Budget 302 Build

Discussion in 'General Maverick/Comet' started by stumanchu, Dec 23, 2021.

  1. stumanchu

    stumanchu Stuart

    Joined:
    Feb 2, 2016
    Messages:
    1,375
    Likes Received:
    556
    Trophy Points:
    338
    Garage:
    1
    Location:
    Portland, OR
    Vehicle:
    74 comet, 70 Olsen step van, 2005 Scion xB
    OK, so we all know by now that I try do do as much as I can with the few dollars I get to spend. My latest project is the 302 that was pulled to make room for the "Junk motor" roller 302 built mostly from P&P parts. The Budget 302 is a 1971 "Torino" block, with no ridge and faint crosshatch even in the middle of the cylinders. It is also standard bore. 2 of the pistons have pock marks all over the top, and look horrible. All the pistons are between .o38 and .o42 DOWN the hole. Yuck. The compression height on said pistons is 1.610. They are stock bore Ford 302 pistons.

    What I want is pistons at deck height, or a little more. What I dont want is to spend money on decking the block. I do need to spend money on new standard bore pistons....if in fact the bores measure out to be useable without boring. That is yet to be seen, as I need to acquire a bore measuring tool. In the mean time, I did pick up a set of 289 rods attached to 289 pistons for 20 bucks. According to what I have read, the rods are .065 longer than 302 rods. If my new, cheap pistons have a compression height of 1.585, and I started about .040 down from the deck, that would put me .065 down the hole, and a 289 rod would put me at deck height. A rod that is .065 longer than stock can hardly be called a "long" rod, but it is a step in a good direction and will give me the deck height I want.

    Ultimately, I want to get as close to 10:1 as I can, for several good reasons.....and have a quench distance of around .039. I will use the "doorstop" ported heads after they get milled enough to give me 10:1. Cam will be hydraulic flat tappet, and have an LCA of around 108 or so....with duration around 218. Upgraded valve springs, factory rail rockers, (not optimum, but the heads came with new valves that have the long stems already). I also plan to "pin" the rocker studs.

    If I can use the block without machining, and possibly just honing, and cleaning of the oil passages, I could end up with a decent engine for less than the roller 302 that gathered its innards from the P&P junk piles. I know I am not asking for advice here, but comments and advice are always welcome as I still consider myself a newb at this stuff. I do it because I find it entertaining and fun. I do not know where this motor will live when its done. It might just hang out in the garage and be a cool, blue decoration.
     
    Mustang1989 likes this.
  2. jasonwthompson

    jasonwthompson Member

    Joined:
    Mar 25, 2012
    Messages:
    1,327
    Likes Received:
    450
    Trophy Points:
    196
    Location:
    Carrollton TX
    Vehicle:
    72 Comet
    Know you are going on the cheap, so to speak. However you may want to look at a set of Comp Cams 1450-16 1.7 roller tip rail rockers. The taller ratio gives a bit of added lift. If your 289 rods do not work out, let me know as I may have a set of 5.0 H.O. standard bore flat top pistons.
     
    rickyracer and stumanchu like this.
  3. stumanchu

    stumanchu Stuart

    Joined:
    Feb 2, 2016
    Messages:
    1,375
    Likes Received:
    556
    Trophy Points:
    338
    Garage:
    1
    Location:
    Portland, OR
    Vehicle:
    74 comet, 70 Olsen step van, 2005 Scion xB
    I did not realize there was such a thing as roller tip, rail rockers. A 1.7 ratio, at least on the intakes, would speed up the opening of the valve which would give it a little extra time to fill the cylinder through the 1.78 valve. Increased lift has no benefit on my flow bench with the tiny valve. In fact, flow with the valve removed was barely increased, but there are a few respectable builders out there that swear by maximizing lift. Engine building fascinates me for the very reason that even differing philosophies about it still produce results; people keep learning stuff, and improvements are made even after so many years of having them under our noses.
     
  4. jasonwthompson

    jasonwthompson Member

    Joined:
    Mar 25, 2012
    Messages:
    1,327
    Likes Received:
    450
    Trophy Points:
    196
    Location:
    Carrollton TX
    Vehicle:
    72 Comet
    I have been using the roller tip rails for a couple of years or more on a basically stock 5.0 H.O. with early 351W heads, and have had no issues.
     
  5. TeeEl

    TeeEl Member

    Joined:
    Oct 25, 2019
    Messages:
    730
    Likes Received:
    468
    Trophy Points:
    162
    Location:
    Colorado
    Vehicle:
    '73 Ford Maverick Resto-Mod
    I have roller-tip rail rockers on my Maverick. They're easier on the valve stem tips, but otherwise not much better than standard rocker arms. They don't even compare to full rollers. You are limited on lift with the rail-type (like .500" max, however anything over .450 on stock heads is useless anyway) and they are noisey (they make a "chicka-chicka-chicka" sound at idle). They're basically a waste of money. 'Only reason I have them is I got 'em for free.

    Personally, I would bore that motor .020 or .030. It's really the only way to do it right...
     
  6. stumanchu

    stumanchu Stuart

    Joined:
    Feb 2, 2016
    Messages:
    1,375
    Likes Received:
    556
    Trophy Points:
    338
    Garage:
    1
    Location:
    Portland, OR
    Vehicle:
    74 comet, 70 Olsen step van, 2005 Scion xB
    Are they 1.7 or 1.6? do you have stock heads? And if you dont mind my asking, do you recall what brand they were?
     
