Vintage 302 chevy.

Discussion in 'Engine Combos and Dynometer Database' started by rjs89ia, Feb 16, 2016.

  1. rjs89ia

    rjs89ia Well-Known Member

    Hi all, I purchased this 302 back in 2014, the previous owner had it disassembled and stored in plastic containers. The story he told me is that the person he got it from had it in a sand drag jeep. That person had recently rebuilt the engine and had it running and idling and it just quit/locked up and it was pulled and sat until it was purchased by the guy I got it from. He ironically couldn't remember the name of the person or where he got it from, just that little bit of information. I can believe that it did sit for a long time with water in some of the cylinders because there's a considerable amount of damage in some the cylinders. Whether or not it was running and locked up I don't know, it may have been a blown head gasket or a crack.

    Here's some links to my photobucket albums that do a great deal more explaining than I can on my break. Chevy?sort=3&page=1

    I did try to put a description with most of the pictures in the larger album as far as what and where it was but I ran out of steam this past weekend. There isn't anything that's jaw dropping but it's neat.

    I will try to get some more detailed info on here later. Thanks for looking.
  2. 87vette81big

    87vette81big Guest

    Its an Aluminium Connecting Rod Vintage Race Engine.
    They are meant for Max Drag Racing Efforts.
    Though I know of one friend that had a 355 SBC With Aluminium Rods in his old 1981 Camaro. Nitrous On it was a Street Racing Terror.
    Nearly Unbeatable at the time.
    10-second track car.
    He racked up 10,000 miles on the street and track. Bill Miller Aluminium Rods were inside.
    But when aluminium rods fail its bad news.
    Since you have little history on the engine its Risky reusing the AL Connecting Rods.
    Steel Rods are best for Street Use.
    Titanium can be used but Super Expensive today.
  3. 87vette81big

    87vette81big Guest

    Lunchtime I will look at more of your photos .
  4. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    brief look over pictures, youve obviously got a good basic selection of parts if the block and crank pass a close inspection and once the crank journals are polished
    with a 1500 grit belt after cutting if required to the correct diameter

    all the rockers obviously rubbed on valve spring retainers so Id think about swapping to the beehive style with the smaller retainer for clearance


    if you change the rocker ratio the push rod alignment changes and you might need a LUIS TOOL to lengthen the cylinder head clearance slots in the cylinder heads.
    be sure to check clearances carefully like coil bind,and push-rod to guide plate alignment and clearances ,verify the rocker slots don,t bind on the rocker studs as this is a common problem with stock stamped style 1.6:1 ratio rocker, verify the push rods don,t bind in the slots in the cylinder head, if they do even for an instant at one point in the rockers arc, they can bind the lifter rotation on the cam lobe and cause the cam to wipe, out the lobe and the lobe & lifter contact area resulting in a quickly failed cam,and/or restrict oil to the rockers
    looks like stripped crank snout threads?
    Looks like un-even journal diameter due to improper polish
    these journals may need to be cut and polished to a standard under-size for matched sized bearing

    retainers show obvious valve float bounce damage


    cam bearings are always replaced once removed but note these are damaged

    looks like valve pockets were cut too deep then brazed and re-machined

    looks like steam damage , on the piston below,, perhaps a leaking head gasket?
    ID have a machine shop you trust check the block and heads for cracks
    if they suggest boring the block youll need new pistons and rings and Id strongly suggest having the block walls sonic tested as a stock 2 bolt main blocks not ideal as an investment for putting a great deal of cash into in machine shop labor

    looks like some one beat the crap out of pilot bearing

    some valves show what looks like steam etching damage

    porting the runners here could add measurable power
    like below

    Last edited: Dec 25, 2018
  5. Indycars

    Indycars Administrator Staff Member

    Good start .......what's your budget and time frame for getting this project done?
  6. rjs89ia

    rjs89ia Well-Known Member

    Thanks. I haven't really thought about a budget but I'm willing to spend what it takes to make it right even if it takes a while to get everything to build it. Right now I'm still trying to gear up and get my shop in line so it makes things easier. I'm trying to build a clean room to help minimize the dust and dirt.
  7. 87vette81big

    87vette81big Guest

    Look over the Valvestem Keeper Grooves Carefully .
    With Valve Float the Keeper Grooves on the Valvestems almost always take a Severe Beating.
    You will spot the damage easily if present.
    New Valves are affordable for SBC.
    Manley Stainless Steel Replacement & Manley Pro Flow Valves.
    Ferrea 5000 series Stainless Valves are an excellent choice also.
  8. rjs89ia

    rjs89ia Well-Known Member

    The aluminum rods were almost a deal breaker for me, it kind of caught me off guard because I didn't know anything about them. I consulted in a friend that races a blown alcohol BBC rail and said the rods should be fine. He also uses "used" brooks rods in his engine. As I was looking over the engine I started to see the engravings in the block and the cylinder heads and decided this thing had some professional work done to it at some point. I have since learned a great deal about 302 chevy's and aluminum rods. This engine does have nitrous provisions but I don't plan to use it, at least I think that.
  9. rjs89ia

    rjs89ia Well-Known Member

    Thanks for looking Grumpy, the rockers had actually been purposely clearanced, they are beat though from use. I found a bunch of cracked rollers and the the trunnions/shafts in them are chipped away where the adjuster nuts seat. I have looked at the beehive springs but that's still an area where I have little knowledge about selecting the correct pieces. I was planning to use the springs that had been called for on the cam spec card but if I can find something that meets the requirements and is lighter with more clearance then that would be great too.

