360 budget build questions.

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Cope

Cope

Fusing with fire
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yes folks its another, what to do-build 360 thread.

Car, 1971 Dart swinger.

I have a tired 318, MSD 6AL, Headman longtubes into 2 1/2" dual exhaust to the bumber ( no cross over), Wyand +plus dual plane manifold toped by a Holley DP 650 (4150).

904 w 7.25' @2.73 rear gear.

I live at 6,250' alt. but would like to drive the car to sea level.

My 360 that im building is worse than I thought, Surprise!!!
Rod journal 1-2 is smoked, rods 1-2 are beat to shiza on the big end.
Rods 1-3-2 are tight on the wrist pin, so im thinking....

Regrind crank from napa. 250.oo
3 new rods 35-40.00
ballance rods at home.
shot peen rods 20.00
hot tank block 40.00
pressure test block 80.00
cam bearings, core shift check, deck check ?

The cam im looking at is Comp XE268H, or summit part number, CCA-SK20-223-3. (230.oo)

My stock pistions look good, but...
What are your folks thoughts on some "rebuilder" 10, 10.5-1 "OEM" pistions?
remember my alt.

I figure with some quality bearings and rings that package should get me a decent short block for @ 1,000 bucks?....

All thoughts and ideas are welcome.
Thanks for the time and advice.
 
If you have the talent/know how on balancing rods, your in good shape. I'd skip OEM slugs. IMO, A New set would be the best ideas. Lighter weight and stronger. Like KB HyperU's. It also beats milling the heads a lot! (Same with the rods but there a bit pricey compared to $30-$40 OE replacements.)

Find a 8-1/4 rear at a min.
 
Try and get your cr up
Looks like 6250 is worth about 1.3 Dynamic compression points. That means you can run at least that much more than a lot of us at lower elevations. To get the dynamic up to the fun zone,youre gonna need about 11.0 to 11.5 static . Wont happen with flat-tops and open chambers. I think KB makes some pop-ups that could get you there.Easy on the cam though. Too late an intake event will drop the dynamic pretty quick at your altitude.
When you go down the hill though, stay out of the secondaries, or risk engine damage.Disconnect/disable the secondaries.It will pull plenty hard on the 2bbl.Consider a dash mounted dial-back timing device.If your gonna run on the edge with 11.5(I certainly would)consider the D-back mandatory.
11.5 static, with a 60* intake closing will get you about 9.5Dynamic at sea level, and 8.25D at 6250ft. The 9.5 is too high at sealevel, for pump gas and full timing, to run WOT. The 8.25 is on the low side for 6250 but will pull plenty hard, and annhilate just about anything at 6250 that is not purpose built.
My combo is right at 10.7static which calculates to 8.8Dynamic,corrected to sealevel.Running aluminum heads,I have no problems running 87E10,Wot,full timing.Generally iron open chamber heads need to run a little more conservative on the dynamic. So at 8.25, you would be about a half point less than me, which should be perfect.
If you run stock type, down in the hole,dished pistons; the dynamic will be laughable(probably sub 6/1 with the factory cam, and less than 5.5 with the 268 cam),and so will be the performance.Stay away from big cams. Stick to the factory 2bbl cam, as to duration.
Spend a little more on the pistons. You wont regret it.Your intake closing point will need to be carefully coordinated at 11.5cr.
Oh one more thing; until you get that 7.25er replaced,stay away from serious rubber.
Oh, another thing, What is your thinking as to the 268 cam choice?
Play with this ; http://www.jeepstrokers.com/calculator/
 
I got a question about the OP builders crank.

Would the regrind from NAPA avoid the costs of a rebalance? Just wondering if that would lower the costs enough to justify not spending the extra 75 dollars on a scat cast crank over the NAPA regrind.
 
Thanks folks.

Ill start with the last question first as its the easyest to anwser.
The NAPA crank comes from a regrinder at .010-.010 I have serious doubts that my crank will grind out anything close to that. My buddys bringing over a nice mic today and I can realy start to see how far out it is.

The cam honestly is one that I saw listed on a bunch of 360 build threads. I have a problem picking cam shafts, I tend to pick on the far side of crazy and not be happy. This time I figured I just pick one that was common and not be let down. Im gonna have to do some more reading on lift and duration. (I do have tje factory 2 bbl cam, 2 accualy. one out of thos 360 w lifters and another running currently in my 318. I guess i could reuse the cam and put that money twards slugs?. I do want a nice lope at idle tho...)

I realy wanted to stay away from fancy slugs on thos build and do a true budget build but if you folks think its the way then dam, the wallet may cry..
I do not want to go crazy on machine work with this block or heads, valve train.

I will do some serious thinking on CR and some nice slugs.

The machine shop is an hour and fortey five min away and no friend to my wallet so any thing I can do to avoid "custom" machine work is a plus.



Thanks again for all the time and advice.
 
