A Lot of holes there. Maybe that was after Turbo? Still a lot of HP for a small motor. What RPM would you be turning? I am always skeptical myself, and never up for forced induction.
Rebuilt 302 casting heads available through Rockauto
- Thread starter toolmanmike
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A Lot of holes there. Maybe that was after Turbo? Still a lot of HP for a small motor. What RPM would you be turning? I am always skeptical myself, and never up for forced induction.
greymouser7
Vagrant Vagabond “Veni Vidi Vici”
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I have some 675’s would you compete with those?
They came milled .040”
I have been polishing on one of them
a 273 would be perfect for forced induction. Everybody including the car manufacturers turbo or supercharge small cube engines. The thick bores and the steel cranks can make for a strong base. I don't know about pressure cookers as to whether they require big flowing heads or whether the pressure from the supercharger doesn't care. That is really for another thread.
I built a replacement 318 for my 91 d150 so I could swap it out on a weekend, the truck ran great but smoked sometimes. The engine I used was out of an 85 fury cop car, it had 360 heads and a Quadra jet carb. That motor was a total dog until I had the original heads redone and put them back on. Ran great then. Mine weren’t the 302, they were 714 or something with closed heart shape chambers and small ports. With the tbi and the gramma gear 4 speed it ran great. Outran my bosses new v10 truck, he was pissed.
I just chatted with a friend that is a expert about turbos. He simply explained if you trying to keep it in the stock rpm range, don't port the heads, If you are going for maximum horsepower/rpm then they need to be ported.
To me, forced induction is just another system to maintain. It is a means to add air flow to make more power. I know that is a huge simplification, but that is how I look at it. I love all classic Mopar engines from the 170 /6 to a 440. From the 50's to the 70's. If someone wanted to hot rod anything, I was up for it when I was younger. I've even seriously souped up a Ford 170 special for an early 60's Falcon and loved the end product. I'm just not interested in an extra system. Any classic Mopar engine can be made to perform well enough for me. I love driving "A" Bodies cross country, all day long, my whole life. Mostly with 273's. That is what Mopars excel at.
nm9stheham
Well-Known Member
That seems strange..... you can blow up about any engine by upping the boost enough and never touch a port LOL. Since the turbo impeller is a huge exhaust restriction and has a specific map, then it would have to be a pretty extreme setup to think of porting for most car engines. I ran 1.75 HP per ci on my 2.6L Starion engine and that was with just 14-15 psi boost... serious, but no where near an extreme amount of boost. Never touched a port.
Does this friend deal with truck turbos? If so, that is not generically applicable advice. they seem to have some pretty restrictive parts to start with.
Truck, tractor Pull truck, pull tractor and some high performance street. Plaything is one of their 2 wheel drive pull trucks.
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In my opinion...absolutely nothing.
When I was in college in Colorado, my Barracuda was my daily driver, had a mild 318 with some lightly home ported J heads and a small nitrous kit. It ran 13.9 at Bandimere (5800' altitude). I was sold on the 302 heads by a local "mopar guru", so I bought a set, did my same light home port and put them on my car. To my utter disbelief my car ran half a second SLOWER in the 1/4 mile (14.4 at Bandimere).
The 302's felt snappy driving around town, but the power was just not there compared to my other heads. I swapped heads back to my J's and sold those 302 pieces of crap. I would never pay for another set, unless I would building a completely stock motor with no power goals....which isn't going to happen.
Just my real world example, and opinion.
PRH
Well-Known Member
I heard the same thing.
PRH
Well-Known Member
The 302 style head has its place.
If I were putting a 273-318 together with a target of say, 300-325hp or less........then I’d be okay with using them.
That being said........ I’m probably just too lazy to go about it that way.
I’d just find a 360 short block, and then all the aftermarket heads work just great......... and I’ll end up with way more power for the same effort and $$$.
If I were putting a 273-318 together with a target of say, 300-325hp or less........then I’d be okay with using them.
That being said........ I’m probably just too lazy to go about it that way.
I’d just find a 360 short block, and then all the aftermarket heads work just great......... and I’ll end up with way more power for the same effort and $$$.
66jim
Well-Known Member
I have had experience with about a dozen Mopars over the years (Since 1974) with about a dozen 318 daily street drivers. Some where completely stock 2 barrel a few had 340 J heads
and a few with 302 heads. The J heads came on stronger top end,sluggish on the bottom end,302 heads and very strong off idle not as strong as J heads up top. The 318's I had with the 302 and 675 (still have 2) feel stronger and happier as a daily driver where you spend most time under 3000rpm and more mpg. No real A/B tests or dyno. Remember dyno is just a measurement tool above 3000rpm not seat of the pants or dragstrip.
and a few with 302 heads. The J heads came on stronger top end,sluggish on the bottom end,302 heads and very strong off idle not as strong as J heads up top. The 318's I had with the 302 and 675 (still have 2) feel stronger and happier as a daily driver where you spend most time under 3000rpm and more mpg. No real A/B tests or dyno. Remember dyno is just a measurement tool above 3000rpm not seat of the pants or dragstrip.
Well said. You need big valves and ports to work at higher rpm. 318 owners spend most of their time at 3000 rpm or below. Most mild cams torque range fall off around 3000 rpm anyway.
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