So was just curious peoples thoughts on this build. I'm sorts new to building my own engine as well. I have a 96 magnum, gonna send it off to get cleaned and have the cylinders honed. Crank will be stoked with KB167 pistons +5cc with .027 head gaskets, and a .509 lift cam 108 or 110 separation. And heads will be stock with light port smoothing and ill gasket match. High rise air gap intake and 650-700cfm carb. This is just to get the car driving so I can save for a 5.9 stroker kit. Thoughts? I'm hoping this will bump the CR up a bit...
Thought on a magnum build
- Thread starter Janke1010
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junkyardhero
Well-Known Member
KB167's aren't for magnum (well, they can be but that's a whole nuther ball o' wax) so you'll need to choose a different piston.
i don't understand the phrase: crank will be stoked with...
personally, i'd say if you're saving up for a stroker kit just run the stock pistons. do rings/bearing & cam bearings and a hone, clean everything up and ship it.
any particular reason for the 509 cam?
i don't understand the phrase: crank will be stoked with...
personally, i'd say if you're saving up for a stroker kit just run the stock pistons. do rings/bearing & cam bearings and a hone, clean everything up and ship it.
any particular reason for the 509 cam?
Don't have any cylinder work done without the machine shop having the pistons so they can hone to the actual piston clearnce spec.
Why wouldn't they work for a magnum?
They
Why wouldn't kb167s work? I picked em up fairly cheap, they are advertised for a 5.2 magnum? Same bore and stroke measurements as well? I meant to type crank is stock lol
junkyardhero
Well-Known Member
to my knowledge, the KB167 is not made for magnum motors. magnum and LA motors have different widths on the little end of the rod, and thus the piston pin boss is narrower or wider to accommodate.
it's not clear: are you building a 5.2 now or are you building a 5.9?
it's not clear: are you building a 5.2 now or are you building a 5.9?
I'm building the 5.2 now, well I sure hope that's not the case uempistons.com shows the product to fit a 5.2 magnum and can be either pressed or floating, not saying your wrong just stating what the website says.
They are a +5 which I know is a cavity instead of dishing up, but the compression height on these are like 1.81 as well
I would just Put a good intake and carburetor and decent set of headers on the Magnum and go with it.
The Summit site says the KB167 fits both Magnum and LA engines and we know that to be untrue, since, as JYH said, the small end of the rods from LA to Magnum are different widths. Also, the Magnum and LA blocks have different deck heights as well. Probably best to call United Engine and Machine and get to the bottom of it.
The Summit site says the KB167 fits both Magnum and LA engines and we know that to be untrue, since, as JYH said, the small end of the rods from LA to Magnum are different widths. Also, the Magnum and LA blocks have different deck heights as well. Probably best to call United Engine and Machine and get to the bottom of it.
junkyardhero
Well-Known Member
pressed or floating makes no matter. it's the width of the rods/pin boss that's going to be of issue.
you have the pistons in hand? measure them and find out.
you can't always trust what's listed, sellers make mistakes all the time. trust but verify, always.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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IMO,
The DC509 is not for a 5.2, especially not for an automatic car, unless your pockets are deep.
I ran that cam (the 292/108) in my 367-4speed, at 11.3 Scr, and it was still soft on the bottom. My 509 measured 248/[email protected] You need a lot of Scr to make that work. But worse is that the Power is up around 5400, and you're 1>2 shift will probably like to be around 5800 or more which means, you're gonna have to do some oiling mods to help keep rod-bearings in her.
With an auto, you're gonna need a minimum 3.91 rear gear and a much higher than stock stall. and Your trans is gonna need to beefed up, and the Governor changed, and if you have 7260 U-joints, you better have a driveshaft loop, and you better have the biggest tires on the back that fit into the tubs, with the springs moved over.
and, On the front, yur gonna need the widest tires you can fit, and disc brakes, and make doggone sure that the suspension and steering are up to the task, and Have fun with your cooling system.
Why all this?
well ....... when you nail that gas-pedal, with that cam, as soon as she gets up on the cam, things tend to happen in a hurry, and top of Second gear is 85mph with those 3.91s, about 4/5 seconds from 45, and if yur in a 45mph zone, yur gonna have to use both feet on the brake pedal to get slowed back down. And that's assuming the car goes straight in both directions.