  7. TeeEl

    TeeEl Member

    Joined:
    Oct 25, 2019
    Messages:
    730
    Likes Received:
    468
    Trophy Points:
    162
    Location:
    Colorado
    Vehicle:
    '73 Ford Maverick Resto-Mod
    They are Comp Cams Magnum roller tip. 1.6:1 ratio. They work fine, but I wouldn't spend my money on them. I would have gone with full roller, but this was a "budget build" 14 years ago...
     
  8. stumanchu

    stumanchu Stuart

    Joined:
    Feb 2, 2016
    Messages:
    1,375
    Likes Received:
    556
    Trophy Points:
    338
    Garage:
    1
    Location:
    Portland, OR
    Vehicle:
    74 comet, 70 Olsen step van, 2005 Scion xB
    all rods and pistons removed. #4 rod bearing looks like like it was ready to fail. It was badly worn, the cap was discolored with a blackish color, and the bearing itself was distorted to the point that it would not conform to the shape of the cap when un-torqued. The crank journal was un-scored and shiny though. All the rod bearings had a C5 ford part #
     

    Attached Files:

  9. dyent

    dyent Member

    Joined:
    Jan 29, 2012
    Messages:
    1,144
    Likes Received:
    432
    Trophy Points:
    258
    Location:
    vancouver bc
    Vehicle:
    1973 Comet 2 dr., 302 w/AR aluminum heads, Toploader 4 spd, 9" Trac-Lok w/3.70
    Hi Stu!
    Even though the crank journal looks nice, I would still have it checked for "roundness" and/or if needed, ground and polished.......have a great New Years!
    Cheers,
    David
     
    mojo and stumanchu like this.
  10. stumanchu

    stumanchu Stuart

    Joined:
    Feb 2, 2016
    Messages:
    1,375
    Likes Received:
    556
    Trophy Points:
    338
    Garage:
    1
    Location:
    Portland, OR
    Vehicle:
    74 comet, 70 Olsen step van, 2005 Scion xB
    Main bearings : some wear, but no burns? Is this typical? 20211228_190132.jpg
     
  11. dyent

    dyent Member

    Joined:
    Jan 29, 2012
    Messages:
    1,144
    Likes Received:
    432
    Trophy Points:
    258
    Location:
    vancouver bc
    Vehicle:
    1973 Comet 2 dr., 302 w/AR aluminum heads, Toploader 4 spd, 9" Trac-Lok w/3.70
    Bearings #3 & #4 already worn down to copper, so only matter of time before something would have happened, you probably saved the crank! Just curious, what 2 pistons had the "pock marks", was one of them #4?
    David

    PS Re: 289 rods w/302 crank ala Boss 302, just have to play around with selecting correct piston to achieve what you want.......
     
    Last edited: Dec 29, 2021
  12. Mustang1989

    Mustang1989 Member

    Joined:
    May 11, 2020
    Messages:
    339
    Likes Received:
    222
    Trophy Points:
    127
    Location:
    Corpus Christi, Tx
    Vehicle:
    1994 Chevrolet 383 Silverado
    Looks like you’ve got a good project going Stu. Couldn’t help but notice that you were using the stock heads with the 1.78/1.45 valves and have 58 cc combustion chambers.
    I also see that you’re looking at some roller rockers and a few other valvetrain items.
    Since you plan on a budget build have you considered a set of GT-40 heads with 1.84/ 1.54 valves and a 63cc combustion chamber? You can pick a set of these bad boys up for around $600 and the benefits you’ll get are definitely worth it. See attached pics. $600 free shipping from eBay.
     

    Attached Files:

  13. Mustang1989

    Mustang1989 Member

    Joined:
    May 11, 2020
    Messages:
    339
    Likes Received:
    222
    Trophy Points:
    127
    Location:
    Corpus Christi, Tx
    Vehicle:
    1994 Chevrolet 383 Silverado
    I meant to include this in my post earlier, you’ll lose some on your compression ratio due to the larger combustion chamber size that the GT-40 heads have but you’ll gain a TON more in flow numbers AND you’ll be able to run it on pump fuel.
     
  14. Krazy Comet

    Krazy Comet Tom

    Joined:
    Sep 13, 2012
    Messages:
    7,561
    Likes Received:
    2,319
    Trophy Points:
    531
    Garage:
    1
    Location:
    Chesapeake VA
    Vehicle:
    1972 Comet GT clone 306 . 1969 Fairlane Cobra 428CJ 1988 T-Bird awaiting 331 ..
    With two main bearings heavily into copper, I'd say crank is out of round or block is warped. With #4 rod bearing worn, something is wrong. A oil problem should have also effected #5 main.
     
    Mustang1989 likes this.
  15. Mustang1989

    Mustang1989 Member

    Joined:
    May 11, 2020
    Messages:
    339
    Likes Received:
    222
    Trophy Points:
    127
    Location:
    Corpus Christi, Tx
    Vehicle:
    1994 Chevrolet 383 Silverado
    Yikes! I didn’t pay close enough attention earlier but Tom’s definitely got a point.
     

Share This Page