Let's Build a 416 with Cast Iron Heads and Manifolds

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Insert 340 block for the 360 and drop the compression down from 12.2 to pump gas friendly and in a well sorted car you are probably high 11’s. Go forged crank. Mine is a 78 360 block bored to .040. With Icon forged flat top pistons .010 in the hole. Scat h beam rods and Scat 4” cast crank. The heads are x heads ported by Dwayne Porter of Porter Racing Heads. Flow about 274 cfm intake. The cam is an Engle flat tappet intake .557 lift 245 degs at .050 lift. Exh is .551 lift with 261 degs at .050 lift. 112 degs lobe seperation. Intake is stock 68-69 340 manifold with the divider cut down and smoothed out a bit. Stock hipo 340 exh manifolds. Pypes race pro mufflers. Eddy 800 cfm AVS thunder series. Two fuel pumps. A big Carter mechanical and a Holley red pump back at the tank with Holley hydra mat inside. Mallory billet distributor and MSD 6al. There is room for improvement in the above, but that is what I’m running.

The not so street friendly bits, but they don’t bother me. 904 trans with Cope RMVB with a PTC 9.5 “ converter. 4:10 rear gear in an 8 3/4”. TTI 2.5” exhaust. Slant 6 front torsion bars with QA1 R’s on the front and 1” over arched leafs on the rear with QA-1 double adjustable rear shocks. Car is original 68 Barracuda 340-s Fastback, weighs 3353 lbs with me in it. Tires are f70-14 polyglas redlines. Best run is 1.60 60’ 11.393. Best mph is 117.22 Shifting at 6500 rpm.”
 
furrystump said:
Insert 340 block for the 360 and drop the compression down from 12.2 to pump gas friendly and in a well sorted car you are probably high 11’s. Go forged crank. Mine is a 78 360 block bored to .040. With Icon forged flat top pistons .010 in the hole. Scat h beam rods and Scat 4” cast crank. The heads are x heads ported by Dwayne Porter of Porter Racing Heads. Flow about 274 cfm intake. The cam is an Engle flat tappet intake .557 lift 245 degs at .050 lift. Exh is .551 lift with 261 degs at .050 lift. 112 degs lobe seperation. Intake is stock 68-69 340 manifold with the divider cut down and smoothed out a bit. Stock hipo 340 exh manifolds. Pypes race pro mufflers. Eddy 800 cfm AVS thunder series. Two fuel pumps. A big Carter mechanical and a Holley red pump back at the tank with Holley hydra mat inside. Mallory billet distributor and MSD 6al. There is room for improvement in the above, but that is what I’m running.

The not so street friendly bits, but they don’t bother me. 904 trans with Cope RMVB with a PTC 9.5 “ converter. 4:10 rear gear in an 8 3/4”. TTI 2.5” exhaust. Slant 6 front torsion bars with QA1 R’s on the front and 1” over arched leafs on the rear with QA-1 double adjustable rear shocks. Car is original 68 Barracuda 340-s Fastback, weighs 3353 lbs with me in it. Tires are f70-14 polyglas redlines. Best run is 1.60 60’ 11.393. Best mph is 117.22 Shifting at 6500 rpm.”
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game set match
 
My 360 with a stock crank, flat top pistons and ported J heads, .510 lift cam went 10.60s i don't see the need to do a stroker to be in the 12s, just my opinion.
 
ValiantRacing said:
My 360 with a stock crank, flat top pistons and ported J heads, .510 lift cam went 10.60s i don't see the need to do a stroker to be in the 12s, just my opinion.
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you running manifolds?
gear ratio?
weight?
 
Guys let’s stay on track. I’m not building a 360, not running headers and not running 4.56 gears. The build is a 416 or 435, J heads, four speed with 3.55 gearing. Carry on.
 
