Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Roller cam in an older block?

Discussion in 'The Garage' started by camok5, Jan 6, 2007.

  1. camok5

    camok5 1/2 ton status Premium Member

    Joined:
    Jun 25, 2003
    Posts:
    959
    Likes Received:
    13
    Location:
    Buellton, Ca
    I have a pre 87 4bolt main block, 383 engine that I plan on rebuilding and want to know what it takes to make it a roller engine? What machining needs to be done and what parts might I need to convert it? Its going in my 87 blazer with a tbi setup.
     
  2. 1977k5

    1977k5 3/4 ton status Vendor

    Joined:
    May 26, 2003
    Posts:
    9,996
    Likes Received:
    134
  3. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,063
    Likes Received:
    70
    Location:
    Pleasanton, CA.
    You will need a roller cam, cam thrust button, different push rods, retro fit lifters. You will need to add a piece of metal to the timing cover to stiffen it up where the thrust button will ride against.
     
  4. MuddinManny

    MuddinManny Banned

    Joined:
    Oct 18, 2006
    Posts:
    1,106
    Likes Received:
    0
    Location:
    USA
    My 383 is being built out of an older block, I believe it's a '79. It's got roller everything, all the way through. Puts out 550 HP/550 Ft/Lbs. Torque. Here's the build date stamp on the block. It can be down. How, I'm not sure. The builder has kept it a "secret".

    [​IMG]

    Hope this helps.

    Manny
     
  5. Captainfab

    Captainfab 1/2 ton status Premium Member

    Joined:
    Mar 5, 2006
    Posts:
    468
    Likes Received:
    1
    Location:
    Coeur d"Alene,Idaho
    A couple of weeks ago I bought some info off ebay on how to retrofit '87 & up roller cam and lifters into a pre '87 block. I haven't done the conversion yet so I can't say if it really works, or how well. Of course this guy says it's totally awesome. What I have seen in the info looks to be not too complicated, and ought to work. I don't see it on ebay anymore but here's his email if you're interested tt5t@hotmail.com The engine he built when he compiled all this info was a TBI 383. He also does TBI chips I believe
     
  6. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,063
    Likes Received:
    70
    Location:
    Pleasanton, CA.
    Why would you "buy" info when it is here for FREE? I suppose that the guy is making a killing selling info and you got suckered into it but if it helps you in your project that's what counts.
     
  7. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    it was posted here before. The thing he bought talks about installing the newer style(87+), "Spider" in the valley of an older engine to accomadate the factory roller lifters. You also have to get the lifter bores machined flat so the retainers stay flat. Between buying the lifters, spider, retainers, and having the bores machined flat, I bet you spent as much as aftermarket lifters, if not more. Now granted, factory lifters ARE a better design. I've heard it said many times that you shouldn't let aftermarket roller lifter engines just sit there and idle a lot. Which in the offroad world, can be a lot of what we do. You are WAY better off buying a factory roller block in my opinion.

    Of course when I say "roller" I am refering to hydraulic roller in this case.

    Oh and you all missed another thing, you need a new distributor gear. Roller camshafts are made of harder material that will destroy a standard non-roller distributor drive gear. You can pick up a factory gear off of Scoggin-Dickey pretty cheap. Thats what I did.

    Original Poster- To convert your engine to roller, you need aftermarket lifters, valve springs(extreme ramp rates of rollers do require different springs in most situations), pushrods, distributor drive gear, cam button or other form of cam retainer(I really hate the idea of a cam button, its ****ing retarded to just have a piece of metal rubbing your timing cover to keep the cam in place...) and a new timing cover is a good idea(a thicker stronger one). Oh and of course the cam.

    Scoggin Dickey sells a kit with their own speced camshaft for the retrofit of roller to older engines: http://www.sdpc2000.com/catalog/4193/products/266438/SB-Chevrolet-Retro-HOT-Cam-Kit.htm
    however, I'd bet that cam is too wild for TBI. I think they base it off of the GM Hi-Perf LT4 Hot Cam, which is the cam I have for my 383, but is too wild for TBI.
     
