stixx
Well-Known Member
^^^^^^^^ I was just about to suggest that. Good that I kept my mouth shut. 
Junkyard 5.9L Magnum + Edelbrock LA heads build
- Thread starter MopaR&D
- Start date
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nm9stheham
Well-Known Member
Careful work with a hand drill will do it. And brake line can be used.... plenty of fitting from inverted flare to NPT. I'd put a 1-2" loop in brake line to give some expansion room.
Yes, those 45 degree fitting look problematic. but the whole deal looks nicely done!
Do you have any provision for adjusting a restriction to control the flow? Perhaps a straight tapped holed behind the angle fitting in the head, to put a changeable restriction? I am imagining a Holley jet for flow control! (Brass in aluminum is not a good idea unless you can keep all water away... which seems the case here.)
The drilled bolt seems to be a good restriction. I don’t know how small you would want the hole. Toluene56 & in the link, the fella that did this used a 1/16 bit to drill the bolt.
Why would the 90* fittings be a problem?
Why would the 90* fittings be a problem?
I have swapped one side to a 90 for more clearance. As far as restriction I very carefully drilled the connecting hole on the bolt fairly small. Just enough for the tip to break through, if this isn't enough I was going to set up some kind of orifice setup kinda like nitrous solenoids. We'll see how it goes, it oils good with a drill at the moment. But we'll see how the oil control is when it's running hot.
Everything fits.. I swapped the passenger side to a 90* fitting and kept the 45 on the driver side. Plenty of room.
View attachment 1715268059
View attachment 1715268059
nm9stheham
Well-Known Member
Just don't do any Dukes of Hazzard jumps and it will be fine LOL
Beautiful work. Now replace that plastic line with a copper one.
MopaR&D
Nerd Member
Fantastic! I'll probably run 90-degree fittings on both heads which will hopefully be a tad smaller since I'm using 1/8" NPT, I haven't started that aspect of the build yet though. Right now I'm working on getting the pushrod holes in the heads clearanced (busted my small Dremel the other night from being dumb, had to buy a new one). I also found on mocking up the valvetrain the pushrods are incredibly long for this combo, as in the valves were being held open even when the cam lobes were on the base circle! I couldn't even turn the engine over completely before the valves hit one of the pistons. And I was using the shorter stock Magnum pushrods not the longer LA ones I also have.
SOOO looks like I'll be buying head gaskets next so I can get an accurate measurement of what length pushrods I need. Once the valvetrain is squared away and won't destroy itself I'll get onto the rocker oiling.
SOOO looks like I'll be buying head gaskets next so I can get an accurate measurement of what length pushrods I need. Once the valvetrain is squared away and won't destroy itself I'll get onto the rocker oiling.
MopaR&D
Nerd Member
Alrighty, just placed my Summit order for the Cometic head gaskets, all the lines and correct (90*) fittings for my oiling setup (thanks again @Toluene56 !!) and some other random parts... plus a cool vintage 1972-style faux-leather Mopar Parts & Service hat for 30% off lol. Should arrive later this week I usually get stuff from Summit in 2-3 business days.
Bitchin' ... I know it works now, got the new engine running and didn't get the valve covers seated properly... oil.. everywhere.
MopaR&D
Nerd Member
Nice good to know, do you have a thread of your build?
MopaR&D
Nerd Member
We're getting closer! I painted my heads today and my head gaskets and oiling parts came in the mail... only "big" stuff left to purchase is a crank damper and a new radiator. Hopefully over the next few days i'll get the heads on and torqued down then put together the external oiling system, also need to get those two end rocker bolts drilled out... probably just gonna take them to a machine shop.
MopaR&D
Nerd Member
Not a whole lot of progress but I did CC a couple of the combustion chambers to get an idea of my static CR... turns out they're about 63cc which gives an SCR of only 9:1 (8.95:1 to be exact). Not too thrilled about that and I'm curious how it will run in the lower RPM range with that kind of SCR, according to the Wallace Racing calculator that puts my dynamic compression at around 7.3:1 taking into account the lower air density at 5000 feet above sea level.
I'm glad I had the cam custom-ground with no more duration/overlap than it has and hopefully my 2600-RPM stall converter will put the RPMs high enough at launch for it to not be a dog, I did explain to Jim at Racer Brown that I am at high altitude and he took that into consideration. I probably also need to swap out my 2.94 rear gears for 3.55s even more now with this knowledge.
I'm glad I had the cam custom-ground with no more duration/overlap than it has and hopefully my 2600-RPM stall converter will put the RPMs high enough at launch for it to not be a dog, I did explain to Jim at Racer Brown that I am at high altitude and he took that into consideration. I probably also need to swap out my 2.94 rear gears for 3.55s even more now with this knowledge.
nm9stheham
Well-Known Member
I'm trying to reproduce your numbers.... I forget... Is this still the stock block and pistons? Pistons around .090" in the hole?