BrianT said:
Guys let’s stay on track. I’m not building a 360, not running headers and not running 4.56 gears. The build is a 416 or 435, J heads, four speed with 3.55 gearing. Carry on.
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ValiantRacing said:
No manifolds, running headers, 4.56 gears and about 3100.
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so drop the manifolds on 3.55s and 3500 lbs you would run what? low 12s
cubes make it a nice street car less gear required still run 11s
something to be said for sucking the paint of cars with headers and gears while looking stock and street friendly manners which iam pretty sure what his build is about
 
a-bodyguy said:
something to be said for sucking the paint off cars with headers and gears while looking stock and street friendly manners which I am pretty sure what his build is about
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I may or may not have a certain car in mind. :elmer:
 
In an interesting turn, I am working on a deal with Brian at IMM on some W2 heads. So now the build becomes 435 W2 heads solid roller cam. Still plan on running through the manifolds for the time being.
 
I can see where this is headered, I mean headed.. You’re one killer deal away from pushing thoughts of running cast iron manifolds over the cliff.

:rofl:
 
But but butt you said absolutely positively that you were dead set on running a certain stock head and to keep the post on point. Lol. There goes a four page post
 
What possible gain do you think you would get switching to w2 heads and still running through exhaust manifolds? If your goal is still through exhaust manifolds running 12's you are adding a whole bunch of money and work for absolutely nothing.
 
Wow, this thread took an ugly turn fast? I don’t know what I’m supposed to grow up or man up about? The whole thread is about building a stroker engine using iron heads and cast-iron manifolds. That part hasn’t changed?
 
Your car and your dollar, do as you please and let the naysayers get stuffed. Where I draw the line is that brakes and steering are up to the task.
What are the valve sizes and what could be fit?
I take it idle quality is not a Cadillac smooth quality importance.
 
Your car and your dollar, do as you please and let the naysayers get stuffed. Where I draw the line is that brakes and steering are up to the task.
What are the valve sizes and what could be fit?
I take it idle quality is not a Cadillac smooth quality importance.
 
You can widen the LSA to reduce overlap. With 52CID/cylinder and a 2.02 intake valve, a 100° LSA is indicated as optimal for a starting point. It is better for overall performance to keep the recommended LSA and reduce valve event timing a slight amount to get the overlap reduced. The engine will run through its power band better.
 
12many said:
If the heads highest flow is at a certain lift and you only cam it with a lift in that range than how much time is it really open at that lift? Not much. I’ve always understood (I know I’ve read that here and over on Speed-Talk among other sources) that you want more lift (to a point) so the valve spends theoretically more time in that usable lift range as it reaches a higher lift where it’s not really open there very long anyway. Maybe the flow bench experts can clarify or expound on this?

Edit: yup, I lnew I’ve read about this elsewhere. (again, more lift “to a point”)

One example: lift vs. peak head flow - Don Terrill’s Speed-Talk
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Port flow and at what lift does it go flat is the determining factor for valve lift. Kind of wasting expensive heads that will flow high numbers up to 0.700" lift. Conversely using a cam that provides that lift with heads that peak at about 0.500"lift is pointless. If the heads peak at 0.500" valve lift, then a cam that provides a max lift of 0.530" will allow a few degrees more time at that flow rate. Considering that higher lift requires stronger springs to maintain valve control, and those springs create higher friction in the engine. A few thousandths will not create exponentially high loading.
 
rumblefish360 said:
Porting of the intake manifold, exhaust manifolds and heads to their maximum abilities is the only route. OEM heads can go pretty far. I’ve seen 275 from the letter heads. This will be reduced significantly with the iron manifolds. Once you have the intake and heads ported, have them flow tested together to see not only how well they flow together, it’s how much and where the best air flow happens. Only from there can you even consider a camshaft.

Select your intake and exhaust manifolds wisely.
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Manifolds are part of the exhaust, so restrictive ports or manifolds equate to about the same. To overcome that a bit the exhaust seats can be cut to 40° which aids the low lift flow. This aids blowdown to get the scavenge cycle going strong.
 
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