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Author
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Topic: 66 289 heads
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IIblue74
Gearhead Posts: 162
From: memphis,tn
Registered: Aug 2000
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posted 04-13-2001 10:38 PM
   
I set up a deal today to get a set with stainless valves, double valve springs, etc. My block is a '71 302 with flat top pistons. Does anyone know what compression ratio this makes? Do I need different pushrods and will I be able to use my '71 rockers? What are the hi-po indicators again? What redline should this make me safe to with a stock bottom end (mexican casting)
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Moneymaker
Administrator Posts: 17471
From: Lyons, IL, USA
Registered: May 99
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posted 04-13-2001 11:47 PM
It depends on what cc's the heads are. HIPO's have 48 cc heads and will create more compression than the 54 CC "A" and "C" code heads.  ------------------
Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
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IIblue74
Gearhead Posts: 162
From: memphis,tn
Registered: Aug 2000
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posted 04-14-2001 04:29 PM
anyone else?
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74merc
Gearhead Posts: 733
From: Demopolis AL
Registered: Jun 99
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posted 04-14-2001 11:50 PM
around 10:1 with either head, depending on gasket thickness, whether the piston is notched for valves, etc.
find the casting numbers...
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IIblue74
Gearhead Posts: 162
From: memphis,tn
Registered: Aug 2000
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posted 04-15-2001 12:22 AM
my pistons are 100% flat with no valve relief or dish and the casting is C6OE. Thanks for the help [This message has been edited by IIblue74 (edited 04-15-2001).]
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n2oMike
Gearhead Posts: 1252
From: Spencer, WV
Registered: Jan 2001
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posted 04-15-2001 08:42 AM
It will be around 10.5 to 1. depending on the piston and how close the piston comes to the top of the bore at TDC. I built a similar engine for a friend several years ago. It was a 302 with ported 289 heads combined with a 224/236 @ 0.050" 110 lsa cam. He plunked a stock distributer and an E-Bok 750 carb in the thing. It ran strong, but required octane booster + premium unleaded. I think he could have tuned the ping out of it by richening the carb a little and installing an MSD billet distributer to adjust the timing advance. A larger cam would have bled off more cylinder pressure, and also done the trick... The engine ran well, winning more than its share of the stoplight grand prix, was reliable, and got 17-18 mpg in an 81 capri with a 5-speed. Good Luck! ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/motorcitymustang/cmml/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
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Moneymaker
Administrator Posts: 17471
From: Lyons, IL, USA
Registered: May 99
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posted 04-15-2001 11:33 AM
I don't know where you guys get your numbers from, but the C60E heads are 54 cc's. That coupled with a flat top piston would be a 10 to 1 "A" code style engine with stock .045 gaskets. Providing that the deck height was close. Steel shim gaskets would pick it up a 1/2 point or so. 48 cc heads is how FoMoCo got the HIPO to 10.5 to 1 compression.  ------------------
Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
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IIblue74
Gearhead Posts: 162
From: memphis,tn
Registered: Aug 2000
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posted 04-15-2001 12:48 PM
So, we've settled on 10:1 compression. Will I be better off putting the springs, etc. in my '71 castings or will it run on pump gas? You guys are helping a lot but there are still some unanswered questions and new ones keep popping up. My GPZ 750 came stock with 9.5:1 compression and liked pump gas fine but this is the first time I've tried rodding a v-8 so please keep the info coming. [This message has been edited by IIblue74 (edited 04-15-2001).]
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n2oMike
Gearhead Posts: 1252
From: Spencer, WV
Registered: Jan 2001
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posted 04-15-2001 12:49 PM
Remember Alex, this is a 302... not a 289 like you are used to working with. It has more swept volume, and builds more compression. Doing the math...
Swept Volume
306/8 = 38.25...
converting to cc's 38.25 x 16.38 = 626.5cc Clearance Volume
valve notches = 3cc
0.010" compression height = 2cc
head gasket = 9cc
combustion chamber = 54cc total clearance volume = 68cc compression ratio = (swept + clearance)/clearance (626.5 + 68)/68 = 10.21 Now, with zero deck height, clearance volume = 66cc (626.5 + 66)/66 = 10.49 So the real compression ratio is probably going to be somewhere between 10 and 10.5 depending upon how close the piston comes to the top of the bore, your valve notches, and the head gasket used. Factory ratings were often off. Flat top 289's (non-hipo 4bbl) were rated at 10 to 1, even though with everything added together, they didn't really have quite that much. Good Luck! ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/motorcitymustang/cmml/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
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Moneymaker
Administrator Posts: 17471
From: Lyons, IL, USA
Registered: May 99
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posted 04-15-2001 02:50 PM
OOPS! Never read the 302 part.  : I kept on staring at the "289 heads" thread topic. That WILL make a difference. ------------------
Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
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66302Stang
Gearhead Posts: 205
From: Mesa, AZ, USA
Registered: Aug 2000
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posted 04-15-2001 08:54 PM
Now I am scared. You are saying Ilblue74, will have 10.2:1 with a 302 with 289 heads. I have a 302, bored 60 over, with 65 289 heads. SO I have a 310. What's my compression? N20mike, will you do the math? Pistons have a VERY small valve notches, otherwise are flattop. Adam------------------
1966 Mustang Coupe
(soon)
....not yet Finished
302 bored .060 over
Sealed Power Rings
C5AE 65 289 Heads
10:1 compression
218/228 .471/.471 114LSA
65 2 barrel intake,carb
Stock msnifolds (for now)
Glasspacks (for now)
Dual exhaust w/ balance
C4 auto
3.20 rear end
2800lbs
Probably 200-275HP
Hopefully low 15's high 14's
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sigtauenus
Gearhead Posts: 1692
From: Beaufort, SC
Registered: Jun 2000
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posted 04-15-2001 09:20 PM
quote:
Originally posted by 66302Stang:
I have a 302, bored 60 over, with 65 289 heads.
