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318 Poly dragster engine

Discussion in 'The Hokey Ass Message Board' started by Dolmetsch, Jul 21, 2012.

  1. This exotic fixture is my new rod balancing fixture. I have had several in the past but when I sold the machine shop equipment that was all included. This is my latest made in about 10-15 mintes. In fact waiting for the paint todry is the hardest part of the project. For V8s big end and small end must be weighed seperately and this fixture does it well. The Big end hangs on a stiff wire made from a real coat hanger. The wire sits nicely in the parting line of the cap which is the centre. The height is adusted with the wedge shown in the one picture because the rod must be level exactly for proper weighing. Later rod is reversed and big end weighed. This small end , Just popping it on for a photo shows 211gr. That is somewhat typical. How do you know it is working properly? Results MUST be repeatable and you MUST get the same figure each time otherwise the whole exercise is pointless. So far so good with this one. The scales I use are from Philipps and come from the cooking dept at Walmart. ($39.00)
    I used to use more exotic expensive ones but they went up or down in 2 gram steps and cost a lot more. This little wonder is in one gram steps and has been here for probably 10 years. Still works great. Tomorrow after a good nights sleep I will get to serious balancing of the rods.
    Intial run through looks good. Small ends very close as is. Big ends need a bit of work but not an excessive amount.

    Attached Files:

    Last edited: Aug 13, 2012
  2. Done balance. Not too bad really. Newer Rods seem better balanced then 1960s and 70s stuff. Sent cam for regrind. Grinder will call probably today or tomorrow. Have used him for many years for this type of stuff.
    Took rods and pistons to hang at my pals shop. He came up with a set of Total Seal Race rings for 4 inch bore that will fit these pistons. Only good for something like this because any race engine would be bored immediately so standard bore ring set is not normally used. He didnt say how he got them . Just threw it on the box and said "there you go." Like I said this engine seems to be building itself.
    I should explain. This engine was 3.91 bore. It is now 4"
    Last edited: Aug 14, 2012
  3. BuiltFerComfort
    Joined: Jan 24, 2007
    Posts: 1,620


    Looking good Don - I appreciate the detailed posts too.
  4. Thanks,
    Grinder called tonite. I told him what i needed spec wise and gave him some wiggle room. I should know by thursday how it came out. Interestingly he comes in his Dad's shop at night and works by himself all night uninterupted. I dont know him real well but I have dealt with his Dad on many special projects over the last 40 years including the NASCAR Returns to Lemans driver practice car engine. He did that cam for me from a private master he made for me almost 30 years ago. (I also use it in my Max Wedge Street Cleaner.) He hard chromed and ground the crank for that motor too. (400 Dodge)

    Attached Files:

    Last edited: Aug 15, 2012
  5. Even though this is a back burner project it seems to be building itself. I never have had one go like this. I hope it is a good sign.
    Pistons are hung and rings are weighed. I now have all the weights for balancing the crank but that will have to wait a couple of weeks. August's budget is used up. Balance is scheduled for Septembers budget. I try to make sure Cars are my hobby and not an addiction.

    Attached Files:

  6. just testing my math here - 4" bore with 3.31 stroke ends up at 332.5 cubic inches. Let's call it a 333 poly then. Being oversquare like that, with the breathing you are opening up, this thing should be a monster! What primary diameter and length of header are you going to use? Collector diameter?
  7. I will be running 34 inch primary 1 5/8" collector will be 3 inch and probably 9 inches of functional pipe. I reserve the right to shorten primary to 32 after initial testing. depends how I like the pull in the traps.
    Secret formula for all v8s with a 4 inch bore is stroke X 100 +2. (my own)
    Actual size not using that terribly inaccurate figure known as PI is as you said 332.75827.
  8. Cam is not back yet.
    More when it arrives
  9. GregCon
    Joined: Jun 18, 2012
    Posts: 689

    from Houston

    318 Poly's were not by any means pigs. In fact, they moved quite well. A 318 Poly would put any 318 LA on the trailer, no contest.
  10. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    from BC

    Scary how many "reputable" machine shops do...
  11. Yes, I have never been motivated by what others do. So far it has served me well.
    The idea of the pinch is to pull the sides in so the rod bore cleans all the way around. I found early that it took very little extra cut to get a clean housing bore anyway. It is my opinion and I may be alone here, so be it, that the pinch puts stress already into the rod that would otherwise not be there. Rods dont need any extra stress. It also makes them hard to get apart even just after resizing. My way doesnt have that problem and I can say that not once ever in my career has a rod I resized ever spun a bearing. One might think I was just lucky but I think it was because of careful machine work. I am anal about rod resizing and want it ON SPEC. Not just in the window so to speak. It is for that reason I much prefer to do my own. Otherwise I often have sleepless nights worrying even though they are within spec technically. I have even resized new ones because I wasnt happy about the tolerence window. I know that is probably crazy but tis how I are.
    Last edited: Aug 27, 2012
  12. TR Waters
    Joined: Nov 18, 2006
    Posts: 1,439

    TR Waters
    from Vermont
    1. Early Hemi Tech

    "No I dont dyno I weigh the car and run it at the track Far more accurate and a lot cheaper. If you want the one I just talked about was exactly 4150 lbs with driver and turned 119.11 mph.
    Why dont I dyno? # 1 I dont have one. # 2 I am not paying anyone $600 of totally unproductive time on their dyno to tell me something I can find out at the track in 10 or 11 seconds with greater accuracy."

