cast crank 440 / heads recommendation 9.1 CR possible?

Posted By: funkyjbp

cast crank 440 / heads recommendation 9.1 CR possible? - 10/18/11 07:23 PM

Everyone, the 413 in my 71 short-wide bed shot craps so I'm looking to drop in a good-running mid-70s cast crank 440/727. I would like to run a modest cam and raise the compression a bit while motor is out of truck. I have 452s on it now. Is there a factory head that would increase the compression to near 9.1? Can i mill my 452s enough to get 8.5 without having significant valvetrain and intake manifold issues? I don't want o spend a fortune on the truck, just put it back together for now while i finish the new 360/A500 swap in my 77 shortbed. any suggestions are welcome! Thanks, JP in the land of oz.

Posted By: Mr.Yuck

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/18/11 07:43 PM

I wouldn't go crazy with the milling. Maybe .030 thou and use a steel headgasket and you should be fine. If the 440 is running I'd drop it in as is, You aren't going to pick much up going from 8.5 to 8.8-9:1. Now if it's apart and you want to clean it up some then have at it.

Posted By: joedust451

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/18/11 08:10 PM

Like mentioned, if it runs good just drop it in, If anything you could install headers/intake/carb as ungrades along with a better ignition & dist. for easy timing/curve adjustments, Trying to raise the compression on those smogger 440s is a waiste of time, the ONLY option for "true" results is changing the pistons, You can install closed chambred heads or Mill open chambers till your blue in the face, but in the end the pistons are just too far down in the hole for "real" noticable results & the headaches of all that extra work/exspense IMO isn't worth it, I myself tried it out on a 77 .030" 440 with stock pistons, had all the bolt-ons & the .488 summit cam, It was a fresher rebuild that was in the truck when purchased, It had the .039" gaskets, I pulled the heads off (452s), had them milled .050" & installed a steel shim gasket, I'm sure it raised the compression a solid point by the #s, Yes the truck damn near ran the same

, don't waiste your time, run it as is.

Posted By: funkyjbp

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/18/11 09:28 PM

Mr.Yuck and Joedust. Thanks for your advice. I'm feeling the same way you guys do. My motor is an older rebuild to stock specs and it's super-clean inside. My truck has hooker super comp full-length headders, i have an edelbrock performer RPM manifold, 750 holley, and elec ignition already in it. I want to run a better cam and have a B&M conversion flexplate and will run a 360 motorhome converter with the weights knocked off it. Truck will have a 3.91 sure grip also with 295s on the rear. I have the 63 model 413 heads which are in good shape but 452s flow better. The cam manufactures keep saying 9.1 and 9.5 to 1 compression and i'm probably at 8.1-8.25 to 1 now. I'll probably just slap it together as-is and see what it does. I don't want to "Snowball" and spend a bunch of money on it because my 77 is about to get a major tear-down for paint and detailing under the hood followed by the new 360/A500 combo going in it. Thanks for your advice. Jp in the land of oz.

Posted By: dogdays

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/18/11 09:33 PM

Over the years compression on cast crank mid-'70s 440s has been calculated many times and the highest anyone ever comes to 8.5:1 is 7.9:1, something like that. Pistons have been as far as 0.170 in the hole, that's about 45cc right there.
So the real open chamber head volume is 88-92cc, the real closed chamber head volume is around 84cc. Cylinder volume is 902cc. To get true 9.5:1 you need 106 cc above the piston. So 45 cc + 5 cc (thin head gasket) +84cc = 134 cc. You need to reduce volume by 28cc. If we guess about 10 cc per 0.040 thickness, you have to mill it 0.112" to get to 9.5:1. And that's with the small head and thin head gasket. Using that with the piston down so far will get you 7.73:1 if my calculations are right.
Even if the piston is down only 0.090, which is about 23cc, you need to use the small head and the thin gasket and mill 0.020. Or use the 90cc head and mill 0.045, something like that. Don't forget you also have to mill the heads' intake faces.
Bigblocks came stock with the thin head gasket, so nothing to be gained there.

In short, use what you have until you can get a better set of pistons.

Posted By: Dunnuck Racing

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/18/11 10:07 PM

I have to agree with the other guys,if you are not rebuilding the shortblock,not much can be done for compression. At least not enough to make a difference.
With the gearing you have it should move along pretty decent,and your low compression means you can run low grade fuel and be okay.
A cam change in a low compression engine won't gain much,maybe a few hp but not enough to justify the cost.You would really need to find something smaller than what came stock to build some cylinder pressure and I just don't see the results as being that much better.