If you have a small-tub car, forget about the 509 cam. about the biggest tire you can put on the back is a 255, until you move the springs, and then maybe 275s maybe. My 367 annihilated those in one summer.
IMO, leave the stock cam in her, but put her in at "straight up", or up to 4* advanced, which means you can put just about any old dualplane on it., and you don't need headers anymore, which with the 509 you would have to have, even just to make it worthwhile to run that cam; with logs, you forfeit the 76* of overlap....... If you give up that overlap, you might as well put a cam in there ~3 sizes smaller. ........... which I highly recommend anyway, lol.
IMO
If you just gotta have a cam, then;
after you get your Exact Scr worked out, Plug a high-energy 224/230 @108 to 106LSA, into the Wallace Calculator, and see how the cylinder pressure might come in. I mean it might be too high. and you don't want to find that out after you already bought the thing.
The DC509 is not for a 5.2, especially not for an automatic car, unless your pockets are deep.
I ran that cam (the 292/108) in my 367-4speed, at 11.3 Scr, and it was still soft on the bottom. My 509 measured 248/[email protected] You need a lot of Scr to make that work. But worse is that the Power is up around 5400, and you're 1>2 shift will probably like to be around 5800 or more which means, you're gonna have to do some oiling mods to help keep rod-bearings in her.
With an auto, you're gonna need a minimum 3.91 rear gear and a much higher than stock stall. and Your trans is gonna need to beefed up, and the Governor changed, and if you have 7260 U-joints, you better have a driveshaft loop, and you better have the biggest tires on the back that fit into the tubs, with the springs moved over.
and, On the front, yur gonna need the widest tires you can fit, and disc brakes, and make doggone sure that the suspension and steering are up to the task, and Have fun with your cooling system.
Why all this?
well ....... when you nail that gas-pedal, with that cam, as soon as she gets up on the cam, things tend to happen in a hurry, and top of Second gear is 85mph with those 3.91s, about 4/5 seconds from 45, and if yur in a 45mph zone, yur gonna have to use both feet on the brake pedal to get slowed back down. And that's assuming the car goes straight in both directions.
If you have a small-tub car, forget about the 509 cam. about the biggest tire you can put on the back is a 255, until you move the springs, and then maybe 275s maybe. My 367 annihilated those in one summer.
IMO, leave the stock cam in her, but put her in at "straight up", or up to 4* advanced, which means you can put just about any old dualplane on it., and you don't need headers anymore, which with the 509 you would have to have, even just to make it worthwhile to run that cam; with logs, you forfeit the 76* of overlap....... If you give up that overlap, you might as well put a cam in there ~3 sizes smaller. ........... which I highly recommend anyway, lol.
IMO
If you just gotta have a cam, then;
after you get your Exact Scr worked out, Plug a high-energy 224/230 @108 to 106LSA, into the Wallace Calculator, and see how the cylinder pressure might come in. I mean it might be too high. and you don't want to find that out after you already bought the thing.
Last edited:
junkyardhero
Well-Known Member
aftermarket pistons come in a variety of compression heights-- and ring packs! so just because it's close to stock magnum, again, doesn't mean that it's correct.
anyway, the *one* of the things i'd be trying to take advantage of is the thinner ring pack on magnum pistons...
anyway, to circle back... if you're saving for a 5.9 stroker i'd be trying to put in the *bare* minimum. as RRR said, snap on a manifold, carb and some headers and just roll with the stock bottom end freshened up.
and re-think that 509 cam
All good points!! I appreciate it, that's why I enjoy these forums, I may just stick with the whiplash cam hughes offers with the beefier springs lol
Yea the previous guy mentioned the 509 cam, I think I may just go with Hughes whiplash cam for now, I wouldn't mind running stock components, but at the rate I'm able to save it'd be a few years lol so I wanna be able to enjoy it a bit, ill start to take apart the engine and get the measurements needed for the wrist pins. If I can get these pistons to work and with the whiplash cam I believe those two would work pretty nicely, and of course gotta check piston- valve clearence lol
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Those cams are made for low-compression engines.
In a 9.2 engine your pressure might get into detonation with pumpgas.
In a 9.2 engine your pressure might get into detonation with pumpgas.
