Compression...and piston selection?

Discussion in 'Race 400/430/455' started by grant455gs, Jun 3, 2003.

  1. grant455gs

    grant455gs Well-Known Member

    For the second time now, my 455 has broke a hypereutectic piston. Why I fell for this trap a second time?? IDK:Dou:

    I made so many mistakes, its pityful, but I havn't had a whole lot of help either over the years. A whole lot of misinformation and HYPE from SO-CALLED EXPERTS! So if you don't REALLY know what your talkin' bout, PLEASE DO NOT ANSWER this post!

    I've known for quite some time that I REALLY NEEDED forged pistons, but stubborness and LOFunds jinxed me. Now I'm READY TO LISTEN!

    Anyways, I'm running 70 (wildcat) heads that have been "worked on" SEVERAL times! First time, valves were "converted to Stage 1", hardened exhaust seats, new guides and seals, new stock rockers. Cam was Poston 113w Rhoads lifters, all iron motor, breathing through straws! Gears were 3.90
    Second time, heads were "extensively ported" by a local "head porting guru" (my descrip.) Begrugingly admited airflow #'s at 276I & 199E?? Cam changed to TA 510H. Fed Mogul lifters were the only ones I could get to not collapse! Comp. was meas at 10.4 ACTUAL, 0-deck, 74cc comb cham. TA roller rockers, TA 17/8" headers, TA 3" dual ex. no crossover, TA SP1 (ported and matched by "local guru"), Holley 800D.P. (also worked over by same said person, increased to over "900 cfm"), 4.33 gears and 4.10's later, MSD ignition,and fuel system MUCH modified w/sump kit, Mallory Comp 140, -8 fuel line to reg. Trans. is a mod. T350, aftermarket bell, ATI 3800? (seems alot more like 4200 to me!!), and Hoosier 10"x 29" slicks.

    I've had a HUGE problem w/ rod bearings over the years, broke
    TWO HYPEREUTECTIC PISTONS! now, and had MAJOR problems with getting a "quality valve job", IE stem heights equal! This now seems to be addressed finally. I'm sure I've answered MOST of my piston problems, so let me be more presise:

    Assuming head and valvetrain stays the same, which piston/compression should I use? BTW rods were stock, but excessively lightened and polished, crank indexed, cut, polished, and everything balanced, TA S.F.I. flexplate, stock damper.

    This much I know, I will be purchasing aftermarket steel rods this time and aftermarket S.F.I. balancer, new forged pistons, and hopefully better machinework!

    I'm sure that this combo is a very hot street/strip combo but I've never really got shortblock assy to last very long??:Do No: :ball: :stmad: I have run a 12:20@110 60'@1.65 (4.33, BEFORE FUEL SYSTEM UPGRADE!!)

    I THINK THAT IT COULD HAVE BEEN/SHOULD BE A VERY LOW 11 SEC CAR!

    Any HELP? SUGGESTIONS? COMMENTS? PISTON/COMPRESSION???
    :confused: :confused:
     
  2. rh455

    rh455 Well-Known Member

    Grant

    I've never been a fan of Hyper's, but I do believe that there are some engine builders here that DO know how to set up/use them. I've always felt that forged are the only way to go. The combo that you've listed reflects 11 second capability just set up issues, cam selection and verifying head/intake flow. The piston that really appeals to me are the TA conical dish and the Wiseco 10.0:1. Both really look nice and I've seen some really impressive et's with both. It would be money well spent on either.
     
  3. Jim Weise

    Jim Weise EFI/DIS 482

    Grant,

    From what a recall, I believe I heard that those pistons have a 16 cc dish. If my memory serves, since I have only heard the CC of the piston, and have and will not use that piston, I could be wrong.

    If that's the deal, then assuming .040 composition head gaskets, your compression is about 10.5-1, which is a little light for that cam, in my opinion. I'd like to see you run another full point, if your going to hang onto that cam. Or, your going to have to advance the cam 6-8*, to get the intake valve closing number in line, so the motor will make decent mid range torque. But it's a better deal to run it with the higher compression, and run the cam 2-4* advanced.

    As far the rotating assembly goes, do yourself a favor, and get the sportman rods, and SRP pistons from TA... super nice pieces, and once you buy them once, your good to go.

    Your also looking to put that motor in block girdle territory, so get on of those on there.

    Run a TA cover, or a good stocker properly set up and ported, run an aftermarket or stock deepened pan, and you should be good to go.

    Personally, I would get the girdle, rods, pistons, chuck that hydraulic cam, put in a TA 298-04F solid cam, run the compression up to around 11-11.5 by cutting the decks on the heads (you will need64- 60 cc chambers) and go for it.