    I dont mean to be a dick, but I am sorry. That is just about the most ridiculous thing I have ever heard.
    Please explain how you will know the exact curve for both peak hp and torque, timing, as well as bsfc and a/f ratio during the operating rpm range? (you know....the things that lead to optimum performance) The answer dont know. It is all a big guessing game.

    Yes, it takes so many hp to move a given amount of weight a certain speed. (not including the variables) That still does not give you any of the above information.

    The toughest part of using a dyno? Explaining to people why your 500+ hp engine only showed 375 on the dyno.
  13. I dont mean to be a dick, but I am sorry. That is just about the most ridiculous thing I have ever heard.

    You are probably too young to understand so I will give you my classic answer I have given my competition over the years.
    "So beat me" (Especially $ for $.)
    I have no intention of getting into a discussion like that. Perhaps a search of my past motor stuff would surprise you. If you want to dyno. go for it.
    Frankly Scarlet....................... you know.
    I would suggest you sit down though calm yourself and think it through.
    A car will NEVER EVER go faster then it has HP to push it. In your example which is a good one and is typica,l lets say the weight Hp 1/4 formula says the 500 HP engne should go 125 mph and it is only going 113 mph.That is pretty obvious that it isnt making the 500 HP. And that is an extreme example. It is just as valid at differences of 1 mph. For instance a header leak at the centre port gasket on a 440 will immediatley showup as a loss of almost 2 MPH, just like it would on your Dyno in hp. Likewise a car with 500 HP will NEVER turn the MPH in the quarter a car it would with 505 hp. (unless you had a tailwind)
    I dont have a dyno. I dont particularily want one now. I have had a very sucessful career. Motors and copies of my motors from my book and ones I have built or helped with are spread throughout NA and Europe. No one is phoning complaining . I am now retired and trying to have a bit of fun. The nearest Dyno is about 60 miles from here and not really performance experienced. Next one is over a hundred miles away and has only bowtie experieince. The Dyno does not make HP anymore then the flow bench makes airflow. It tests it. If the builder doent know what to do the test doesnt do it for him.
    Have any of my engines been on a dyno? Yes a couple. Sometimes a chassis dyno after the fact. One engine produced 110 HP over what the customer requested. If he was on our board I think he would speak to you to go gently. Many have built my most famous combo and i have letters here of performance exceeding their wildest dreams.
    In my 46 years of racing I have put more dynoed mtors on the trailer then some have had hot dinners. I had a engine in the top five for over 8 years at the local track and a track champion here and there. So I am not the least intimidated by "My motor dynoed at whatever." If I had a dyno I would use it especially in the winter. I dont and have learned how to read a time slip (MPH) against weight. It is an old and fairly reliable method and NEVER overstates HP.
    If it doesnt suit you, fine.
    Here we do the best we can with what we have.
    Now its turn for my parting shot. (If you give it you have to take it. )
    If we were racing $$$ for $$$ , you against me I assure you, you would have your hands full!
    Now lets get back to the poly engine can we?
    Don Dulmage
    Dolmetsch Engine Development
    Belleville Canada
  14. What's that saying "You don't race a Dyno" - You go Don . . . :)

    No Cam yet I take it . . . I really want to know how this thing runs! I am considering driving up to Belleville to see it . . .
  15. RichFox
    Joined: Dec 3, 2006
    Posts: 10,020

    Member Emeritus

    I have dynoed two engines that I wasn't getting results with in my Bonneyville/Dry Lake car. It was helpful for finding nozzle placement and such in a comparatively short time. But people are always asking me why I have not dynoed my current engine. Why don't I know the horsepower numbers? My answer is I only care about numbers on the timing slip. My Howard head GMC was one I ran on the Dyno. Several people liked the way it ran on the salt and came around to look at it. They asked how much power it made. Since I knew the answer I told them. They never liked the truth. So I added 100 hp to the number. They liked that better but still not happy. So I added another 100 HP to my answer. Now the spectators were happy. So I stuck with that number. In the interest of full disclosure Both Dynos I used belonged to friends of mine, and as such I didn't have to pay to use them. If you are paying for Dyno time you better be ready with a plan and parts to try. If you just want to set your timing and mixture and have a bragging number that's ok to.
    Last edited: Aug 29, 2012
  16. No the cam still isnt back. Im preoccupied at the moment anyway with the /6 rail. Falll race is coming up and I want everything right. Also went back writing for CP magazine so that took priority for awhile. I am still at the cut and try stage so to speak. Once I assemble the short block after I am sure it will all work out with the cam and pistons maybe we willl do just that. Right now there is not much to see.
    I sent the cam in with a John Deere crank at my pals machine shop. The crank had to have one journal built and the thrust repaired before grinding. I expect when it is sent back my cam will come with it. In the meantime I have enuf to do.
  17. 73RR
    Joined: Jan 29, 2007
    Posts: 6,848


