy wheel......put an aluminum flywheel on it! ....Right off Idle it will be pretty snappy!
     
  17. Dec 10, 2013
    tomatolane

    tomatolane Lane

    Chattanooga...
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    Shes going to be a runner :)
     
  18. Dec 10, 2013
    tomatolane

    tomatolane Lane

    Chattanooga...
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    x2

    It helps the little oddfire, but you will already be screaming for traction with the little mouse motor :)
     
    Last edited: Dec 10, 2013
  19. Dec 24, 2013
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    Picked up one more piece of the game set yesterday. Not too bad a Christmas present.
    [​IMG]
     
    IRQVET likes this.
  20. Dec 24, 2013
    tomatolane

    tomatolane Lane

    Chattanooga...
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    Just YUMMY!!
     

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