Here's the rub as far as i see it - the factory pistons are pressed on. When you press them off chances are very good they will deform. If it was me I'd simply look for another 360 running for under $500, and then add your bolt ons to it. Sometimes we do things to make the effort, and the reward is not really that much. Reusing stock pistons, and assuming the guy that's taking them off won't deform one by accident may cost a lot more, and if he does get them off, you're still stuck mounting the new rods and beign left with exactly what you started with. Another thought is a runnign Magnum engine, in which case you'd need an intake and a flex plate to drop it in. They're probably a bit more common and cheaper than an LA 360.
Up to you.
 
There's more to balancing rods than simply making them all weigh the same. You do know that right? It take some pretty specialized equipment to do it correctly.

Certainly not saying you cannot or do not know how.....I am just throwing it in the mix.
 
What heads are you running? If your keeping the 2.73 gears, stock converter, and low compression pistons. i would look for a smaller cam with a tight lobe seperation. This will help boost cylinder pressure. Maybe an old isky grind like the 264 megacam on a 104 IC. This cam has low lift so you wont need any special head work or springs. i really doubt that 7.25 will last long though.
 
I just checked the heads and the casting number under the runner is 348915-A,
Not 3418915 like i see in the id chart?
they do have 1.88 int valves.

The block i think is 1977 from what I can determine.

The 2.73s are going in the bin as soon as i can afford as is the 7.25.

Its looking like I may just buy a set of dome slugs and mout em to a set of reman rods on a reman crank.

Im having a hard time figuring what size dome is in order and that DCR is mind bending trying to figure out.


AJ when u say my alt is equal to 1.3 DCP dose that mean at 11-1 im roughly 10.8-1 SCR?

is there a chart that will tell me the cc of my head from castin number?


so now i sit at.
400.00 reman crank and rods W bearings.
360.00 KB dome slugs 10.5,11-1???
80.00 pressure test block
40.00 hot tank block.
cam bearings, over bore, rings, oil pump, deck heigth=$$???

that still fits my budget if i reuse one of my 2bbl cam an lifter sets..

Thanks again for the time and advice.
 
stock rods are balanced. rule of thumb is if new pistons are over 10% lighter than stock pistons go for rebalance. 1970-71 340 heads and 1971 360 heads are 3418915, 340 machined for 2.02" and 360 machined to 1.88", stock chamber is around 71 cc, keep it simple
 
when I threw the 10.5-11-1 CR numbers at summit tech they came with pistions,
KB107 or SLP-H-166-CP
both should resuld in 10.5-1 SCR.
They also came with XE268H as the cam for that motor...

Not saying summit is right, looking for thoughts and ideas.
Thanks again.
 
It might be easier to advertise for a Magnum or LA rotating assembly that someone with a stroker can;t use. Get it in running shape, and run that with the right balancer and flywheel for whatever you end up on it. I think the best route is something complete and in good shape to run. Anything else and the "might as wells" will blow the budget.
 
I agree with Moper on this. If the budget is a real tight one and a cause of concern, then a junk yard 360 Magnum with as little miles on it as possible is what inwould look for. Resell the old engine in parts or as a whole to offset costs.

The Magnum engine offers a 9.0-1 ratio. I would avoid high ratios as suggested above. No offense to the suggester. The Magnum also has a Hyd. Roller cam. Just purchase the cam & matching valve springs and reuse everything else. It will pan out dollar wise to be approx. the same as getting a new cam and lifted set with correct length pushrods and etc.... And be a wide margin ahead of the Hyd. Set up.

Add the bolt on intake carb and headers like anything else and you should be good to go from there.
 
Rumblefish.
to get a junkyard motor is not easy or cheep we talkin many trips= maybe find what i want, plus the cost for a junkyard motor is 500-700 an i still have a junkyard motor...

I have this 360 on the stand.

Please advise.

Thank you.
 
Cope said:
Rumblefish.
to get a junkyard motor is not easy or cheep we talkin many trips= maybe find what i want, plus the cost for a junkyard motor is 500-700 an i still have a junkyard motor...

I have this 360 on the stand.

Please advise.

Thank you.
Click to expand...

I think rustyratrob said LKQ (which is a corporation that bought out many junkyards) has online offerings of magnum engines with some kind of warranty

I have seen some on eBay for a few hundred bucks

Rusty got one of their motors for his project car, tore it down, and was so impressed with the state of the motor that he regretted tearing it down to verify the status of the internals.
 