    Got a motor just like that on the stand now, except with 316/236 cfm STG 1 Alum heads, and a matching solid camshaft for that combo, and I fully expect it to make right around 600+ HP. You should be able to do about the same, with your iron heads, and that bigger cam.

    It's our new Level 2A-HP motor, and should be on the dyno next week.

    That will get you way down in the 11's, if not into the high tens.
     
  4. grant455gs

    grant455gs Well-Known Member

    I'm thinking that 10.4 (if that was actually computed right), is REALLY much too low.. cranking compression was VERY LOW, around 140-160 if I remember correctly. It was a few years ago:Do No: . I don't remember if I played around with cam advance or not, I think I advanced 4 deg. w/rollmaster. If I'm supposed to have 200-210psi, would I be correct in assuming that 1) Cam too large for compression 2) Could have advanced the cam more (TA advised 8 deg advance!) 3) If I want to stay with this cam, I need more compression.

    More Questions::Dou:

    1) Assuming .030+ bore, 74cc comb. chamber, orange crush gasket, 0 decked block, what would comp. be with Wiseco/flattops Vs Wiseco/flattops?

    2) Assuming my headflow is right ( I think it was 266 Intake not 276! 199 exhaust is right) am I on the right track with compression, headflow, cam timing?

    3) I really want to use a solid lifter cam , but think that TA's 308S is MUCH too large for my combo (maybe alum. heads w/porting!). Would TA 210 work alright?

    I hope someone will help me, and I'm not :boring: you to :sleep:

    I also realize this is a busy time of year for most of us, so I appreciate your help/advice!:beer
     
  5. grant455gs

    grant455gs Well-Known Member

    Thanks Jim for responding!
    So you think I should use dished pistons, (TA/SRP's are a fine choice, OK with me!!), and mill the heads down to 60-65cc's??

    I really do want the solid cam, but what is this new T/A one? I've never heard of it?? Are the specs listed in their catalog?

    Actually, I'm trying to stay less than 600 horses because 1)weight of car,3600lbs; 2) Strength of rearend, mildly builtup 12-bolt; and finally trying to avoid girdle! Should I just deal with the first two, and finally accept the girdle?

    I have a homebuilt deep-sump oil pan that strangely resembles T/A's in every way, but I'm thinking about Poston's alum one w/girdle. I know there NOT as good, but what are your feelings in MY case? Not good enough? OR probably would work? How does T/A's girdle work with steel oil pan?

    How much are those new blocks??

    My wife is standing right behind me :spank: Ouch! quit hittin me!!
     
  6. GS Kubisch

    GS Kubisch THE "CUT-UP" BUICK

    Grant
    Don't be too afraid of the 308s....
    A few years back while waiting for a motor I used one in a basically stock 69 430 shortblock.
    800 Holley
    TA intake
    "Not as good" (as yours) heads
    compression was 9.6
    4.10 gear w/30" tires
    4200 stall
    3500 lbs w/driver
    I ran 11.26 at 116 w/ a 1.47 60 foot

    for what it's worth....also w/ the 308S

    When my 464 was ready w/ better heads and more compression I went in the 10-teens after getting the race weight w/ driver down to 3200lbs.

    There are a few good forged pistons out there.
    I would get away from the "Hypers" as quickly as possible.

    Don't rule out grinding the crank to use a Chevy rod.
    In some cases this is more cost effective/practical.

    And if you don't/can't go with the girdle,I know of some that have gotten away with "pinning" the main caps.

    The new iron blocks are in the $3700 range....

    Good luck,it sounds as though the car should be well into the 11's even at 3600 lbs.

    Tell the Wife.....At least she can find you.You aren't the fool spending all the cash at the Bar:Smarty:
     
  7. grant455gs

    grant455gs Well-Known Member

    Umm, I WAS the guy at the bar for the last 5 years...:Dou: Cars been sittin' for awhile :Dou:
    I'm in AA and treatment now..there's HOPE:grin:

    I havn't ruled out BBC rods at all, as a matter of fact I wonder about their possibility 10 years ago:Brow:

    Is there a FACs here on how to use them exactly?:confused:
     
  8. grant455gs

    grant455gs Well-Known Member

    This is where I thought I should have been last time I ran,:Do No:

    Maybe it had to do with stock fuel line and Stage 1 mech. fuel pump?:error: :jd: :Dou: :spank:

    That's been taken care of now with rear sump kit, Mallory Comp 140 pump, and various sizes of braided fuel line:TU:
     
  9. rh455

    rh455 Well-Known Member

    Jim

    Isn't that a lot to cut from those heads? Won't he have to get the intake milled to match? That cam must be something new and not in the catalog. It looks like something just below the 308s. Can 11.0:1 pistons still run on pump gas if zero decked?
     
