81 Trans Am 500 Caddy

Discussion in 'Big Block Cadillacs' started by PJ McCoy, Jul 23, 2015.

  1. PJ McCoy

    PJ McCoy Well-Known Member

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    Hello everyone, I'm PJ and new to the forum. A big thank you for this web site. I've been reading for awhile. Learning allot. I figured how to shoe horn that BIG motor in the Pontiac cross member. :cursing: , Ill be posting pics as I go. The car was road ready, everything was fine, Then i got to reading about cams, carbs, timing, more fun more power ect. So i took the car apart again, 3rd time. :banghead: So I've got a new cam, never installed one! A Quadrajet rebuild kit, new lifters, LS7 valve springs, Cloyes timing chain, had the heads machined to fit the springs, new comp keepers. new push rods .030" longer., just wanting to make the top end a little stronger. Thanks Dave Brode. Followed allot of his comments. Lined up with my research. Headman headers with a Caddy flange. 2.5 inch dual exhaust. ARP connecting rod bolts. Everything else is stock. I've hogged out the stock intake, the 2115 intake will hit the hood so its out of the question. I've got lots of pics on that. It might help others in the future. I'll have to work on the distributor, Which I know nothing about, (have read allot but never done any work on it). I'm going to try to smooth the heads out a little, It looks like there is a lot of meat in there that will help when removed.
    I've got a MSD ignition, the rev was set at 4600. I am not trying to win races. Just smash the gas and smile very big.



    https://www.youtube.com/watch?v=ySHt9P5jyPs

    Please let me know what you think, the car has a 3.08 rear. not sure how that will effect the car when I am done.
     

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  2. PROSTOCKTOM

    PROSTOCKTOM Well-Known Member

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    Re: 81Trans AM 500Caddy

    I owned a 1973 Trans Am with a 455 in it. I can not imagine what a 500 Cadillac would be like in one.

    Looks like you'll have a fast car going there. :devil:

    Tom
     
  3. The Mad Cadder

    The Mad Cadder Well-Known Member

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    I see Lunati on that box.. Affraid to ask
    What grind is it ??
     
  4. Darius

    Darius Well-Known Member

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    Mad, you say the "grinds" done by Lunati for Caddy engines are poor choices for us as those profiles were designed for and are better suited to Chevrolet engines; -- and I'll totally trust you on that.

    My question is: why do we see new to the Cadillac Power Forum members choosing Lunati? Are they the low price leader? Are they being pushed by Summit, Jegs ect.? (I understand you'll have zero idea why anyone does anything but you might know the price structure of the various cam vendors and their wares.)

    Best, (PJ, I don't mean to hi-jack your thread.)

    d
     
  5. The Mad Cadder

    The Mad Cadder Well-Known Member

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    I don't know.. Big name easy to find etc..

    One thing for sure as we have seen many times before he is no doubt headed for certain disappointment with it

    Keep in mind Marty uses them for a cam source why in the hell they don't aleast offer some cams that mimic the kind
    that work is beyond me... But good for Uncle M

    If it is the kind of grind I suspect and if he hasn't run it I would try to get my money back
     
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  6. PJ McCoy

    PJ McCoy Well-Known Member

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    Re: 81Trans AM 500Caddy

    Thanks well see. Im not sure what im doing. reading and following advice. The car was fast in stock. Just not fast enough :bolt:
     
  7. PJ McCoy

    PJ McCoy Well-Known Member

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    Darius your not hijacking, i like the feed back. Thanks. Mad Cadder, My daughter used the tube from Herbert Cams for a project. I got the L,box from a friend, The cam card reads:
    intake .487@1.65
    exhaust .520@1.65
    cam timing
    ivo 24.5
    ivc 60.5

    evo 73.5
    evc 21.5

    108 IC
    112 LS
    Question # 1 Why are stall converters used? #2 would it be wise to run one on a street strip application? Not sure what stall to get if needed?
    So the story goes like this, My dad back in hay day thought Herbert Cams was the deal. So i got a good mid range cam. Thats what dad thinks. I wanted him to be apart of this build for memories. Hope the cam isnt a cork screw POS. I wanted the mts #10, but went with my pop. Please let me know what you think! Be honest i dont want to do it again. It needs to be done right. thanks guys. Btw Im porting the stock bowls, nothing big just smoothing everything out. Man the bowls need some work dont they?
     
  8. Natonia1969

    Natonia1969 Active Member

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    My mt10 and 20 came in a lunati box. Anyway welcome to the forum man. Good luck with your build. I'm not as technical as some of these guys but I can definitely help if you need it by I just finished my build so all the issues are fresh in my head still. :irked: you're smart by keeping your build close to stock. It will be a beast trust me. :thumbup:
     
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  9. pila78

    pila78 Well-Known Member

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    Are you using the stock rocker arm set up ?..just wonderin' :D
     
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  10. PJ McCoy

    PJ McCoy Well-Known Member

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    Here are some more pics. Then ill tell you ya a story, Its true.



