Tom Telesco, working on GOOD pistons for the Nailhead!

Discussion in ''Da Nailhead' started by SpecialWagon65, Nov 17, 2013.

  1. gsgtx

    gsgtx Silver Level contributor

    ok 4.250 with a 401 yes if you can get off the self rings, was thinking 425,. Pontiac rods on the stroke crank will not work

  2. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Ah yes right, Pontiac rods won't work on a stroked crank, but can be made to work on a non-stroked crank with a 2.250" rod journal if someone wants to use longer aftermarket rods for a NH build that won't be stroked.
  3. 8ad-f85

    8ad-f85 Well-Known Member

    You can if you add material to the crank.
  4. telriv

    telriv Well-Known Member

    I've used rods as long as 7.100". On average I have built many with 6.850" rods. The cranks are made of 1030 steel forging. Haven't done it but am told the crank is strong enough to cut down to 1.88" Honda size. That would be a MAX stroke. I know someone in Ohio that didn't want to pay the big $$$$ for a custom forged crank for his blown 455 BBB. He used a "Nail" crank & I was told he spins it to like 8K RPM's + & it hasn't given up the ghost yet as far as I know.
    On average the pistons weigh about 750 Grams with a stock length rod & stroke. Don't forget forged pistons are heavier than cast pistons. We have a FORGED piston that's lighter than a stock CAST piston. The pins are the big saver at less than 150 grams. Stock pins are around 235 grams. With a lighter piston a shorter/stronger pin can be used. So we have a savings in weight over stock. Not a lot, but the lighter the assembly the FASTER it will spin up. Not that it will make any additional HP, although it should in theory because your using less HP to spin the weight. Called parasitic HP loss. These pins are made from 5100 steel. Being they are stronger & more dense than a stock pin if it were the same length they would be heavier.
    With a 6.850" rod the pistons are about 600 grams with the same pin. Stock stroke. So there's a BIG weight savings there.
    I don't like the idea of welding up cranks. I would rather offset grind them to achieve the stroke length desired. In my mind adding that much heat to the crank many times warps it. Yes, it can be put in the press & straightened back, but what does it do through the heating & cooling cycles of a running engine??? When the engine is together how do you tell if it's out of whack???
    And why would you use a cast Pontiac rod. It's not a forging like the "Nail" & not as good. Just using a longer rod will many times not be worth the added expense & negligible gain that you could feel in the seat of your pants. You'll still have to use ARP rod bolts in the Pontiac rods. And if you do find a set of Pontiac forged rods & the $$$$ that you will pay for them, by the time you rebuild them, install ARP rods bolts, lighten them, narrow them, etc. you could buy a NEW set of rods for less $$$$.
    I could type ALL night & not give ALL the info I'd like. Been a LONG day, time for some sleep.
    Will pic up this chat a little later.
    These are just my thoughts.

    Tom T.
  5. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Great thoughts Tom thanks for sharing them.

    This is the Pontiac rods I was talking about;

    These just need to be narrowed .029" and the Pontiac bearings will work just fine when using them. With your customizable NH piston line you can probably get the pistons with .980" Pontiac size pin no problem, or open the hole up to 1.00".

    The 7.100" rod is interesting, am I to assume that those are BBC rods and was the crank stroked the .050" for the 2.200" rod journal size?

    "1.889" Honda rod journal would be the max stroke" What about the 1.850" Honda rod journal size? I think there is a Nissan 4/6 cylinder rod that is 6.496" long with the 1.850" journal size that have a .866" wrist pin. Just another .039" more stroke, you sure? Would be 4.030" that's with subtracting .010" for indexing. That would take a lot off one side of the journal .390" more stroke might be getting into the oil holes by then or very close?

    Some people get to have all the fun! :)

  6. gsgtx

    gsgtx Silver Level contributor

  7. telriv

    telriv Well-Known Member

    Yeah, we used a set of Eagle rods that were longer. NEVER had a problem with the stock rods hitting the heads up to 7K RPM's. With ALL the same specs we had to double up the head gaskets as the Eagle rods were making contact with the heads at RPM's. From this experience WILL NOT use them again.
    Again, just my thoughts.