I just gotta call hughes and give em my info and see what they recommend
The Whiplash cams are not immune to needing the same things as any other lumpy cam. Higher speed stall converter and higher numerical gears. They don't magically and suddenly "not need" that stuff, because they have a snappy name. It'll be a dead dog unless you match the engine, converter and rear gears.
junkyardhero
Well-Known Member
i wouldn't buy anything from hughes except for their spring/retainer kit and the cam snout extension.
if you want a cam, send yours out and have it reground. oregon cams has a bunch of great grinds and Ken is very knowledgeable and easy to work with. though you'll need new pushrods, so keep that in mind.
Yea my bad I forgot to mention itll be backed behind a 833 with 355 sure grip
remytherat
Well-Known Member
And you’ll likely need them anyways with most of the aftermarket cams.
Why mess with aftermarket pistons? I don’t get the appeal. If I was you, I would go with stock bottom end and deck the block if you want more compression, though I don’t think that’s necessary. Chinagap intake, 650-750 carb, mopar electronic ignition and a regrind about 210-220@ .050 you’ll have a decent runner.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Yeah that's exactly what I ran with the 509/108
>Hey but, I tried 4.88s which were dynomite., but first gear was over in milliseconds, not what you want in a streeter.
>Next I tried 4.30s which with the standard 2.66 gearset gave me a nice starter of 11.44; but cruising 65= 3480 was unacceptable.
>Next I installed an F-body 3.09box and installed some 3.23s to see how that 9.98 starter would work , which I really liked. But the 509 cam hated those gear-splits, and 65mph was now 1910rpm, too low for that cam.
> But the very worst thing about that cam was that the slowest speed I could drive at, with the 3.09 low and 3.55s was 4mph @550rpm; BUT, that cam was not a fan of 550rpm. So parading was OUT.
>finally I said to 'ell with that cam, tore it out and sold it to an up and coming racer. NEVER have I been sorry.
>I knew going in that, that cam would be iffy, and I really tried to like it, and if I would have had a 5-speed, I could have made it work. I just needed something like 4.10s and a .78 overdrive............ Which overdrive I would save up for and eventually get. But by that time I had a much better combo.
If you don't already have an A833, I highly recommend the Commando gearset. 3.09-1.92-1.40-1.00, she works really well with 3.55s and a cam around 223/230/110@050, even to the cam I have had now since 2004, a 230/237/110 ....... But I wouldn't buy a 110 cam again, in these sizes; maybe not any size.
If you insist on running that 292 cam, and you have NEITHER a trans Nor a Rear gear, then I highly recommend a high-stalled auto with 3.91s.
But if not married to the 292/108 then
I highly recommend something in the 222>228 range, and on a 108 or less LSA, then still the Commando box and 3.23s. But, that cam will suffer a rear gear right down to 2.76. But with 3.55s, it will be dynomite.
I ran all my cams with OOTB Edelbrocks, 1.6 arms, a very tiny lifter preload, and enough spring to go at least 7200. and yes, my Hughes HE2330AL cam went there no problem. the 1>2 shift was a blast. 2>3 busted the 245s loose and set them on fire, and the 2>3 was still more than just barking tires.
>next, I had to narrow the rear, move the springs and make room for 295s, which after that, only spun from 4000>5000 in Second gear.......
>Don't sell a 223*cam short. I put a double overdrive on that, and a specially tuned carb, still pulling thru the Airgap intake; and on one day trip, she returned 32mpgUS, cruising at 65=1600 .
I would still be running that 223 cam, had it not dropped lobes in 2004.
I appreciate it buddy! Sounds like you went thru the ringer on that one, yea im pretty much turned away from the 509 cam. I definitely wanna be able to cruise in parades, ect. I'll give hughes and Howard's a call tomorrow, I try to stay away from comp cams, post covid their products went soft lol. So far I'll be running a a833 with a 8 1/4 3.55 sure grip with 275/60/15 on a 10x15 wheel. Moved the springs in last spring. I appreciate the advice on the cam!!
junkyardhero
Well-Known Member
do yourself a favor and call Ken at Oregon Cams. hughes or howards is just gonna try and sell you what they have* not what you need.
*in the case of hughes they may even take your money and just sit on it till they grind the cam for you at some unspecified time in the future, likely after the time frame for refund from your payment service.
Slantsix64
Well-Known Member
keep it stock bottom end, get a reground camshaft stay under .500 lift for the 5.2 magnum has flat tops, Hughes spring and retainer kit, port the heads headers air Gap intake 650 double pumper and run it.
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