    So When i had the stock motor, I could not get the car to hook up.
    She just spun her tail off. I loaded 8 20lb bags of sand bolted a set of mud truck tires, She bit hard, So hard the driver front fully extended, i dont believe it came off the ground, next thing i know. the car leaps forward, pinned to the set, My girl is in the back set behind me, My son sitting next to me. The seat bracket bends at the rear. My head is in Caysie's lap. :eyepopping: Knees suck under the steering wheel and dash, Tyler had to grab the wheel to keep us from crashing into the ditch. I forgot to put bolts in the front of the seat. :screwy: The windshield cracked at the lower right and popped out far enough to put my hand in and touch the dash.
    Thats when i realizied I LOVE CADDY ENGINES. Never in my life have i felt such power. Crazy story but true. Just wanted to run the car and forgot about the bolts. I should not have dropped her in gear at 3500 either. :shakehead:
     

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  11. PJ McCoy

    PJ McCoy Well-Known Member

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    Yes, rockers are stock. Im not going to take the car past 4500. I believe the MSD is set at 4300. I will have to double check in the morning.
     
  12. PJ McCoy

    PJ McCoy Well-Known Member

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    Thanks for the support. When i called Marty about the direction i should go, He said," Just remember lots of horses eats lots of oats." Man that stuck like glue. Im glad to be part of the family. Thanks again. Ill be ordering some push rods from him soon. What do you think about the cam size to small, big what?
    PJ
     
  13. Member 3508

    Member 3508 Active Member

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    Ditto on the keeping it stock, it makes it cheaper too.

    On torque converter with stall rating, they have to do with optimized power delivery. If you had a trans brake that holds first and reverse locked together in the transmission, it allows you to rev the engine without moving the car. If you had a 2500 stall, your converter will slip and your engine with rev to 2500. A 3000 would rev to 3000, a 3500 will rev to 3500 and so on. This doesn't work with foot braking.

    Why do you want this? Well different engines make power at different RPM ranges. You want to try to match the converter to your cam characteristics. So if you have an aggressive cam that has a power band of 2800 to 6500 RPM, by selecting a 2800 RPM stall you will launch the car within the power band. If you only had a 1800 stall however, the car will be a dog off the line because the converter only slips enough to let the engine rev to 1000 below the start of the power band before the car starts to move. If you select a 3500 stall you will blow the tires off because you've now shot way past the start of the power band and you are in the midrange now, which is too much for Street tires usually off the line.

    Now I've over simplified this to make it easy to understand, but it's not quite that simple. You have to consider the flash rating also which is more applicable to street, weight of car, stator angle for tightness, etc... Stuff that I'm not an expert on. Bottom line is you need to match the converter to your cam and your engine in general.

    Hope that helps. The guys here can help you pick a good one but only after you select a cam.


    My personal opinion about cam is get the MTS #15. It's the best all around cam. Street able but wild when you want it to be. Very well mannered all around.
     
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  14. PJ McCoy

    PJ McCoy Well-Known Member

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    Hello Mad, Its not a lutini, its just an box to put the cam in. Herbert made the cam. Ive posted the specs in this tread. I would realy like your feedback about this grind. If its something that is not going to work well. i will sell it on ebay! Ive had it for about 5 months and my daughter used the tube that it came with. Thanks PJ
     
  15. PJ McCoy

    PJ McCoy Well-Known Member

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    Thanks for your help, that is exactly what i was thinking but not sure and i didnt want to look like fool. Ive selected a cam, I think ill just buy a new converter, all stock, and stay happy. thanks again PJ
     
  16. The Mad Cadder

    The Mad Cadder Well-Known Member

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    Does the cam card list .05 events ??
    I realize its lists lifts with 1.65 rockers but does it give lobe lift ??
    Listed lifts with rockers are occasionally wrong

    Based on what you listed I get 265 and 275 gross durations.. really small
    Cadillac's specially with early heads do not need a longer exhaust event.. Certainly not 10 degrees..

    If your going to use stock rockers with anything over 200 open pressure you need trash screens to catch your lifters and pushrods !! :yikes: ..I broke a bunch trust me :yes:
    And keep a close eye on the oil pressure gauge [ not a bad idea anyway ] Only done this as a kid wouldn't consider doing it now not worth it

    And like Franken said the MT15 is your best all around stock head port/valve cam for power.. Since you already have it keep the converter..
    Keep the trans fluid cool it makes for less slippy
    you'll be amazed


    Along with the bowl work you could also straighten the pushrod wall BUMP a bit ... Since you are using stock valves don't move it just square it up
    Narrow and tapper the guide bosses as well

    Oh and the stock rods are good for 5500 easy.. If the new bolts require machining the rods to fit DONT use em
    The rods thinnest point is already along and behind the bolt head area
     