    The dyno provides feedback on changes in very short order, thats why we do it.
    Header gasket leak stealing a couple hp? Ten minute fix on the stand, two hours in the car.
    Ignition timing changes? Change, make a pull. Or, change, drive the quarter mile, and hope you do everything the same.

    Everything that can be done cheaper by driving the ¼ can be done faster on the stand and the stand doesn't care about the driver or the tire pressure or the traction or the optimal gear changes.
    If you have a ¼ mile strip next to your shop then you are blessed, use it.

    My 2¢

  18. I do. About 15 minutes away.
  19. RichFox
    Joined: Dec 3, 2006
    Posts: 10,020

    Member Emeritus

    Al moved to Placerville and took his dyno with him. I would have to drive by Sacramento drag strip to go to Al's. I don't have a dyno next door either.
  20. Hi Don,i'm 65 and have been involved in different types of racing since I was 20 never used a dyno until 5 years ago when a customer wanted to test a motor we built against one he bought from a winning team, some of the things I had been doing for years as it worked in the past actually lost power, our motor made 20hp more and found another 15hp by changing things. he won the championship, he had a really good team. somethings that work on a dyno don't always work out on the track something called drive-ability
  21. Truckedup
    Joined: Jul 25, 2006
    Posts: 4,662


    Rich ,not to get off the topic here,but what was the actual HP of that Howard head GMC,302? I suspect they were wanting to hear 100 HP per hole?

    Dolmetsch;do You have a target power level or track time in mind for this build? Or just do the right stuff and see what happens?
  22. RichFox
    Joined: Dec 3, 2006
    Posts: 10,020

    Member Emeritus

    I am not getting back into that mess. Lets just say it set a record for me and a few for the Salt Circus Roadster to whom I sold it. Much less than 100 per hole. I stopped at 500 hp.
  23. It is my goal to get 500 HP. I fully relize it may not be possible but that is my aim. 470 to 480 may be more realiztic. But if I aim for 480 I may only get 460 or 450.
    I need good head flow to produce it Good being a relative term. At least 200 cfm , probably 225 would be a good target. I need a cam that will make power at 7000 or just under that. I believe I have that taken care of. I need decent compression and I think I going to be good there. I need the manifold not to be a restriction at the very least. I intend to use a 750 Holley 3310. Headers will have to be right for sure.
    How will I know I guess is what you want to know.When I am done both the car and engine I will weigh the car and me or whoever the driver will be since it is possible I may have to slow down a bit. Then I will know from the MPH. I dont cheat either. With my current ride I am well aware I am not yet where I wish to be. I have used this method since about 1975 and have gotten quite used to it. Just sitting here from experience I know I will need a trap speed of above 147. Probably mid 150s but until I weigh the car I dont really know. However that is the plan. There is a section in my book on reading Drag Racing time slips. I personally am very comfortable with this method. Probably because for most of my life it is all that was available to me.
    The whole thing about dynos is pointless. I dont have reasonable access to one and I dont have the extra gold to spend on dyno time.
    Also the dyno didnt show anyone anything. Perhaps the man running it had a lot experience and showed a trick or two or suggestions that helped big or small. He could have just as easily done the same at the track and where would that have shown up? On the time slip in MPH. Please, fellows I dont have one I can't afford one and I am not going to do it so lets leave it there please. If you want to discuss dynos start a dyno thread. This one is not about dynos.
    Last edited: Aug 31, 2012
  24. magneto57
    Joined: Feb 20, 2012
    Posts: 125


    Wow thats cooooooool.........Rich
  25. Don"s writing for Chrysler Power again! :D
  26. Tis true. How did you know?
    Already finished my first piece. I am glad they are back.
  27. Cam grinder phoned yesterday. Had a couple of questions. Said they would be at it soon and he would call me when it is done.
  28. andrewk
    Joined: Aug 24, 2008
    Posts: 1


    Hi, been reading the HAMB for a few years now but first time i have contributed.
    I know its an old post ,but browsing through the other day i noticed a couple of pictures of an injected polyhead.
    I happen to have that injection set up.
    Purchased it about 25 years ago with the intention of one day using it on one of my poly engines.
    Well one day is getting closer.
  29. George
    Joined: Jan 1, 2005
    Posts: 7,593


    Good planning. Do an Intro before the Forum Police get ya!:)

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