dartfreak75
Restore it, Dont part it!
That is the intake abdc numbers on the cam card that you are referring to correct?
65 Barracuda 318 Rebuild, Cam, timing, lifters maybe a kit?
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nm9stheham
Well-Known Member
Been away from this party for a while....OP, I would consider the 60779 Edelbrocks as an investment for the future. Your'e going to lose no more than .25 point of compression going to those over the present 273 heads, which are likely around 60 cc's in chamber volume. (57.3 cc is the NHRA blueprint spec, and is small than typical factory head volume.) AND, if the prior rebuild used standard Felpro 8553PT head gaskets, then the CR is going to INCREASE over what you have if you use the Edelbrocks and a thinner .028" head gasket (Mr Gasket PN 1121G).
302's are a cheap alternative but have around the same chamber volume as the Edelbrock's, so there is no compression advantage there. They are a cost advantage now, but will be a long term HP dis-advantage due to less breathing by far than the Edelbrocks. But, that depends on how far you want to go long term..... the 302's might be fine for your intended use.
So, IMHO, IF you have the coin to spend, and want to look long term towards more torque/HP, then I'd say slap the Edelbrocks on with the thin head gaskets, put in a mild cam and new chain, and go. As suggested, you can go back later and replace pistons. OR, maybe better yet, build another short block (318, 340, 360) and do it up right for how you want to use the car and build it around transferring those Edelbrocks onto the new short block. They are known good pieces for 400+ HP OOTB, when supported with good intake and exhaust breathing.
302's are a cheap alternative but have around the same chamber volume as the Edelbrock's, so there is no compression advantage there. They are a cost advantage now, but will be a long term HP dis-advantage due to less breathing by far than the Edelbrocks. But, that depends on how far you want to go long term..... the 302's might be fine for your intended use.
So, IMHO, IF you have the coin to spend, and want to look long term towards more torque/HP, then I'd say slap the Edelbrocks on with the thin head gaskets, put in a mild cam and new chain, and go. As suggested, you can go back later and replace pistons. OR, maybe better yet, build another short block (318, 340, 360) and do it up right for how you want to use the car and build it around transferring those Edelbrocks onto the new short block. They are known good pieces for 400+ HP OOTB, when supported with good intake and exhaust breathing.
A common sense approach! I like it.
nm9stheham
Well-Known Member
Tnx, TMM... just trying to work with the OP's thoughts and preferences, and optimize around that. He does not seem to be in the place to change pistons at this time, as he mentions getting on with the restoration. IMHO, it helps to explain the +'s and -'s of each approach; a few people just want a formula, but most folks want to have at least some idea of the 'why'.
OBTW, OP, cam timing as noted, WILL make a difference in throttle response and driveability in daily driving use. So, if you can stand a bit more work, then see if you can swing the time to set the cam timing. It requires a degree wheel (can be printed from online patterns, or bought) and a borrowed or bought dial indicator, and is most easily done with the intake and/or heads off.
OBTW, OP, cam timing as noted, WILL make a difference in throttle response and driveability in daily driving use. So, if you can stand a bit more work, then see if you can swing the time to set the cam timing. It requires a degree wheel (can be printed from online patterns, or bought) and a borrowed or bought dial indicator, and is most easily done with the intake and/or heads off.
dartfreak75
Restore it, Dont part it!
Could the flow edlebrock heads be achieved by porting 302 heads? Or will stock eddys still outflow ported 302s?
Bighead440
Well-Known Member
I'm betting that the OOTB Eddy's will outflow the max effort "302's" just because the smogger 318 heads start out small valved and with the tiny port window.
dartfreak75
Restore it, Dont part it!
I was just wondering like on a budget or a car you dont want aluminum heads on if the 302s could match. What are size valves are in a factory eddy?
I personally don't like the look of aluminum heads I guess I'm weird but I'm also not a racer I like an authentic and original appearance engine in a classic car.
Wyrmrider
Well-Known Member
Outflow? not a lot of help to a low compression motor High flow takes a higher flow cam to work together
Big cam on small heads kills low end and heads do not flow enough to really help-- a class race only solution
Big heads can work with small cam if heads have some velocity (not the Boss 302/Boss 429 solution)
The 302 may out velocity the Edelbrocks but the Edelbrocks may be a better balance of velocity and flow
X J 915 are example of better flow but lack of velocity kills even if milled small
check the Stan Weiss site and report back comparisons
there are several threads on home porting 302's
consensus is 302 OK if DIY not OK if you have to pay someone to do it
7 or 8 angle valve job then hand blend, narrow the valve guide- the usual stuff, back cut the valves
I did a set with 1.94 valves cut down with 30 degree seats sitting where the top cut was equal 45 and 60 - worked well but not flowed, cleaned up the flash, not much else
under half inch lift cam this was on a 360 motorhome
Big cam on small heads kills low end and heads do not flow enough to really help-- a class race only solution
Big heads can work with small cam if heads have some velocity (not the Boss 302/Boss 429 solution)
The 302 may out velocity the Edelbrocks but the Edelbrocks may be a better balance of velocity and flow
X J 915 are example of better flow but lack of velocity kills even if milled small
check the Stan Weiss site and report back comparisons
there are several threads on home porting 302's
consensus is 302 OK if DIY not OK if you have to pay someone to do it
7 or 8 angle valve job then hand blend, narrow the valve guide- the usual stuff, back cut the valves
I did a set with 1.94 valves cut down with 30 degree seats sitting where the top cut was equal 45 and 60 - worked well but not flowed, cleaned up the flash, not much else
under half inch lift cam this was on a 360 motorhome
Wasn't there a section on the engine bible, where ported 302's made more HP/TQ over a set of 2.02 J heads on a 318? I have to look when i get home tonight. Something about the port velocity and chambers.