    Tom T.
  8. telriv

    telriv Well-Known Member

    Sorry, on another note. I need your specs guys. It has been well over a year since this all started. I've been informed that they WILL NOT hold up to their end of the deal if things don't start rolling. WE have to start sometime. So get out, bring the engine in the living room next to the fireplace where it's warm & start the teardown & measuring.
  9. 66BulldogGS

    66BulldogGS Platinum Level Contributor

    Hey Tom! Just a quick question. Did you get a chance to order the next set? When we talked a couple weeks ago I think I was set #5 or #6. Just curious if the order went in and if they indicated what their leads times were running. Not a huge rush, just curious.

  10. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    What do you mean by "rods hitting the heads"? Are you saying that the Eagle H-beam rods stretch at high rpm and the piston hits the head? Thanks

  11. whatever

    whatever Well-Known Member

    That's what I was talking about! Their material is not good, they do stretch a lot. That's why I said at least 0.050 in piston to head clearance.

    Exactly! On a Honda stroker with ~88 mm crank ("the old one" website) it was measured that Eagle rods were stretching up to 0.031 in at 8500 RPM. Keep in mind, that those pistons weigh like nothing comparing to Nailhead.

    I have some knowledge in chinese connecting rods, I'd say that there are many companies that sell "chinese rods", but most of them are from the different factories. I mean, SCAT has their own proprietary machining factory in China of cranks and rods (100% owned by SCAT), Manley and K1 buy rods from a chinese factory as well (200 rods min.). The source of Eagle rods is still unclear for me, but it's said that they buy only bulk forgings, the rest of the operations (machining, QC) are done in the US. (It doesn't help the quality much.) There are some factories which are not presented on the US market by a certain brand, though they do quality rods at low price.
  12. telriv

    telriv Well-Known Member

    Someone else with EXPERIENCE talking about what I have been informed of & experienced. We rough figured they were stretching about .020"-.025" plus. The reason for doubling up on the head gaskets. This is worse than using QUALITY aluminum rods on the street. With aluminum rods it's not so much about stretching but about growth with heat, not like in the old days.
    John, I HAVE put in the order, but I had one back out at the last minute & sent him his deposit back. Also, as I figuring the specs out on another set things weren't coming out exactly correct. So I'm now waiting to get the specs for these confirmed BEFORE they will continue.
    That's why I put up the post I did. I have 15 that have deposits & I NEED THE SPECS!!!!

    Tom T.
  13. 8ad-f85

    8ad-f85 Well-Known Member

    We're kind of arguing semantics here...

    Nobody would suggest using CAST or factory forged Pontiac rods.
    Eagle rods and 8500 rpms shouldn't be in the same sentence, there are better choices out there.
    They are a budget rod on the lower end of the scale. No pro considers them to be "good".
    They do fill a need though. They get by, they are cheap.
    I would suspect they do no further heat treating from their forged, half hard condition. I seem to recall they Rockwell tested fairly low, in the past anyways.
    All manufacturing co's have had to deal with Chinese sourced bar-stock and raw material problems.
    I haven't used them in a few years and won't, although I hear they are changing their QC.

    You can put a crank on a shaker table, thermally cycle it,'s a matter of doing what it takes for a particular project.
    These cranks are a crappy material for further strengthening processes. Even after all that, they have a finite life.
    I can't imagine even a welded stroker being the weak link without a new head.
    Anything run that hard should be periodically inspected anyways.

    These builds are fun to dream about, no need to over think things.
  14. m1nt55

    m1nt55 New Member

    Hi Tom, I am still interested in custom pistons but my engine is still in the states, it is probably 6 weeks away from arriving. So getting you specs just isn't possible. Once the engine arrives I will strip it asap and get back in touch with the specs. If it's too late to order, that's ok. The engine is a 425 and I'm looking to build an offset ground stroker. I already have your roller rockers and I am part way through porting a set of heads I bought off a 401 engine. When I have the heads done I will be ordering a roller cam from Schneider. Out of curiosity, what sort of flow figures are you guys getting over there? I am not yet finished and the best I can do so far is 264cfm intake and 183cfm exhaust at .600" lift and 28" test pressure (the industry standard here). I would love to know what the nailhead experts are getting and how far off I am. I've tried to get in contact with Mike Lewis but have had no success. Nailheads are unheard of here in Australia so any info you guys might be able to give would be greatly appreciated.
  15. Marty World

    Marty World Well-Known Member

    Good evening.