  8. Captainfab

    Captainfab 1/2 ton status Premium Member

    Joined:
    Mar 5, 2006
    Posts:
    468
    Likes Received:
    1
    Location:
    Coeur d"Alene,Idaho
    I had no idea that same info was available here for free! The info was only $20, and yes I know that $20 is $20, but I thought it could be worth it to see what someone elso came up with. If nothing else to see what not to do.

    I agree with Sled Dog, If you want to use the factory roller setup, you'd be better off getting an '87 & up block. I got the info for possible use on a 406 I want to build.
     
  9. 1977k5

    1977k5 3/4 ton status Vendor

    Joined:
    May 26, 2003
    Posts:
    9,996
    Likes Received:
    134
    Helpful post :surepal:

    Grow some humility and stop pimping your junk everywhere
     
  10. MaxPF

    MaxPF 1/2 ton status

    Joined:
    Apr 13, 2006
    Posts:
    2,207
    Likes Received:
    0
    Location:
    Chandler, Arizona
    The problem there is that most of those blocks are 2-bolt main with fairly thin, pared-down main bearing bulkheads. Material was removed from the main webs (and elsewhere in the block) to reduce weight. Being a 2-bolt block doesn't bother me too much since a good 2-bolt block will handle a lot of power, but compared to the old 3970010 casting I have in my shed there is a LOT less metal in the critical areas of these newer roller blocks. At least, that is the case with my TBI block, and my buddy's late-90's L31 block. Then there are the folks who want to build a 400. The only 400 blocks that can take factory rollers are the $$$ BowTie blocks. Anyway, if someone has a good pre-87 block why not use it? I plan on using that old 70's vintage 4-bolt block to build my 383, and I plan on using factory roller lifters with custom retainers. I suppose it all boils down to how much power you want to make and what you already have in your personal inventory :D
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    Are you sure about that statement?

    3970010 (for instance) was either 2 bolt or 4 bolt. The casting wasn't different, it was the machining.

    If GM made 2 and 4 bolt 350's up until 2001 (and they did I suspect) I really doubt they would have had two different castings just to add a few more bolts.
     
  12. MaxPF

    MaxPF 1/2 ton status

    Joined:
    Apr 13, 2006
    Posts:
    2,207
    Likes Received:
    0
    Location:
    Chandler, Arizona
    I am sure of what I saw - there is a LOT less meat in the main webs on the two 2-bolt roller blocks that I have seen, compared to the old 010 casting I have. You could drill and tap it for 4 bolts, but you would break through the web and end up not having a lot of material to attach the outer bolts to. According to Mortec.com there were numerous different castings for 87-up, and some were 2 or 4 bolt. Hopefully they had more material in the critical areas on those blocks:dunno: If I wanted a factory roller block to make some serious power (400+HP) I would try to find one of those castings and verify that it had beefy main webs. Either that to pony up for the block used for the ZZ4 motor (which is a later production 4 bolt block) and hope it has beefy mains :D.
     
  13. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    I have seen 2 bolts with the thing spots he is talking about, but only once or twice. Majority(in my limited experience) are the same thickness and could be drilled for splayed mains or 4 bolt if you really wanted.
     
  14. texsub

    texsub Registered Member

    Joined:
    Jan 2, 2007
    Posts:
    20
    Likes Received:
    0
    Location:
    Amherst Texas
  15. MaxPF

    MaxPF 1/2 ton status

    Joined:
    Apr 13, 2006
    Posts:
    2,207
    Likes Received:
    0
    Location:
    Chandler, Arizona
    The blocks did have enough material just inside of the pan rails for splayed outer bolts, but IMO you would be polishing a turd. It would be better to simply find a block with beefier webs and straight 4-bolt mains...
     
  16. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    so you are saying all those guys building splayed 4 bolts are doing a bad thing and just polishing turds? Really not sure I get that. I'd really love to see comparison pictures or measurement. I can't for the life of me picture the two being different.
     
  17. sandawgk5

    sandawgk5 3/4 ton status

    Joined:
    Oct 28, 2003
    Posts:
    6,881
    Likes Received:
    1
    Location:
    Kitsap County PACNORWEST
    I have always been told it is stronger to splay a 2 bolt block than to use a stock 4 bolt block.