  17. PJ McCoy

    PJ McCoy Well-Known Member

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    Thanks Mad, Now im concerned about the open valve pressure. I have no clue how to figure this out. Also dont have the .050 # you are asking for. Ill have to go to the web site and see if i can find it. Thinking i might be better off getting the #10 or 15 cam and selling the other on ebay. That will put my build back alittle. I do not want to put a rocker shaft in. im going to keep the rpm low i think :scratchchin:
    Ill look up Herbert Cams and see if can find it or give them a call. Thanks again
     
  18. PJ McCoy

    PJ McCoy Well-Known Member

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    Found it on the web site.
    Product Description
    RPM Range: 1000-5000

    Advertised Duration: 265/275

    Duration @ .050: 215/230

    Lift: .470/.505

    Lobe Center: 112c



    Cadillac V8 68-84 368-425-472-500

    BB Cadillac Hydraulic Flat Tappet Cam & Lifters- Great torque, upper bottom end and mid-range power. Nice idle. These cams are designed for use with stock retainer/locks. Check clearances.

    Chet Herbert Cams has been grinding cams since 1949. Performance, high quality and a low price. Everything you want in a performance cam and more. Cams for your tow rig, street performance, street-strip or race. If you need assistance picking out a cam please call our tech line at (704)732-2400.

    Tech Tip: When checking for valve spring coil bind, also check for retainer to valve guide clearance. There should be a minimum of .150? clearance between the guide (or valve seal if used) and the retainer.

    Tech Tip: Flat tappet cams (hyd. or solid lifter) require to be broken in for the first 30 minutes of operation at 2000 rpm. During this time do not let the engine idle. If adjustments are required during this break-in period, you must shut the engine down completely. If using a spring with over 130 lbs. seat (or over 330 open), you should remove the inner spring during break-in.
     
  19. The Mad Cadder

    The Mad Cadder Well-Known Member

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    Sorry .. I understand your connection of the cam to your Dad.. My Dad is the reason Iam The Mad Cadder.
    Try to think of it as your Dad just wanting the Caddy to make more power it might make the choice easier

    That's typical of the big name cam grinds... Not enough lift for duration and wayyy to much exhaust bias
    The .05 intake duration is about what the good stock cam had

    A MT15 will walk all over that

    I don't think you have said which heads you are using if they are 76cc versions
    The best cam I had in a stock kind of build was 236@.05 113 lsa .320 lobe ..I had 1.72 rockers so it had .550 lift.. And that was a 472
    Marty will sell you a custom grind for the same price as off the shelve and it takes only a couple days longer.. Then you could have it
    done on a 108 :gnasher: It would thump and kick ass

    The seal only needs limited clearnance.. Even .02 is good really as long as it clears its good
    You need atleast .06 from coil bind

    Just sayin .. I have never removed the inner spring and have never had a failure in over 30 installs

    Expect stock rockers are going to break at 330

    You might try to explain to them that their cam is obviously not a tested grind and you want a decent grind in its place.. never know


    BTW
    Rpm has little to do with the stock rockers surviving.. I had one break at idle..
    If you get 8 good tee's they may last but it really aint worth it
     
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  20. PJ McCoy

    PJ McCoy Well-Known Member

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    Mad Cadder,thanks for the feed back,the block is a 1976. So i believe they are the 120 heads. Yeah the purchase of the cam was an emotional one for sure :cloud9: me and dad, But reality seems to bite me every time! So this cam is really just like stock? should just keep the one i got in there. If i were to go with the mts 15 i would have to change alot in engine correct? I know the MTS10 will work with stock rockers,Just not sure how long they will last.. It seems like my budget is going to be blown very soon. Btw, I could be entered in a CSOB contest. lol I dont want to build this again, putting in a cam im not happy with. this is exactly what Marty was telling me, Know what you want before you buy, Plan your build and ask lots of questions, Over the phone conversation. I thought i was making the right choice.
    If i get the rocker shaft assembly, that would give me more lift correct? would that help the little cam? Just brain storming to try to make this work if possible. #15+new lifters+shaft rockers 299.95+595.95=895.90 not counting the push rods.
    #15
    RPM bands on this camshaft can exceed the boundary of safety for engines with stock connecting rods. Forged “H” or "I" beam connecting rods are preferred. If you want durability, aftermarket rocker assemblies are also required at this level of power and ported heads are strongly recommended to facilitate the build. MTS site.
    Boy how i wish i didnt buy it at all. very discouraging. I still have allot to do to the car, Front break lines, rebuild the carb, dizzy and trans. Ive got the rebuild kit for the trans, and the carb. Saw a post from Dave B. with the site for the rebuild kit for the carb, so i ordered it. and i havent finished the head work. Allot to be done, i have time to save some Money up.
    Any input from the other guys would also be helpful.
     
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