    I checked the threads in the crank snout and they are good. The mains look uneven because I wasn't perfectly straight on with my camera so it makes it looks angled. I had done a quick check of all the journals with a caliper and the mains were 2.2865 across the board and the rods 1.9865. The crank is already .010,.010 under. the discoloration in the one picture I believe is a layer of corrosion from water being left in the engine after a head gasket blow out and no one ever drained the engine after that happened and it sat for a very long time until it got to the guy I bought it from who finally tore it down. I can't say much about the pilot bushing other than it will be replaced. I don't know how long that paints been on there but it doesn't look like there's been any drive line components attached to the crank in a while.

    The damage on the cam bearing was probably from me. I tried to snafu the first one out then I decided to go buy a socket big enough to drive them out without hurting myself or the block. This was just to get the block bare for when I take it to a machine shop.

    The 492 heads were worked on by slovers porting, I just assumed the seats were cut on purpose to fill the thin area in to build a stronger base for the big springs.

    The pistons and valves seem to have no pitting to extreme pitting. Steam pitting is something new to me so i'll remember that. I just figured that since it had a nitrous setup that it was bringing those surfaces to a boiling point.

    I've thought hard about whether I should use the 2 bolt or not. The block has some damage in the cylinders and I'll be sure to leave instructions for the machine shop to stop and contact me if there's any concerns about dependability. I do have an alternate 4 bolt medium journal block that I could bring up to speed if needed.

    The intake is something I'd like to try to leave alone, the gains I'm sure would be worth it but I still haven't found another intake like it. It's a weiand 1982 pro hi-ram and out of the 1 or 2 smallblock manifolds I've been able to find mine was the only one that wasn't an air gap and had the "pro ram" ports. I don't know if this is something to be proud of but at this time I don't feel comfortable with porting it. Maybe after I get it put together and running I might take it that next step and have it done.

    The machine shop I plan to go to is JD machine in Lake Havasu, AZ. I've read an article online about them and there's a corvette restoration company I believe in phoenix or tucson that exclusively uses them for period correct down to the nuts and bolts restorations on their engines. My friend with the alcohol bbc mentioned in the post above used them before as well and recommended them. They also have a dyno that would make it a lot easier to dial in the carburetors.
  10. Indycars

    Indycars Administrator Staff Member

    You might find a couple of my spreadsheets useful, especially the one that
    tracks machine shop costs and sequencing. All you have to do is put a Y in
    the cell adjacent to the machine operation that you want.


    Some other useful spreadsheets for assembly.

  11. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    BTW just some info
    the reason that tunnel ram intake was designed like that was that back when the holley dominator carburetors first came out , it was felt that a tunnel ram that allowed the carb to be bolted to the intake so that each carb throttle body venturie should feed each individual runner separately, that's why the lower intake plenum bolt spacing, matches the dominator bolt mount spacing, this in theory provides an individual runner intakes tunning advantages but the holley dominator throttle bore diameter is not large enough in cross sectional area to provide adequate flow rates for much over a 383 engine displacement in that config so a spacer plenum was quickly added to allow multiple throttle bores to supply each intake runner port entrance.
    obviously the dominator carb model with the individually adjustable 4 corner idle screws was required, and theres 750 cfm,1050 cfm , 1150 cfm and 1250 cfm versions of the dominator carbs, and a direct 1:1 secondary throttle blade linkage kit that made each throttle open simultaneously was required
    [​IMG] carburetor models carburetor models&page=2 carburetor models&page=3

    obviously if the intakes set up for use as a single runner intake tuning the cam timing, exhaust scavenging and displacement to the engines compression and gearing and throttle bore size is critical to making it function effectively in the intended rpm range


    Last edited: Feb 17, 2016
  12. rjs89ia

    rjs89ia Well-Known Member

    Thanks Indycars the spreadsheets will make it a lot easier to keep track of everything.

    Grumpy, I've read your whole thread on tunnel rams that's what led me here. I do plan to leave the open plenum on the top and run the 660 carbs.

    According to an archived page that Holley was able to provide me they recommended using 600cfm carburetors for up to 327ci's.

