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lets talk roller cams and a tbi question to go with it.

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Seventy4Blazer, Mar 5, 2003.

  1. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    ok, im looking for a roller cam with a profile as follows....
    duration at .050" intake 204* exhaust 214* lift, int .420 exhaust .442 DOES ANYBODY MAKE ONE? or am i going to have to go to the next one up or a custom grind?
    i also will be running a 1.6 rocker arm. roller rocker of course. might as well do it all.
    this is the same profile as the edelbrock performer plus. would it be to much for a stock tbi? or is there another reason, knock sensor, for a smaller cam on a tbi?
     
  2. tmaxxer9

    tmaxxer9 1/2 ton status

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    well i'd love to, but i don't even know what they are.
     
  3. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    ok, i found a cam. the part number was right in front of me all the time.
    crane makes one. part number crn-119811
    check it out at summit if you want to learn.
    grant
     
  4. RustBuket

    RustBuket 1/2 ton status

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    I don't know much about your other questions but you can usually find good rockers on ebay for like half the price.
     
  5. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    yeah, im not worried about rckers right now. i just need to get a cam in so i can get the motor and drive train back in the truck. but i dont want to get a cam that will play with the TBI stuff.
    grant
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    http://www.cranecams.com/master/apps/chevy18.htm#2.%20PowerMax "HR-260-2-12 IG" is the one you are talking about, no?

    What are your intentions for this motor? If I got the cam right, this is the exact one I am going to be running, and it's retrofit. If it is, my advice...don't waste your money! I won't go into detail unless you want to hear it, but I have that cam and matching lifters sitting in my garage to go into my 1969 350 block, and I can tell you, the cost isn't worth it. I made up my mind a long time ago (before lifter prices went up $100/set) so i kind of forced myself into them, but if I could do it over again, no way.
     
  7. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    yes, that is the one. details please. it is a lot of cash.
    maybe you would be willint to sell yours? like i said before i would be going with a 1.6 roller rocker as well on 7/16ths studs.
    i want torque at the low end, but i will be running 2m465/203(eventual doubler) and 4.10 gears with 42 inch trail tires and 37 inch street tires.

    aluminum intake, prolly a performer or very similar to one.
    and then a TBI setup.

    thanks for the help,
    Grant
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    Sure, details:

    The cam is pricey at $300 (as I recall at Summit). Besides, Crane had to grind it (they don't keep them on the shelves) and it was 1-2 weeks wait time. (shop didn't call me right when they got it)

    The lifters are pricey, and from what I was told, the "standard" retrofit roller lifters won't cut it in an every day driver, you need the "X" lifters (885X or similar number in *comp cams* catalog) to hold up. Stock roller lifters have NO reliability issues, to pay $500 (yes, thats how much they cost) for retrofit lifters that will "hold up" is garbage. The link bars are the weak point, and I'm sure thats why the factory doesn't use that style.

    My main gripes are obviously cost and reliability. Honestly, knowing what I know now, I would not hesitate for a SECOND getting rid of my older 350 block (if it wasn't already worked on, along with having ordered the roller retrofit stuff) and buying a short or long block 1996 4 bolt main one piece rear main roller lifter engine.

    The lifters last, the cams and replacement lifters are cheaper, the one piece seal is better, and the roller lifter retention/alignment method is better.

    You can get 1996 long blocks for around $1500 (with core charge included I think), which, once you factor in the qualities it has, along with all the machine work and retrofit stuff, is not that more expensive. You are looking at $800 JUST for retrofit roller parts, plus new springs, roller cam button, and so on. Add another $600 for the machining of an old block, pistons, rod resize, etc., and you are already there.

    I didn't know about the newer blocks before, and I'm paying for it now. If this motor comes apart after 5 minutes of run time, I'm going to go right out and get the long block 1996 motor and never look at the retrofit stuff again. Of course there will be other issues (new flywheel, can you get the cam you want put in it, etc) but I still think the pro's far outweigh the cons. There is nothing worse than worrying about engine components/reliability every time you drive a vehicle.
     