    I am not an engine builder just what I have read.

    Ira
     
  18. MaxPF

    MaxPF 1/2 ton status

    Joined:
    Apr 13, 2006
    Posts:
    2,207
    Likes Received:
    0
    Location:
    Chandler, Arizona
    No, I'm saying splaying those particular blocks with the thinned bulkheads would be a waste of money and time. Better off to use a beefier block, like one of the old castings with thick bulkheads or a Bowtie block.

    Since it was machined for rollers I was going to use my 91 block to build up until I saw how much metal had been removed from the main webs. Since that motor is still on the engine stand I will pull the pan and take some pics, and I will take some pics of my old 010 block for comparison so folks can see what I am talking about.
     
  19. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    I look forward to the posting. My dads got a 327 block upside down in his garage, so I'd have to assume something that old is beefier, if it was going to be.

    I have a picture of an oil pan resting on my engine while being built, but none with the pan off. :(

    I know exactly where you are talking about the thinning, in 1977 (and all later small block Olds) Oldsmobile actually "windowed" that area between the main cap "bolt hole" and the block wall. Yes, they are weak there, and somewhere I have a picture of a journal that was actually ripped right out of the block. :)
     
  20. MaxPF

    MaxPF 1/2 ton status

    Joined:
    Apr 13, 2006
    Posts:
    2,207
    Likes Received:
    0
    Location:
    Chandler, Arizona
    OK, here's the pics

    I finally got pics of the 2 blocks. The first is the 91 block out of my Blazer:

    [​IMG]

    As you can see, the casting number is 14093638. Mortec.com lists this as:

    CASTING#.....SIZE...YEAR...MAIN CAP BOLTS....NOTES
    14093638...350...87-95...2 or 4...Roller or flat tappet cam, one-piece rear seal
    That matches the description of my block. I have flat tappet lifters, but the block is fully machined for rollers. Here's a pic of the main webs:

    [​IMG]

    Unfortunately that was the best angle I could get for a pic, since the bottom end is assembled. As it was I had to pull the pan to take that pic - reuseable pan gaskets rock :waytogo: Anyway, you can see the shadow cast into the relieved area. This is one of the main areas where there is less material in the casting. Let's see what the other block has:

    [​IMG]

    The casting number is 3970010. I know the 3 looks like an 8, but it is definitely a 3. Here's what Mortec.com says:

    CASTING#.....SIZE...YEAR...MAIN CAP BOLTS....NOTES
    3970010....302.....69....4...Z-28 Camaro
    3970010....327.....69....2...Trucks and industrial
    3970010....350...69-80...2 or 4
    Anyway, here is the main bulkheads:

    [​IMG]

    It may be difficult to see the main differences in the pics, but look at how far the relieved area extends below the cylinder bore in the late casting compared to the 010 block. Not only does it extend farther, but it is thinner. If you look carefully, you can see that the boring bar was still cutting on the web in the 010 block, whereas the casting was thin enough on the 3638 block that the bar doesn't hit any material below the cylinder.

    Now, apparantly the 3638 block was made in 4-bolt versions as well as the much more common 2 bolt. I suppose if GM felt it was strong enough, then it probably is. I'm sure many people have used them in some pretty stout street motors without any trouble. OTOH, I don't recall ever seeing one used for a 360 sprint car motor (though the last time I messed with a sprint car motor was 10 years ago). Most used 010's or other similar vintage blocks converted to splayed 4 bolt caps, or they ponied up for a BowTie block. In either case, they routinely made 600-650HP with these motors, turning 7500-8000 RPM, and I never heard of block failures.

    Anyway, that's my loose change on the subject. I don't claim to be an expert on GM engine blocks, I just know what I have seen in my limited experience and heard from reputable builders. I'm sure there is a reason Mr Janke used an older block for Manny's 500HP 383 rather than a late model block. Or maybe that's what he had lying around? I don't know. All I do know is that I am going to use the older block, even though using factory style roller lifters is going to be a PITA :D
     

Share This Page