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HP/Torque- When things start breaking...

Discussion in '6.9L IH & 7.3L IDI Diesels' started by Fision, Nov 20, 2020.

  1. Fision

    Fision Full Access Member

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    Generally speaking, Components have an:
    A) “I can do this forever:)” happy spot;
    B) “I can only do this for so long...:bail” tolerance, and a
    C) “l quit:angel:!”

    As it applies to our IDI engines and old Ford trucks, What have you experienced/read/heard?

    Some of the IDI components I personally haven’t heard of breaking from raw power: the crank, block, pistons..
    Perhaps that will change now that Wes is getting 400cc+ out of the DB2 fuel pump :Thumbs Up:cheers::popcorn

    So, what are some approximate “max capable” or “max recommended” power levels where we will need to start beefing specific things up?

    Some obvious starting places:

    Head gaskets, with and w/o studs.
    Connecting rods: n/a, turbo rods and psd (diesel world mag said 6-650 for forged psd rods).
    E4OD, what mods have you done?
    Clutches, which ones have you tried?
    Driveshaft, when upgrade? To what?

    What components would you start with?
     
  2. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    Wes has already taken care of those. At least the rods and block parts. And that was with a junkyard IP too.
    Head gaskets them selves don't seem to be a real big problem. Not always, but most times, the "head gasket" issues seem to spring from fastener issues. Head bolts do seem to loosen some with age. Studs can stand to have their nuts retorqued after a time running. The bigger issues with head gaskets leaking seem to be from either too much boost or the engine getting too hot while towing (heavy, when it's hot outside, with a turbo, running A/C all at the same time). Either way, the heads can actually lift up off of the block a few thousandths and then the gasket will blow out. Too much boost with head bolts is from too much pressure. The working hard can actually cause your coolant to start to boil. The steam has more pressure than the liquid coolant does so that lifts the head(s). Basically, stud the engine, use an intercooler, watch the EGTs, and watch your engine temperature.
    Rods. Wes says that the upper limit for N/A rods is 400 HP. I would stay well below that to be safe (around 350 would be my recommendation). I think that the magazine is on the low side for the PSD rods. I believe that Justin from R&D goes to way above the 650 HP with PSD rods. I'm not sure about the Turbo rods. I do know that they'll easily be able to handle the 450-500 HP that I'm planning to run on my future build.
    E4OD. To start out, upgrade all of the internals to 4R100 specs. That will take you a good ways (I have no guess on numbers). After that, you have to go with a custom built transmission like the ones from John Woods.
    Wes offers higher HP clutches and that's what I'll eventually be going with.
    I also don't really have any good suggestions on driveshafts.
    None of the above is gospel or set in stone by any means. It's based on what I've seen on here in the past. Any component can exceed these numbers or fall short. This is meant only to be a general guideline. Two things to mention here. 1: what you need to upgrade will depend on how much power you'll realistically be making (not what you want to make). 2: nothing that I mentioned above is inexpensive-speed (power) costs money. How fast do you want to go?
     
  3. Fision

    Fision Full Access Member

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    SO true! I appreciate your understanding and honesty. We’ve all heard of the guy who smoked 2 packs and drank a fifth of whiskey every day since he was 10 and was active till he was 100 when a train ran over him. But USUALLY...
    That’s an advantage we have with such a large forum- the input of many to build a larger data pool.
    I’m glad to hear your input about the con rods. I’ve got the turbo rods so hopefully they’ll never be a problem.
     
  4. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    From what I understand, they are fairly close to the PSD rods. The PSD rods (as Justin says on his web site) are for when you want to get the most that you can out of your IDI. If you're wanting to stay in what I would consider to be the mid range of a high power build, 350 to 600/650 HP, I think that the Turbo rods will be fine. I may be wrong on the upper end of this, but I don't have much info on that type of engine build. If you want to know the upper power limits on Turbo rods, I'd talk to either Wes or Justin.
     
  5. Fision

    Fision Full Access Member

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    Justin did a nice physical/dimensional comparison of the 3 rods (na, turbo and psd)-search
    Connecting Rods: 6.9/7.3 NA vs. IDIT vs. 94-00 PSD forged
    Each rod is significantly beefier than it's predecessor. The psd rod is also the only one that’s forged.
    That being said, I doubt I’ll ever find the limit of my turbo rods. They are beefy:)
     
  6. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    Yes they are. That's why I know that I won't over power mine. Mine build will be kind of on the conservative side for a higher power build. I don't want the biggest, best, most powerful truck out there. I don't want to win any drag races. I just want to be able to pull anything that I care to hook to it and be able surprise a few (maybe more than a few) PSD and Cummins guys. Truthfully, I learned a long time ago that no matter what, I'll never have the most powerful car, truck, dirt bike, ATV, etc. I'll never have enough money or the desire to spend it to get the most powerful one. I've also learned to be happy with what I've got.
     
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  7. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    6.9s:
    Head gaskets are the first limitation, 8-10 psi without studs is doable, they have held 15-18 psi without studs but will blow at that level. Studded the clamping force should have them good up to 30 psi without going to a 625 hardware. Bottom end is just at strong as the na 7.3 parts. All Ford idis have forged rods and cranks from the factory.

    7.3 na:
    Head gaskets again will be your first limitation, the stock head bolts will handle up 130 ft lbs before they stretch, at 100 ft lbs they can be pushed as high as 25 psi, 15 psi and below seems to be very reliable. Stud them and at 150-160ft lbs you pretty much don’t see head gasket problems, the rods will be the next weak link. We’ve been having na rods kick at 350-400hp ranges all year, I can think of 5-6 engines all recently I have seen overpowering na rods, so for a performance build go with the idit. A 110 pump in the low 300s for hp seems to be a reliable mark for the na bottom ends, 130s and larger are really pushing reliability.

    Idit:
    Again head gasket is the weak link, but same story as the na 7.3, they’ll handle a good amount of boost for awhile but studs basically eliminates that as a problem. Rods are so far not a weak link here, I think the idit bottom end could go as far as the psd rods, and the psd guys are pushing those into four digit territory with larger chargers to keep torque low. I did shatter a pair of idit pistons two engines ago in the shop truck but that was from putting the fire out with too much nitrous and a severe backfire that broke the ring lands off the pistons.

    And now we have clutch options up to 600hp for the idits, we plan to see how far the idit bottom end can support soon.
    9F8C2175-0986-44E1-B362-34DB9FBC2F60.jpeg 6C1AEE98-CE79-43BF-B531-D324B4DDF2E4.jpeg
     
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  8. Fision

    Fision Full Access Member

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    Thanks Wes!
    I’m glad to here all the con rods are forged; that corrects a longstanding misconception of mine.
    Please take no offense when I say I look forward to you breaking more stuff:rock::popcorn
     
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  9. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    So I see that the upper limit has been lowered to 350 HP. Not that it matters too much. 300-325 HP is still a lot compared to stock and will easily pull most loads up and down the road.
     
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  10. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    I'll bet that he's going to test stock limits and then use main studs and Justin's main girdle. That's my call.
     
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