  9. XHitman396

    XHitman396 1/2 ton status

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    ok, maybe im retarded, but u said lots of stuff i didnt know what was goin on, are u sayin its not worth it to put a cam in an 87 tbi?? or just the rockers are the problem? u have to have roller rockers? or special ones? sorry for the lack of understandin, but was gonna put a cam in along with exhaust and intake manifold, thanks...
     
  10. 4DiggerDan

    4DiggerDan 1/2 ton status

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    For once I'll completely agree with Dyeager... If you're going roller, buy a late one piece rear main block. In all the TBI's I've seen, they started putting the roller blocks in trucks as early as 89. Even though they didn't go roller on them until 92 (I think...) They used the same block for the Camaros (which some had roller sticks) and I think some of the Vette's too, until the LT1. There's even roller cam blocks that you can run a plain old mechanical fuel pump on out there. They're real easy to spot in junk yards too, if it has a block off plate bolted to the block where a mechanical pump would be, then its drilled for the fuel pump eccentric These are the best blocks to keep around your shop, because then you've got options... You can make a roller cam carbed engine (which we do quite a bit.) Most of the late roller cam blocks are two bolt main. Its very rare to encounter one thats a 4 bolt. However in my opinion, either set up is equally strong. I've abused both types enough to know. You see 4 bolts tear a main right out of the webbing, and you see two bolts break caps... Unless you go splayed 4 bolt main (where the two outside bolts are tilted outwards.) you're best bet is staying around 450 horse and 425 Ft/Lbs.

    I'd be taking a look at like the Comp 08-409-8 for a torquey 350... It runs a little wider LSA (lobe seperation angle) than the other "Extreme" roller cams. Thats one of their "Extreme 4x4" cams. All of the Extreme 4x4's have like a 112 degree LSA. That means it'll make more torque and vacuum (which is what a MAP sensor needs to work) and less ponies. If you score a used long block that is machined for roller cam, but doesn't have one, don't sweat it. Go to the pick and part and look in the wrecked S10 isle. Find early to mid 90's 4.3's (the ones with timing covers that look like early 350's) and rob the lifters, links and a thrust plate out of two trucks. Then you have 8 extra lifters and 4 extra links. 4.3 Chevy's are basically a 350 missing the front two holes (I always wanted to get and even fire pattern billet crank ground to 3.750" stroke and build a 292 V6 stroker, but thats a different subject....)
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

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    I didn't keep tabs on the exact time frame, but the blocks are the same between cars/trucks, just that apparently most or all non-roller truck motors of that time don't have the bosses for the lifter "spider" (what keeps tension on the pieces that retain/locate the lifters) tapped. It's an easy fix from what I've been told.

    Check ebay out for stock roller lifters and or cams from a Camaro. Cheap. Don't even have to spend time pulling them if you don't want at those prices. A long block should have lifters anyway as I understand it.

    As to the other poster, no, you don't need different rockers (although I went full roller on them) but the new springs are typically required due to the roller cam. If you are going with a hydraulic flat tappet cam, you don't really need to worry about any of this stuff (given that the cam isn't too much for whatever springs are on it) as the hydraulic flat tappets are what are stock in these trucks.

    You can check out these guys http://www.chevy-350-engines.com/ to see the 4 bolts, but as you said, I think the strength difference is minimal. It's kind of curious though, with the strength difference being minimal (if existant at all) why did GM "waste" the money on them in the "heavy duty" applications? I could see it if it was a marketing ploy, but AFAIK, it was never advertised which vehicles had 4 bolt blocks.
     
  12. 4DiggerDan

    4DiggerDan 1/2 ton status

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    I really don't know why GM went 4 bolt on their mains in "heavy duty" stuff. Thats a great question though... I always wondered shy they didn't do like Ford did on the Windsor and go with a HUGE main diameter. Think about it for a second... When was the last time you saw a 351 Windsor break a main, or break a crank THROUGH a main. All the Windsors I've ever seen were two bolt main.

    Another thing about roller lifters. The biggest thing to pay attention too is diameter of the roller. A smaller roller will give a little more agressive opening and closing rate than a bigger one will. This is easy for 4 wheelers to understand /forums/images/graemlins/rotfl.gif There's not a huge variation in Chevy's between OEM and aftermarket. Not like you see with other manufacturers...
     