What's the opinion on blocks bored out .060? I always heard of them having unpredictable overheating problems. Is there any truth to that? Also, since we are on the subject of 302's with 289 heads (yep, me too), is there any disadvantage to having unmatched heads? (thing I've asked this here before, but cannot remember) One head is a C5 casting, the other is a C7 casting, the only difference I can tell is the hole for the pushrod, but I use rail rockers on both sides so that doesn't matter. As far as I can tell combustion chamber is the same on both heads, and the specs are the same too. As for IIblue, your rocker question...your 71 rockers are the rail type, you can use them as long as the valves you put in the 289 heads are the longer type that stick up past the keepers for the rail rockers to fit on. Alex should be able to address that better, though.
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Moneymaker
Administrator Posts: 17471
From: Lyons, IL, USA
Registered: May 99
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posted 04-15-2001 11:30 PM
Overheating is an "old wives tale". You can safely bore a 289-302 to .060. I do it all of the time and have been for over 25 years. ------------------
Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
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66302Stang
Gearhead Posts: 205
From: Mesa, AZ, USA
Registered: Aug 2000
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posted 04-16-2001 10:50 PM
Yeah, actullay 60 over's do over heat. At least here in AZ they do. Thanks alex for the radiator, it keeps it cool, unless I drive very "agressivley" then it kinda heats up, not near what it used to. And it stays cool unless I REALLY REALLY get on it.
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69maverick
Gearhead Posts: 823
From: Thomaston,CT.
Registered: Jan 2001
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posted 04-17-2001 07:54 AM
As far as over heating! I never had a problem
but up here in the north its a little colder than arizona!  But there is a product called Water-Wetter that can be added to the
radiator that will help make it run cooler!
This stuff works!!
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ccode67
Gearhead Posts: 1275
From: douglasville,ga,usa
Registered: Mar 2001
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posted 04-17-2001 08:48 AM
I had some overheating problems with my 67 w/289, new 3 row radiator didn't help so I installed a Flowkooler water pump and high flow thermostat, no more overheating.------------------
67 stang 5 speed
91 f-150 xlt
98 explorer xlt sohc v-6
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brockjoe
Gearhead Posts: 928
From: Sioux City, Iowa
Registered: Oct 99
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posted 04-17-2001 09:27 AM
i have c60e's w/1.90int 160exh, on my 302 flat tops w/ reliefs i used the 302 push rods and the 289 rockers the cam has 490/520 lift no problems with clearance or rocker geomitry. ------------------
Joe
71 Coupe
302 w/2x4
73 Coupe parts car.
Boycott NASCAR
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sigtauenus
Gearhead Posts: 1692
From: Beaufort, SC
Registered: Jun 2000
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posted 04-18-2001 01:01 PM
Didn't push rod length change in 68 or 69? 6.800" to 6.850"? If lifters are the same, and rocker arm ratio is the same, wouldn't the longer pushrod give you a little bit more lift? Ok, not lift really, but open the valve more? I'm pretty sure the lifters stayed the same, not sure if the rockers were all 1.6:1.
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n2oMike
Gearhead Posts: 1252
From: Spencer, WV
Registered: Jan 2001
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posted 04-21-2001 09:17 PM
Anytime head swaps are performed, a quick check of the steam holes is recommended. These are the smaller (1/8" or so) holes in the head and deck surface. On a 289, they are directly over the bore towards the intake valley. On a 302, they are off to the side. These steam holes should match up. If they don't, and more often than not, they don't, they will need to be corrected. To do this, new holes will need to be drilled. Using the head gasket as a template, either drill matching holes in the head or the deck of the block. It doesn't matter which is drilled, as long as there are lined up steam holes when you're finished. I don't like boring a block any more than necessary. Thicker cylinder walls offer better ring seal and better cooling. I guess if you are "Hard Blocking" a race engine, it doesn't really matter, but for a streeter it does. Your mileage may vary. Good Luck! Compression ratio for a 0.060" 302 with 289 heads should still be right around 10.2 to 10.5 depending upon a variety of factors. You'll be pushing the limits of pump gas. Be sure to get good control over the ignition curve, and be sure the carb isn't too lean. Good Luck! ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/motorcitymustang/cmml/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
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