  10. grant455gs

    grant455gs Well-Known Member

  11. grant455gs

    grant455gs Well-Known Member

  12. grant455gs

    grant455gs Well-Known Member

  13. Jim Weise

    Jim Weise EFI/DIS 482

    I would really be surprised if that Rod is not made by Crower.. Looks exactly like the the TA Sportsman Rod, which is made by Crower for TA exclusively.

    IT's a real good rod, and yes, you can use Chev's, or Pontiac rods, and fool with the bearings, but once again, not worth the hassle if you ask me. Once you own those rods, they will go in any Buick motor, on any crank, and work with any Buick Piston.

    Yes, that 04F cam is a new one, and it's a bit smaller than the 308, but like was mentioned, I would not be afraid to go with the 308 either.

    You could go with a flat top, as long as you don't mind the 12.25-1 compression, and if you went with a 308, I would prolly want that compression. Like Gary, many years ago, we ran a full weight (4100 lbs) GS, with 240 cfm heads, SP-1, TQ-1000, and the rest of the race car goodies, and that car went all the way down into the 11 teens at 120 mph.

    Would have been easy high tens, with your heads.

    As far as dished pistons go, if you build and 11-1 motor, cut .040 off your heads, you could possibly get away with just putting around on the street on pump gas.. but when your into it, your going to want to have prolly a 50/50 mix of 108 and pump premo. But of course, this varies with each motor, and you need to be careful about not detonating it too much.

    I personally like that SRP piston, because, aside from all the other features it has, it has a conical dish.. so the piston is balanced unto itself, when you consider it's weight on each side of the pin axis. Inverted Dome pistons are generally out of balance, and their is varing opinons on out there as to the effect of this out of balance condition.

    I have personally seen 3 STG 2 pump gas motors over 600 HP with these conical dish pistons, in the last 3 months. So they certainly seem to be working well.

    buck up an buy the girdle.. trust me on this one.. yes, $1100 now, by the time you put it on, but it's an investment, and an insurance policy.

    And think where you would be at money wise, if you had only built this thing once! Make sure this is the last time....

    just food for thought.

    JW
     
  14. Jim Weise

    Jim Weise EFI/DIS 482

    Dude.. the block girdle is still $495.... but it does not just fall onto the motor... it takes $5-600 worth of machining to put it on, if they do it right with a surface of the oil pan rail, and then do the line bore to the mains.. bore, not hone.. I have all my motors bored, with a girdle, because the sizes come out more accurately, thruout the block.

    Same price as it was in '95, more or less..


    Sportsman rods are $699... and IMHO worth every bit of the price difference over the cheaper rods.

    SRP Pistons, if he is still running the intro price, are $585.00

    Very nice pieces for the price.



    JW
     
  15. grant455gs

    grant455gs Well-Known Member

    True, true, your right on the girdle, and I TOTALLY AGREE with prices for machine work needed! I see what you meant now. I just ASSumed they had gone UP!

    The Sportsman rods, again I was wrong I thought you were talking about the "GOOD ONES". I didn't even know they offered a $699 for us "medium" guys:Dou:

    The SRP's also definetely fall into my price range. Prolly the best choice for my combo too!? JE's prolly arn't best for ANY street use!
    What's wrong with the Wiseco's? (Two Jim's are confusing!)

    I truly appreciate the time you have spent:Comp: today, and I DO agree with EVERYTHING you've recommended. I just want to make sure in my own mind that I'm getting unbiased and unopinionated advice THIS TIME! It's gotta be RIGHT THIS TIME!! :stmad: Anyways, thanks for the
    advice, :grin: you've got me pointed in the right direction!! :TU:
     
    Last edited: Jun 4, 2003
  16. grant455gs

    grant455gs Well-Known Member

    :Dou: Yeah anyways I'm done beating myself up over the past, time to move this baby forward...

    I'm full, THANX!:grin:
     
  17. Jim Weise

    Jim Weise EFI/DIS 482

    Posted previously..I personally like that SRP piston, because, aside from all the other features it has, it has a conical dish.. so the piston is balanced unto itself, when you consider it's weight on each side of the pin axis. Inverted Dome pistons are generally out of balance, and their is varing opinons on out there as to the effect of this out of balance condition.

    Wiseco's have an inverted dome..



    Two different points of view..