    Incredible numbers on the intake and exhaust flow.

    Do you have any pictures of the port work?


  16. m1nt55

    m1nt55 New Member

    Hi Marty,

    Really? Thanks! What sort of figures have you seen from port work on these heads? I am an engine builder/machinist and I specialize in high output race engines but given the fact that nothing was ever released in Australia with a nailhead in it, I have never had s chance to play with one until now. I flowed a chamber before I started and then after and the improvement was substantial but this isn't unusual if things have been done correctly. Yes, I do have photos but have no idea how to post them. I would love to know what flow figures (and test pressures) other people have seen. These engines would be capable of making so much more hp if the exhaust port was of a better design. Does anyone make aftermarket heads with s better exhaust port??
  17. Babeola

    Babeola Well-Known Member

    Here is flow chart including some porting by some of the best Buick porters around. Your numbers are considerably higher then theirs. I am not saying you are fibbing, but maybe your flow bench is a little too happy?

    Cheryl :)
  18. m1nt55

    m1nt55 New Member

    Hi Cheryl, thankyou so much for your reply, I've been after comparative flow figured for s while now and have never been able to get anything from anyone. All the experts from your neck of the woods seem to be very secretive of these engines.
    I have heard the main man for porting on these heads is Mike Lewis, I've tried several times to get in touch with him but have never had any luck. I noticed his name wasn't included on your list?
    Yeah, I know, age old story. It seems I have better flow figures so I don't know what I'm doing or I'm talking ****! Im not looking to start another war, I was just after some comparative results.
    I work for a company that is seriously involved in competition racing and my flow bench is tested and calibrated quite regularly buy an independent company so I can assure you that the figures I have are 100% correct and accurate.
    Something I will say is that I haven't treated these heads as the mysterious beast everyone seems to describe them as. I flowed them in standard form, recognized their weaknesses and tried to rectify as much of that as possible. My thinking at the time was, I know nothing about these heads, port until Im happy, if I hit water, chase another set of heads and start again. I've pressure tested the heads at over 75psi and I have no leaks.
    I would love to know what Mike Lewis is getting out of these heads
  19. telriv

    telriv Well-Known Member

    Mike is NOT getting those flow numbers for sure. 264 on the intake is about the best I've ever heard. But, & there's always a but, 264 with turbulence would NOT be as good as 242 WITHOUT turbulence. As you can see from the chart a larger intake valve is NOT the way to go. Up to .300" it's better, but over it's worse than a stock head. Removing the "Eyebrows" in the combustion chambers helps, but lowers compression. My CUSTOM FORGED PISTONS can overcome this problem. DO NOT remove the upward lip on the bottom outlet of the exhaust. This helps to direct the exhaust into the manifold. Best I've heard of on exhaust is 193. Don't know if this is fact or fiction. Approx. 3/16ths. to 1/4" can be taken out of the roof. Slimming down the guides & contouring also helps. Unfortunately because of the high nickel content of the cast iron the casting can be THINNER. This doesn't help as before you know it you will be into water. Do you have/use a sonic tester to check thickness??? This would be one of the ways to go. Core shift is EXTREMELY bad in the later year "Nails". Because of this just because you got away with a certain shape on one set of heads doesn't mean you can do the exact same to another set. I know we got better flow by spray welding the exhaust to where the port is ACTUALLY smaller which probably increased velocity. It appears the exhaust comes out, hits the roof & curls around & comes out in one of the lower corners.
    11/32nds. valves are a given. I have 11/32nds. cast iron guides in stock. Now you have a "Pandora's" box full of options. Every little bit helps when your trying to make a HP producer out of a low RPM torque producer. The "Nail" was designed to get the big load moving. It doesn't take gobs of HP to keep it moving down the highway @70 MPH with the A/C on.
    Just some more of my thoughts.

    Tom T.
  20. Babeola

    Babeola Well-Known Member

    Well, we know a 455 with well ported iron stage I heads flow similar to your Nailhead claim. A full weight Skylark (4000 lbs) will boogie down the track in the high 10s with these ported 455 heads. You should be able to do the same with roughly 25 less cubes using a bored over 425 if your claims hold merit. I say less talk: more time slips for true comparative results!

    Cheryl :)

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