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Head bolts, rod bolts and main bolts

Discussion in 'Engine and Drivetrain/Mechanical' started by mk1_escort, Sep 15, 2018.

  1. mk1_escort

    mk1_escort New Member

    Hey guys, I'm rebuilding my 302 Windsor and with so many different bolts on the market I just wondered what the difference is between them all? Is there a certain amount of strength bolt I should be getting or are they over the top for high performance engines?
    Just looking at ARP bolts.
    Engine is getting a stage 3 cam and extractors. Also thinking of putting a 625 Carby on it. That's about it for performance. Not chasing HP, just a little bit more than standard.
    Thanks for any information

    Sent from my Redmi Note 4X using Tapatalk
  2. Horseplay

    Horseplay I Don't Care. Do you?

    Not all bolts are created equal nor are all engines in need of high end fasteners everywhere. If this is just a stock iron block and heads set-up with moderate compression standard bolts are fine for the heads. Same can be said for rod and main bolts. In all cases though, new bolts should be used. Bolts stretch when torqued and used bolts can cause issues with proper torque.
    You really can't do any better than ARP products. I use them exclusively on all the engines I have built throughout. If I was on a budget and could only splurge in areas, I would start with ARP for the rod bolts followed by the mains and lastly head bolts. But again, on a predominately stock build they are not necessary.

    I have to ask, what are "extractors"? Not familiar with the term in this context. And forget the "Stage 3" mumbo jumbo. What are the cam specs? Worst thing you can do (and TONS of guys do it) is use the wrong cam in an engine. It sounds like this might be a fairly "healthy" cam which likely means it requires some very specific engine traits to perform properly. Namely, it probably needs higher compression. I can't suggest more strongly to discuss your entire application with a few cam manufacturers and get their input. Even better to talk to a reputable cam grinder as well to avoid the "one size fits all" approach most main stream large manufactures will take. I'd bet anything you are thinking of using a cam that is not only not right for your engine but one that will leave you very disappointed. Stock Ford heads leave a LOT to be desired without some serious work done to them when it comes time to stick them with a big cam.

    Share some more details on your engine build and maybe some guys here can share actual experience to help you build a winner.
    mk1_escort likes this.
  3. Horseplay

    Horseplay I Don't Care. Do you?

    A few other thoughts

    Be sure to chase EVERY bolt hole and then clean them out well with compressed air.

    Use a quality thread lubricant (like ARP's) on bolt threads and under head washers. Skipping this will give you poor torque results

    Make sure to use a proper thread sealer on any bolts that go into a waterjacket. Don't rely on a poor substitute like a silicone gasket sealer. It is not made to be used in such a way and will take forever to dry as it will not be exposed to oxygen. A quality teflon infused white thread sealer is much better.

    If threading into aluminum use a good anti-seize on the threads. I really like a copper variety.
    mk1_escort likes this.
  4. mk1_escort

    mk1_escort New Member

    Lol, thanks horseplay. I knew you would ask cam spec's. I laughed at myself when I wrote stage 3. I just couldn't find the cam spec's when I wrote it up. More just wanted to make sure that I get the right bolts.

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  5. mk1_escort

    mk1_escort New Member

    I will definitely post up more specific details later in the day as I'm busy with the family for a little while

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  6. camachinist

    camachinist Member

    Over the decades I used Milodon, ARP, some Mr. Gasket and some custom Lamalloy stuff for racing engine modifications. I even used OEM new Ford and FMS bolts. Some of the more recent engines were built with the FMS stuff.

    Clean, clean, chase with bottom tap, clean, clean, follow bolt/stud mfg's recommendations.

    Oopsie moment? Forgetting to put some #2 on some ARP rocker studs on modified 351W iron heads going on a racing 302. No problem, just a tiny bit of milkshake that puzzled me for a few races until the light bulb went on. ;)

    Think everything through, then check it again. Once it's buttoned up, things get hard and expensive. No rush. Your postings remind me of some of my Aussie friends. Been awhile but had some good times at Calder Park outside Melbourne. To tell how long ago they laughed when I used 'bonzer'.

    Anyway, no worries. The fasteners today are pretty evenly matched for most uses. For a street engine, it's hard to go wrong with any of the name brands if properly installed.

    BTW, I even used GM bolts in some of the early engines where I jigged and drilled the 289/302 rods for 11/32" GM rod bolts. Never failed in service and the engines ran into the 8000 rpm range at the track. Stock bolts. They work.

    Just to get you in the mood, heh, the good old days... remember Speedworld well. Never had the guts to run a stick car though. However, that's what nine grand on a 289 sounds like. Good little engines.

    Last edited: Sep 18, 2018
    c6fastback likes this.

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