    JW
     
  18. Bobb Makley

    Bobb Makley Well-Known Member

    Pistons

    I decide to do some investigating after reading Jims post on pistons. I figured if the conical dish was the better piston then we were going to have to have Wiseco change the design. I thought I would share my findings with all of you:

    This info is from Wiseco pistons and is their reason for doing the pistons in the manner they do

    The Wiseco is a mirrored reverse dome, which means the underside of the piston has the dome on both sides, which negates any issue with balance the only issue that is there will be from valve reliefs, which will be virtually negligible.

    A reverse dome piston offers a better Quench area than does a Conical dish piston.

    Do to the design of the piston it can be produced lighter than a conical dish for a lighter over all weight. The conical dish piston has to start with a thicker top to allow for machining

    Once again do to the design of the piston and the amount of material that has to be machined from the center of a conical dish piston a reverse dome has a stronger deck surface (NO2 :Brow: )

    This leads me to believe that a lighter piston that is stronger and has no balance issue is not such a bad thing.

    I was told that a conical dish piston is far better for a 4 valve head than a reverse dome though:Dou:

    For just a kicker he also told me that there are far more reverse dome pistons used in NASCAR than the conical dish.

    I just wonder if piston companies are going to conical dishes do to decreased machining cost or better performance :Do No:

    Before a flame starts I posted this for a, from the other side of the fence kind of thing only. It appeared to me that the Wiseco was becoming a target and I decided to try and offer up facts for its design not assumptions. I hope this may help anyone looking at pistons there are several sources for Wiseco. PAE, Dehabey Racing and Finish Line Motorsports.


    I will post my opinion on the rod issue also the TA Rod is a very nice piece. As for a drop into the engine and go extremely good value for the Quality and the money. That being said I have not built a stock stroke performance motor for anyone for a while. Up until recently we have not had a good bearing to put into one and bearing speeds are always a concern. I can sell a set of 6.800 long eagle rods for 400 bucks that give you a better rod to stroke ratio than we already have and decrease bearing speeds at the same time. To have a standard crank ground it will cost 100 to 150 dollars depending on the grinder and to have a stoker cut to except stock width BB Chevy bearings cost around 350 to 375 a difference of around 250 bucks add that to the rods and you have 650$ plus better rod to stroke ratio, lower bearing speeds and you can get bearings anywhere you wish to buy them. The big thing is you can tell your buddy's you have a 470:TU: . I just like the value for the dollars spent better than doing a 464 but that is strictly my opinion and like a you know what, every has one.:moonu: I meant a Chevy by the way:laugh: :laugh:
     
  19. Jim Weise

    Jim Weise EFI/DIS 482

    Good info Bobb..


    I had wondered if those Wisco's were a mirrored deal..

    Other features that piston has?

    Lots of ways to skin the cat.. so to speak..

    JW
     
  20. Bobb Makley

    Bobb Makley Well-Known Member

    features

    Jim

    I went back and found the post that we were comparing pistons from earlier this year. just thought I would repost it here.


    Sorry guy's I had to go staight to the race shop tonight so I could not answer your Questions before this. I would like to say these pistons are designed to fill a gap between speed-pro pistons and High dollar lightweight ones. So I will do my best to answer all the things you have asked if I miss something just let me know and If I don't have the answer I will try and get it.

    I will do the flat tops first

    Weight 679 Grams
    Compression height 1.98
    Wrist pin 1.00
    Deck thickness .180
    Valve reliefs .260
    Pocket dia. 2.45
    Pin oilers Yes
    Radius valve reliefs
    Pins are fit and do have locks

    Now for the dished pistons

    Weight 700 grams
    Compression height 1.98
    Wrist pin 1.00
    Deck thickness .325
    Dish .125
    Valve reliefs .260
    Total of -22cc
    Valve pocket dia 2.45
    Pin oilers yes
    Radius valve reliefs
    Pins fit and do have locks


    As far as your question about custom skirt designs It does have the same skirt as my race pistons based on the number given, But I do not pretend to know anything about designing a piston so I let them do it.

    Over size are .038 and .060 we do not have .060 it would have to be ordered in

    Piston rings are Hastings Power-Flex moly race rings. They have the vent flex oil control ring, which is one of the best designs in the industry. We use these rings in all of the motors we build from our tube car up to my wifes regal. Wisco provides these with the pistons we have not added these to the deal ourselves.

    The radius valve relief is what gives the illusion of it being deeper Jim instead of a straight edge they have put a small radius in the relief to enhance flame travel.

    I hope I have answered all the questions if not just ask or give us a call and we will try to answer them.

    As you stated about the ta piston these are the same as the srp they just don't have the internal lightening done to them as there race version does.
     

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