MopaR&D
Nerd Member
Stock 5.9 Magnum short block, pistons are .050" down at TDC and have a 14cc dish. Also using Cometic MLS head gaskets with .027" compressed thickness and 4.04" bore diameter (for the gaskets, engine is still stock bore at 4.00")
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Squeeze is squeeze. The thermo efficiency of the aluminum will not be a draw back. At your altitude, A 9.0-1 ratio is good for 87 octane. If the cam is large-ish, it will just feel a little soft on the bottom end.
MopaR&D
Nerd Member
Cool, yeah I'm not too concerned about the heat transfer with the aluminum heads, seems like that's finally been generally accepted as an old wives' tale. Maybe at very low RPM there might be a small difference but each cycle happens so quickly there's barely enough time for the heat to transfer from the combustion gases into the head before it gets exhausted and a fresh mixture is pulled in.
Cam is 222/226* duration at .050" (274/278* advertised at .008" lift) with 110* LSA and 106* ICL with .548/.544" lift with 1.5 ratio rockers.
Honestly after blowing up my last engine due to constant pinging from too high cylinder pressure (much too small a cam for 10.5:1 SCR) it'll be relieving to not have to worry about that. Just fill 'er up and go!
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nm9stheham
Well-Known Member
It is a matter of the relative temps at the start of combustion, the temps during combustion and the temps at the end of the power stroke. So if the absolute temps vary up or down, but the start, middle and end temps stay relatively the same, the pressures, torque and etc. will be the same.
FWIW: With your dimensional numbers, I am getting 8.9 SCR and 7.2 DCR at sea level (which is the difference I would expect with a cam with advertised intake duration of 274), with 6.2 effective DCR at 5000'. So, yes on the rear gears.....
FWIW: With your dimensional numbers, I am getting 8.9 SCR and 7.2 DCR at sea level (which is the difference I would expect with a cam with advertised intake duration of 274), with 6.2 effective DCR at 5000'. So, yes on the rear gears.....
MopaR&D
Nerd Member
OK sounds about right, I didn't understand the "boost compression" on the Wallace Racing calculator but I realized it does mean corrected for altitude so I got the same numbers you did. BUT let's try something else... so a bone-stock 5.9L Magnum is rated at 8.8 SCR and with a stock cam having 62 ABDC intake closing (according to online sources), DCR at 5000' elevation is 6.19. And I know for a fact that even at this altitude a stock 5.9 Magnum has boatloads of bottom-end torque right off idle. SOO if my DCR is essentially the same as a bone-stock 5.9 truck engine I'm thinking the low-end torque should be adequate.
Shoot, maybe that's what Jim was shooting for with my cam? Trying to get the DCR the same as a stock engine? Smart, if that's true...
I’d say probably so and with use in conjunction of the rear gears and tire size you are running. This is why cam and torque converter companies want ALL the info they can get.
nm9stheham
Well-Known Member
Or maybe said as 'no lower than stock DCR (and torque), with a gob more lift'. Higher lift to duration ratio tends to be good for street use; several sources for that type of grind. So if you are happy with that torque level and that is the right stock cam ICA number then you will be a happy guy.
62 ABDC for the stock cam ICA seems a bit long however.... but I do see that number here: 5.9L Valve Timing Specs
Is this where you got that number? I see the earlier cams are listed at 80 ABDC.... makes me wonder at what lift value these stock advertised numbers were measured.... I see from your cam card that Racer Brown did them at .008" lift.
So maybe the present rear gear is good enough to be happy with? Better for mileage..... unless it ends up being at or below stall speed a lot of the time.
MopaR&D
Nerd Member
Yes that is where I got those numbers. I ran this same converter before with my old 7 1/4" rear with 2.76 gears and the slippage wasn't too bad, I did add a fairly large trans cooler and cast deep trans pan though for peace-of-mind. We'll see how it runs first but I already have a 489 case 3rd member I just need to buy a 3.55 ring and pinion and rebuild and swap my current sure-grip unit.
I always love me a deep pan & cooler!
MopaR&D
Nerd Member
FINALLY the heads are on... I took my time making sure the block deck surfaces were squeaky-clean and smooth for the Cometics to seal and also the threads were clean so the studs would screw in easily. Got some ARP lube for the nuts and looked up the torque spec on ARP's website, 110 ft-lbs.
Also mocked up the intake, i'm a bit worried about it not sitting low enough once the gaskets are on but I need to get said gaskets first to be sure.
Also mocked up the intake, i'm a bit worried about it not sitting low enough once the gaskets are on but I need to get said gaskets first to be sure.
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