    I was thinking of using a port extension to help individualize the mixture from each venturi but still allow for some sharing. Would this be worth wasting the time on? I did like the idea of the screens and the divider in the plenum.
  13. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    a pair of 600 or 660 holleys has always worked rather well for me in the past , but your not limited to holleys
    keep in mind a tunnel ram intake is designed to operate in the 3500-rpm-8000-rpm power band so the cam will need to be designed to operate in that same rpm band, that will generally mean a solid lifter valve train and a set of rocker stud girdles and roller rockers.
    now I don,t know what your planing but in the past I,ve used a CRANE 110921 solid lifter flat tappet cam, and a manual transmission and a 4.11:1 rear gear, ratio, in the 1968-1967 302 Z28 engines

    Last edited: Dec 25, 2018
  14. rjs89ia

    rjs89ia Well-Known Member

    I've kind of grown to like the 660's they to me are basic and simple to work on and I've piled a wealth of information on them. Plus I already have them.
    Last edited by a moderator: Sep 7, 2017
  15. rjs89ia

    rjs89ia Well-Known Member

    My 327 block is already .030 over and a lot of what I've read has been opposed at going any bigger than this. What should be a minimum wall thickness if I go to .040? There's so many different opinions about it. Should I only be concerned about sonic checking the thrust side of the cylinder, both top and bottom or the entire thing? According to some similar cams in the crane catalog they recommend 12.5:1 or better compression.
  16. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    have your block carefully sonic tested , read the links , you can get away with rather thin bore walls in less stressed areas ,for awhile, but if you find any place under about .o90 I would not put any more cash into the block (personally Id want thicker as in double that or .180 minimum.) if you intend to seriously thrash the engine, stress is cumulative, like bending a steel coat hanger over 90 degrees then back strait, the first couple times it handles the stress, but repeat the process over and over and at some point the wire just breaks off

    and remember the bore wall is subjected to hundreds of PSI of cylinder pressure 50-70 times a second,

    if we calculate that 700 psi at peak cylinder pressure a 302 has a 4" bore so roughly 12.6 square inches of piston surface , over 8800 ft lbs of force on the crank and thats not counting inertial loads

    an example of a sonic test on a stock block bores .060 over bore


    notice several areas, A-E where the block walls less than .100 thick
    Last edited: Feb 17, 2016
  17. 87vette81big

    87vette81big Guest

    Rick has had very Good Luck with his Dart SHP Block.
    The Dart Little M Block is good for 2,000 HP. They are Pricey The Little M.
    Either way I would aim for 400+ cubic inches.
    The only way its worthwhile running High Compression is if your Drag Racing.
    12.0 -15,0 :1. Race Gas. Alcohol fuel.
    Vintage Iron Pontiac High compression.
    Race gas is still expensive.

    301 SBC Is based off a 283 SBC Block.
    I recall hearing you overbore it .100-.125".
    Lots of Meat in early SBC 283 Cylinder walls.
    Ditto for early Pontiac V8. 1955-1961 & Up to 1965.
    They over built in the early years.
  18. Indycars

    Indycars Administrator Staff Member

    What the hell does that mean ..... good luck ??? I guess I didn't know my ass
    from a hole in the ground when I built that engine? Must be what you are saying!
  19. 87vette81big

    87vette81big Guest

    Touchy Tonight You are Rick.
    Good Luck to Me Means The Engine Never Failed or Blew up.
    Just How Racers Talk at the Tracks.
    Looking at Vids posted on Max.
    Post here later.
    Keep Grumpy & You & others Entertained .
  20. rjs89ia

    rjs89ia Well-Known Member

    I have looked at the shp blocks and thought it would have been nice if I had just started there instead of buying this engine. I like the idea of bringing this engine back to where it once was with as many of the original parts as I can. I don't disagree that I would be money ahead by having all the nice new stuff but that wouldn't make it the same. I don't plan on thrashing this engine but it will get turned up like its been built for. I've got two 64 chevelle 300's and I plan to make one of them a Nostalgia race car and hopefully run it in vegas and maybe lake havasu if they ever build a strip like has been said.

    If the block checks out ok I would like to have the mains pinned like in one of the threads grumpy posted above. I wish there was a better 2 bolt cap that I could put on it but I haven't found any one that makes just a 2 bolt performance cap for all the mains unless you just buy a bunch of forward caps and put them on 2-4. I've thought about strapping the stock caps but I don't know if the machine shop will do something like that. I know it would be best to go to a splayed cap instead of a 2 bolt just to be done with it but I'm not sure I want to do that yet.

    Overall if this thing lunches out at 8500 then at least I can say I enjoyed doing it. But I will try to do the best I can to make sure everything goes together correctly and smoothly to ensure it lives for more than a day.

    1,3 and 8 have water damage in the cylinders, If all the other cylinders were to check out and not need bored would it be a good idea to sleeve those three cylinders and have them machined to match? Any opinions about sleeves?

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