Ithink we need to talk.
What you are trying to do, and what I think your are trying to do, may not be the same.
The biggest stumbling block I see is the dual purpose nature of this build. If you optimize for 6250, you will have to be real careful at sealevel.If youre just going down on the occasional trip and are not intending to rip around thats one thing.But if ripping around at sealevel is on the agenda, then we have to keep that in mind.
If you optimize for sealevel, it will be pretty soft at home.So your fun factor will be compromised.
So whats a guy to to? I think you will need to sacrifice something. The header proclaims 360 on a budget.So not knowing the budget, we could be tossing ideas around that just wont fit in your budget.
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The KB107s are flat tops with 5cc eyebrows. Theyre in my combo. They are making 10.7 Scr with 65cc chambers and a +.005 deck height.
Theyre wrong for open chamber heads.Open chamber heads in unmachined state are closer to 70cc or more. Cant get to 11 with those slugs unless you machine the heads(momoney).And you will have a terrible quench clearance.Which may lead to detonation problems down at the bottom of the hill.I am a firm believer in tight quench. Smarter men than me have proposed that tight quench helps to avoid or at least delay detonation with high Dcrs and low octane fuels.And that has been proven to be correct in my build.
To that end,you will need domed slugs, and probably have to machine them to fit the chambers. I have an old KB catalog. It lists two pop ups for 360s; The 190s, and the 191s. While either will be better than the 107s, I feel the 191s are the ones you need. They will have to be carefully fitted to the chambers.(not cheap) Piston machining should not be finalized until the cam decision is made, because the intake closing point determines the Scr target.
The cam choice should be on the small side, so that if you decide to go bigger, the Dcr will fall. If you go the other way, The Dcr will rise and you may run into detonation.If you get greedy on the cam size,You may end up with a soft bottom end; not the hot thing for a streeter. If you feel you have a suitable used cam(and i think the 2bbl cam is a bit too small;The duration might work, but the lift is rather weak ), stick it in the block and degree it. Find the point of intake closing in crank degrees, and plug it into the formula.If it falls somewhere between 45* and 55* ABDC, your close.Then manipulate the deck and dome numbers in the formula to arrive at a Static cr that falls between 11 and 11.5. If your cam is closer to 45* then shoot for 11.5. If your cam is closer to 55*, shoot for 11.
So once the the Scr target is established, The piston tops can be machined to set the quench clearance and to provide the chamber volume to arrive at the target
Alternatively, and this is what I would do, you could order a custom cam. One that will do exactly what youre looking for.Find a cam company that grinds for our bigger lifters,call them up,and explain to them your needs. They will grind you THE cam; one that you will never want to change.
I think it would be a good thing if you found a Mopar machine shop.Tell them what you want, and let them handle the details.Do not let them talk you into machining stuff for the sake of machining stuff. Some shops I have come across want to machine everything in sight. Ive had a couple of blocks ruined by improper machine work.With the plans you are making, the only block machine work I would allow is very light cuts to the decks IF they need it.If your new crank is straight and spins nice in the saddles, do not let them line-hone it. If they tell you they have to,before they shave the decks, run. Find a different shop.
And finally there is one other option.Actually there are 2 options. The first and most obvious is turbo charging.And the second is CID. Neither of these is in the budget, unless you can find a guy with a stroker kit for sale. And in fact there is a guy on FABO right now willing to part with one for less than $1100bucks.Member RJK3
With a stroker kit,the crs tend to to be easier to hit with less machining costs.A high Dcr wont be required either because the CID is working for you. 408cid is a lot of cids.
So plug that 4 inch stroke into the formula with say 70cc heads and a 52* intake closing point, and see what comes up. That kit if still available is only a little bit more than what you are at now,dollar wise.
I see RJK3 says his kit is 9.0 SCr with 70cc heads. I plugged the numbers into the formula and with a 52* closing intake,it works out to a Dcr at sealevel of 7.9, and at 6250 its 6.65. So, the pistons leave a bit to be desired, but at 408cid its 16% bigger than the 360, which even at 6250 is plenty of motor.And you should have no problem burning any crappy gas. Its still for sale. Now at $1050.
 
Cope said:
Rumblefish.
to get a junkyard motor is not easy or cheep we talkin many trips= maybe find what i want, plus the cost for a junkyard motor is 500-700 an i still have a junkyard motor...

I have this 360 on the stand.

Please advise.

Thank you.
Click to expand...


It's not hard to find a good junk yard engine near you...

Here is a link to a nation-wide data base of salvage yards that you can search for an engine in your local area with low mileage (or any part)... Some may even offer a limited warranty and possibly ship, you can find one close to you.

www.car-parts.com


My brother is an insurance adjuster and uses this site all the time. He showed it to me.

Keep in mind that if you get a truck magnum engine and put it in a car, you will have to change the oil pan and oil pick-up tube to fit the car. The hump for the truck pan is in adifferent spot and will not work in a car as it will interfere with the k-frame.
 
Cope said:
Rumblefish.
to get a junkyard motor is not easy or cheep we talkin many trips= maybe find what i want, plus the cost for a junkyard motor is 500-700 an i still have a junkyard motor...

I have this 360 on the stand.

Please advise.

Thank you.
Click to expand...

Do you have a phone or computer?

http://www.lkq.com/

You type in your info - use a 1986 W250 for an LA360, or a 1998 Ram 2500 PU for a 5.9L magnum, and stick in your contact info and the yards will contact you with what they have. Then ask them questions - ask about warranty and history. A "junkyard" 360 (using that as a descriptive term referencing its location - not quality) is what you need budget and performance wise. What you have is a block and maybe some usable rods at best. It's trash as it is. You need a complete running engine.

Many can spec a mean *** 360 for you but you have a silver spoon attitude and a toothpick budget.
 
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