  13. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    i was at my second job today and looked at a long block sitting on the ground that was pulled from a burban. im not sure what year, but it was LATE 80's maybe a 90-91. in the lifter valey it had bolt holes that were elevated about
    1.5 inches or so. also had center bolt cyl. heads and 1 piece rear main. the fuel pump area had the cover. i didnt have time to get a number off it, but is this what i am looking for?
    grant
     
  14. dyeager535

    dyeager535 1 ton status Premium Member

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    I *believe* so. I bet diggerdan has a better idea. I've been unfortunate enough to have never seen the lifter valley of a roller or roller-era SBC.

    AFAIK there would be no other reason for the "bosses" in the lifter valley, but I'm not positive how many the roller block would have. My thought is that there would be 3. Check out ebay for roller lifter SBC parts, see if someone is selling one of those setups complete with the "spider" hold down.

    Wrong make, but heres an idea of what the "spider" looks like, along with the pieces that keep the lifters from rotating. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2406525081&category=33614
     
  15. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    i looked at a long block sitting on the ground that was pulled from a burban. im not sure what year, but it was LATE 80's maybe a 90-91. in the lifter valey it had bolt holes that were elevated about
    1.5 inches or so. also had center bolt cyl. heads and 1 piece rear main. the fuel pump area had the cover. i didnt have time to get a number off it, but is this what i am looking for?

    you got any input 4diggerdan?
    thanks.
    grant
     
  16. 4DiggerDan

    4DiggerDan 1/2 ton status

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    If it has three raised up bosses down in the lifter valley, the YES... It is a roller cam block. Usually just above the casting number (drivers side, back end, on the bellhousing) there will be the displacement of the engine expressed in Litres (5.7.) Then it would in fact be a late roller cam 350 (or as hillbillies call them "Treee Fitties")

    Pull that plate of the side of the block, if you can stick your finger up in there and feel a hole (or see it) thats where the fuel pump rod goes. If thats the case, then you have a roller cam block with the hole for a fuel pump eccentric. That means you can have a mechanical fuel pumped roller cam 350 /forums/images/graemlins/grin.gif

    The heads that are on it are probably TBI's if it came out of any kind of truck. They'll have the 7th bolt on the exhaust (two are doubled up, right next to eachother for a final count of 7) and on the intake side it'll have 6 bolts, although unlike an earlier CSB, the center two right by the exhaust gas crossover will be drilled at a different angle.

    If I were you I'd keep the heads and use them on your buildup, if you're looking for low end grunt. They're a fantastic head for "torquey" motors. Not much for stock cars that live up at six and a half grand though... Unless you want lots of pull right off the apex of the corner /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

    All you'll need is a set of lifters, links (that keep the lifters from spinning like flat tappets) a "spider," and a thrust plate (I've got both part numbers for them, they made them in a "wide" and "narrow" pattern.

    Let me know if you need any more input...
     
  17. 4DiggerDan

    4DiggerDan 1/2 ton status

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    Another thing... If you are planning on going mechanical fuel pump, MAKE SURE you call the cam grinder and ask them if their roller cams have the LOBE on the cam for driving a mechanical fuel pump. Lots of the companies out there DON'T have them on the "OEM" roller cams. When I say OEM, I mean thats the style of cam you want to put in the roller cam block. Not one that uses a thrust button like in the early Chevy's non roller block. The thrust plate in the later block is much more positive that using a cam button to keep the cam from walking. One of the big problems with putting a roller cam in the early block is getting the timing cover to seal (the cam button wants to push it AWAY from the front of the block) You usually have to bastardize something together to stick behind the water pump to keep your timing cover on. Even then, they work okay for a few months then start to dribble a little out of the timing cover.

    Of course we all know that Chevy's don't LEAK oil...... They MARK THEIR TERRITORY!!!! /forums/images/graemlins/grin.gif
     
  18. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    i plan on TBI, so a mechanical fuel pump will not be needed.
    the timing set i just bought is a double roller for a retrofit cam. why will it not fit a stock roller cam or why will it not fit a solid lifter cam?
    or are they just blowing smoke up my @$$?
    thanks for all your help man. i will have many q's to come.
    im going to pick up that block on saturday and then tear it down anr start the rebuild process.
    grant
     

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