Seems like there has been a big influx of porting knowledge being displayed on the interwebs lately. From Holdener doing some basic stuff FIRST TIME EVER and picking up good numbers to David Vizard getting on youtube.
I'm using an old article from Dulcich to do these.
Couple other guys Ive found on YT are Charles Sevedio, Eric Weingartner, Tom Mews (long winded) and also Terry Grover (good listen on 1.5x speed lol).
Here's my attempt working on 2nd head exhaust first.
[video:youtube]wkoC6aqMeIQ[/video]
Last edited by Prochargedmopar; 12/05/2108:15 PM.
"Old" member Registered: Sep 2001 Lost my credentials, I'm Back!! LOL 71 Ply Satellite Procharged 73 Dodge Dart Swinger 73 Ford F-100 390/Sniper efi/back to carb 01 Town and Country Limited 08 Dodge 2500 6.7 5" Deleted 02 Mercedes C230K 19 Camry
Machine shop honed block, installed core plugs, ground crank 10/10, repaired/welded worn thrust surface on crank also. Stock pistons flipped (even though it's been scientifically proven not to do squat) with new ring gap opened up. 218/218 summit cam bout .480 lift with 1.6 magnum rockers. Magnum heads home brew porting under way. Can't decide yet between Edelbrock LD4B dual plane or Holley street dominator single plane. Not sure which one I want to give up. LOL 72 904 with shift kit and tci 3000 stall convertor. dual 2" exhaust/stock manifolds. Ooooof.
All going into 72 Satellite.
Last edited by Prochargedmopar; 12/05/2110:20 PM.
"Old" member Registered: Sep 2001 Lost my credentials, I'm Back!! LOL 71 Ply Satellite Procharged 73 Dodge Dart Swinger 73 Ford F-100 390/Sniper efi/back to carb 01 Town and Country Limited 08 Dodge 2500 6.7 5" Deleted 02 Mercedes C230K 19 Camry
I own the original 1996 Mopar Performance clear plastic “porting templates” for the 1992-2001 5.2/5.9 V8 cylinder heads and would be willing to attempt to take photos of them laying against engineering grid paper, although my fuzzy memory is that already exists here somewhere in the archives of Moparts.
I worries me a little in the video that you keep using the word “smooth.”
Air moving through the Magnum intake ports is NOTHING like water flowing through pipes.
Swirl and Tumble intermixed with slinky like waves moving both forward and back is a more productive way to try to imagine what needs improving.
The “soapdish” in the Magnum piston crown is all about creating “tumble” and the flats outside the soapdish are all about creating a violent “squish” that boost a swirl that started in the intake runner and was boosted more in the intake cylinder port.
The Magnum is a “fast burn” heart shaped head that gains power by needing less ignition advance. Making flow “smooth” will reduce the fast burn power advantage, and can create a cylinder head that flows more but produces less hp at high rpm.
The flow out the exhaust port is nothing like water in a pipe, a better picture to hold in your mind’s eye is the gas coming out a machine 9¥N.
Early Viper V12 engines used Magnum 5.9 V8 pistons for cost reasons according to Willem Weertman’s book, which means that the ports and combustion chamber shape of the early V12 cylinder heads provide clues to getting high rpm performance gains when you modify the “truck engine” stock ports.
Re: Porting some Magnums for Sons 318LA
[Re: 360view]
#2992474 12/06/2109:35 AM12/06/2109:35 AM
A dozen years or so ago, I built a similar engine for my son's Scamp. Used the templates to port the Magnums. That engine ran great. First outings at the track netted 8.10s. I always wished I had put a little more converter and a little more cam in it. Mid to upper 7s would have been easy. And the thing idled and drove like a stock 318. What a great combo. Good luck with yours.
P.S. Get the templates. Don't shoot blind. Improvements are not necessarily intuitive.
Master, again and still
Re: Porting some Magnums for Sons 318LA
[Re: DaveRS23]
#2992505 12/06/2110:48 AM12/06/2110:48 AM
The process is called porting but what us DIYers are really doing is removing casting lumps, chunks, burrs and flash. It is good to contour the valve guides (Not remove them as some back in the day advised.) No "hogging out" just making the port and bowl what the factory would have liked to have done but were refrained by cost. Many will say to just buy some new aluminum heads. If one has good used heads with healthy guides and seats than porting yourself is the best way for great power and on a true working mans budget. Plus its true hot rodding.
Keep old mopars alive.
Re: Porting some Magnums for Sons 318LA
[Re: 2boltmain]
#2992511 12/06/2111:11 AM12/06/2111:11 AM
Critically analyzing our modification plan for the intake port, we started at the bowl area just under the valves, and we could see there were areas where large flow gains could be had. Blending the bowl and opening up the valve job to a spec closer to the full potential of the valve size will usually result in large flow gains. However, gains in these areas on the Magnum heads were modest. While there seemed to be plenty of flow left on the table in these areas, the bowls are proportionately large in comparison to the tight port runners. In contrast, opening up the pushrod constriction unlocked a substantial amount of flow, as did reworking the obstruction at the guide boss. It seems the Magnum's large bowl and small runner work together in kind of a happy harmony, with a balance of flow potential that requires mods at each end of the bowl and runner to significantly impact the overall port flow.