I think I remember reading about that as well.
nm9stheham
Well-Known Member
Check out the Shady Dell site on this. Can't tell you how well that set up is calibrated; the low lift stock flow numbers are different than on the 1wild&crazy 318 thread, but the high lift stock flow numbers are pretty close, so probably the calibration is reasonably good.
And can't tell you how much this costs...
Shady Dell Speed Shop
dartfreak75
Restore it, Dont part it!
That is cool info. Iv always been a minimalist I like to get the most I can out of the least. If that makes sense. Anyone can make big power by throwing tons of money and aftermarket parts at an engine I like to see big power by modifying and tuning factory available parts.
Pictures from my engine book that I have had since the mid 80's
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HYUP
I"ll say it again forget the Eddies.
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Is that a Mopar Performance book?
Yes, it's the Mopar Performance Engine book. Some call it the bible. Everyone should have one. Best Mopar book I have.
Here's s'more of that Engines: 318 Street Recipes
dartfreak75
Restore it, Dont part it!
So according to that book the 302 heads are not swirl port heads? Am I reading that right?
They are in fact Swirl port heads.
The 302's and the 308's were swirl port.
dartfreak75
Restore it, Dont part it!
That is some good info right there!!! Thanks
From a Hot Rod Magazine article: Swirl Port Heads
Chrysler’s small-block cylinder head design changed very little until 1987 when the 302 casting (last three digits of the casting number), commonly known as the swirl port, was introduced. While the 302 casting, as well as the later 308 casting, were most commonly found on low-performance 318s, they shouldn’t be overlooked for a performance build. Even with small 1.75-inch intake and 1.50-inch exhaust valves, the design of this head’s heart-shaped quench-style combustion chamber makes it a good choice for mild to moderate performance. An engine with these heads in stock form will outperform an engine with stock X or J castings simply due to the improved combustion chamber design. Additionally, these heads have hardened valve seats, which make them compatible with unleaded fuel. The swirl port heads were utilized through 1991 (302 casting) and 1992 (308 casting) and respond well to port and bowl work, offering better power potential than all of the earlier small-block heads. Another nice feature of these heads is they utilize valvetrain and intake manifolds common to early small-blocks, so parts are readily available. Simply bolt these heads to your small-block and enjoy the extra power they provide.
Chrysler’s small-block cylinder head design changed very little until 1987 when the 302 casting (last three digits of the casting number), commonly known as the swirl port, was introduced. While the 302 casting, as well as the later 308 casting, were most commonly found on low-performance 318s, they shouldn’t be overlooked for a performance build. Even with small 1.75-inch intake and 1.50-inch exhaust valves, the design of this head’s heart-shaped quench-style combustion chamber makes it a good choice for mild to moderate performance. An engine with these heads in stock form will outperform an engine with stock X or J castings simply due to the improved combustion chamber design. Additionally, these heads have hardened valve seats, which make them compatible with unleaded fuel. The swirl port heads were utilized through 1991 (302 casting) and 1992 (308 casting) and respond well to port and bowl work, offering better power potential than all of the earlier small-block heads. Another nice feature of these heads is they utilize valvetrain and intake manifolds common to early small-blocks, so parts are readily available. Simply bolt these heads to your small-block and enjoy the extra power they provide.
dartfreak75
Restore it, Dont part it!
That is confusing that article said that 318 heads with 1.78 valves are not swirl port heads !?!
Interesting that they spent $1500-2000 for a 26 hp increase By changing cam, springs, intake, carb, and headers. It looks like the ported 302's made a big improvement over the 360 heads. Sure there was a good sized cam, intake, carb and headers. I have a set of 302's and a set of 920's. The 920's look like they are ready to go (I haven't taken them apart to check them) If I add them to the teen in my Swinger I will probably end up with static compression around 9.5/1. (just guessing) A LD4B, 600 Edelbrock, 340 exhaust and new 2 1/2" duals should work pretty good. May be a small cam too. If I go with a moderate cam I will probably use the 302's with 1.88/1.60 valves and some mild porting. I would probably need a converter to make it work and maybe even a 3:55 gear or so.
dartfreak75
Restore it, Dont part it!
That is some crazy results 145 hp gain from stock. I would to see that same test with different cams. I wonder if a shorter duration would change the results?
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