"Old" member Registered: Sep 2001 Lost my credentials, I'm Back!! LOL 71 Ply Satellite Procharged 73 Dodge Dart Swinger 73 Ford F-100 390/Sniper efi/back to carb 01 Town and Country Limited 08 Dodge 2500 6.7 5" Deleted 02 Mercedes C230K 19 Camry
back in the 70's, when changing 318's to dual exhaust using the stock manifolds, we blew the pipes to 2 1/2" od as quick as we could for the full exhaust system, at the muffler shop. made a noticeable difference in the was the car ran, plus better gas mileage ! [provided you kept your foot behaved]
Re: Porting some Magnums for Sons 318LA
[Re: moparx]
#2992556 12/06/2101:14 PM12/06/2101:14 PM
I enjoy these types of builds and related posts. This is what hot rodding is all about-making the most of what you have. Looking forward to your impressions of the final results.
Re: Porting some Magnums for Sons 318LA
[Re: mgoblue9798]
#2992645 12/06/2105:56 PM12/06/2105:56 PM
I realize it is too late but the effort and money in stock heads is exhausting when you can just get a set of Box Stock Eddy's and do a little clean up work to them
Re: Porting some Magnums for Sons 318LA
[Re: TheOtherDodge]
#2992657 12/06/2107:02 PM12/06/2107:02 PM
I realize it is too late but the effort and money in stock heads is exhausting when you can just get a set of Box Stock Eddy's and do a little clean up work to them
Haha,
I done spent way to much money on this boys FREE to him classic vehicles via early inheritance. (19yo kid, 73 Ford, 72 Satellite, LOTS of PARTS)
I'm retired and having fun on a "when I get the time" project I've been dreaming about doing since the early 2000s.
Yeah, I got a set of fully ported (300/209@6) Chinese Side Winders done up by Larry Smith for my project that have been sitting since 2017. Billet 78/75 turbo in hand also.
Once I get this little 318 out of the way, it's GO time.
"Old" member Registered: Sep 2001 Lost my credentials, I'm Back!! LOL 71 Ply Satellite Procharged 73 Dodge Dart Swinger 73 Ford F-100 390/Sniper efi/back to carb 01 Town and Country Limited 08 Dodge 2500 6.7 5" Deleted 02 Mercedes C230K 19 Camry
Critically analyzing our modification plan for the intake port, we started at the bowl area just under the valves, and we could see there were areas where large flow gains could be had. Blending the bowl and opening up the valve job to a spec closer to the full potential of the valve size will usually result in large flow gains. However, gains in these areas on the Magnum heads were modest. While there seemed to be plenty of flow left on the table in these areas, the bowls are proportionately large in comparison to the tight port runners. In contrast, opening up the pushrod constriction unlocked a substantial amount of flow, as did reworking the obstruction at the guide boss. It seems the Magnum's large bowl and small runner work together in kind of a happy harmony, with a balance of flow potential that requires mods at each end of the bowl and runner to significantly impact the overall port flow.
How on earth did you come to the conclusion that home porting the Magnums were a waste of time?
Dulcich says "Even with a basic effort, the exhaust flow improvement was dramatic, gaining a staggering 41percent." He goes on to say "The only question that remains is whether it was worth it. For the level of work involved and the power potential gained, we'd have to answer that with a resounding yes. Thirty-four cfm of intake flow has the potential to add a solid 50-60 hp to a combination built to take advantage of the additional flow, and we'd expect a nice extended power band with the increase in port cross-sectional area and substantial exhaust flow. With gains like that up for grabs, I'd spend a Saturday making cast-iron chips."
Are we reading the same article?
Cast iron heads take a good amount of time to port. I think that the instructions that accompanied the templates said something like 12 hours. And you will taste cast iron for days after that. But my experience mirrors Dulcich's. Definitely worth it!
Master, again and still
Re: Porting some Magnums for Sons 318LA
[Re: DaveRS23]
#2992749 12/06/2111:12 PM12/06/2111:12 PM
Critically analyzing our modification plan for the intake port, we started at the bowl area just under the valves, and we could see there were areas where large flow gains could be had. Blending the bowl and opening up the valve job to a spec closer to the full potential of the valve size will usually result in large flow gains. However, gains in these areas on the Magnum heads were modest. While there seemed to be plenty of flow left on the table in these areas, the bowls are proportionately large in comparison to the tight port runners. In contrast, opening up the pushrod constriction unlocked a substantial amount of flow, as did reworking the obstruction at the guide boss. It seems the Magnum's large bowl and small runner work together in kind of a happy harmony, with a balance of flow potential that requires mods at each end of the bowl and runner to significantly impact the overall port flow.
How on earth did you come to the conclusion that home porting the Magnums were a waste of time?
Dulcich says "Even with a basic effort, the exhaust flow improvement was dramatic, gaining a staggering 41percent." He goes on to say "The only question that remains is whether it was worth it. For the level of work involved and the power potential gained, we'd have to answer that with a resounding yes. Thirty-four cfm of intake flow has the potential to add a solid 50-60 hp to a combination built to take advantage of the additional flow, and we'd expect a nice extended power band with the increase in port cross-sectional area and substantial exhaust flow. With gains like that up for grabs, I'd spend a Saturday making cast-iron chips."
Are we reading the same article?
Cast iron heads take a good amount of time to port. I think that the instructions that accompanied the templates said something like 12 hours. And you will taste cast iron for days after that. But my experience mirrors Dulcich's. Definitely worth it!
I think you quoted the wrong guy. LOL
I stated using the porting templates was a waste of time. Dulcich said that in another article on Big Block head porting me thinks, maybe even said that about the SB templates too.
"Old" member Registered: Sep 2001 Lost my credentials, I'm Back!! LOL 71 Ply Satellite Procharged 73 Dodge Dart Swinger 73 Ford F-100 390/Sniper efi/back to carb 01 Town and Country Limited 08 Dodge 2500 6.7 5" Deleted 02 Mercedes C230K 19 Camry