Keith

Posted By: DaytonaTurbo

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/18/11 10:08 PM

Yep, basically no amount of milling is going to correct the problem of the pistons being so far down in the hole. Even if you mill the chambers tiny, you still have a horrible combustion chamber because of how low the pistons sit. Run it as-is or spring for a new set of pistons.

Posted By: dogdays

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/18/11 10:12 PM

One thing i was going to add, use a cam with a small intake lobe and narrow LSA. 110 degrees would be good IMHO.

Something like 208/214 @ 50.

R.

Posted By: RBDART1

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/25/11 10:03 AM

I know what u r dealing with in the struggle for more comp,been there done that and contrare to many mopar guys opinions on smogger 440's low comp motors there is power to be had in raising comp even if it's not alot or seemingly worthwhile I assure u it is and u prob have the parts in ur 413 to make what ur looking for cheap, using 516 heads will raise comp 8/10's of a point,my 76 440 pistons were .143 in the hole and with the 452's it computed to 8.1comp and I wanted to run a 509 cam so I put 516's on it with the small exhaust valve with better springs and steel shimgasket got 8.9 comp,I was on a budget of next to nothing so I used what i had,with a alum dual plane intake[performer] 750dp,headers,2400 convertor,727 w/shtkt,4.10 gears/sg in a 71 dart worked out pretty good for what it was,sounded good ran good had alot of fun with it and this motor was 100,000mile junkyard dog that ran the best et of 13.64 and alot of hi 13's...and everybody told me it was too much cam and not enuff comp and it would be a dog...and on paper it should of been but I've seen smogger motors that would suprise ya,doesnt hurt to try it what'd ya got to lose ? just because a cam mfg recomends a specific comp ratio for a specific cam doesnt mean it wont do well on less not saying u should'nt try to match combos to get max perf by no means but sometimes u gotta do what u gotta do with what u have til u can afford to build what u want...u could also mill the 452's .060 and gain a full point of comp with a shim gasket, even if ur comp is only 7.8 now u would still get 8.8,I think thats worthwhile...jus my opinion

Posted By: quickd100

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/25/11 11:19 AM

I'd have to go back and measure my old 515 heads but I did mill them until after deshrouding, they were at 65cc's. With the steel shim head gasket on my '77 440hp shortblock I achieved 9.2-1. The 516's made it about 10 years before I cracked one in the exhaust port up through the seat.
It's alot less trouble to find a set of pistons. Dave

Posted By: joedust451

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/25/11 03:30 PM

Quote:

I know what u r dealing with in the struggle for more comp,been there done that and contrare to many mopar guys opinions on smogger 440's low comp motors there is power to be had in raising comp even if it's not alot or seemingly worthwhile I assure u it is and u prob have the parts in ur 413 to make what ur looking for cheap, using 516 heads will raise comp 8/10's of a point,my 76 440 pistons were .143 in the hole and with the 452's it computed to 8.1comp and I wanted to run a 509 cam so I put 516's on it with the small exhaust valve with better springs and steel shimgasket got 8.9 comp,I was on a budget of next to nothing so I used what i had,with a alum dual plane intake[performer] 750dp,headers,2400 convertor,727 w/shtkt,4.10 gears/sg in a 71 dart worked out pretty good for what it was,sounded good ran good had alot of fun with it and this motor was 100,000mile junkyard dog that ran the best et of 13.64 and alot of hi 13's...and everybody told me it was too much cam and not enuff comp and it would be a dog...and on paper it should of been but I've seen smogger motors that would suprise ya,doesnt hurt to try it what'd ya got to lose ? just because a cam mfg recomends a specific comp ratio for a specific cam doesnt mean it wont do well on less not saying u should'nt try to match combos to get max perf by no means but sometimes u gotta do what u gotta do with what u have til u can afford to build what u want...u could also mill the 452's .060 and gain a full point of comp with a shim gasket, even if ur comp is only 7.8 now u would still get 8.8,I think thats worthwhile...jus my opinion

Check out my 71 dart in my sig., ALL it had was a junkyard 360 magnum & bolt-ons, very little stall & 3.73 gears, So i will say your smogger 440 WAS a DOG!!!!!!!!!!!!! Sorry

The later 440s were horrible about having bad quench, I'm sure you didn't do a "back too back" comparison from the 452s too 516s did you, I'd bet you would have been surprised of the results, been there, done that

Posted By: JohnRR

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/25/11 04:11 PM

Quote:

Quote:

I know what u r dealing with in the struggle for more comp,been there done that and contrare to many mopar guys opinions on smogger 440's low comp motors there is power to be had in raising comp even if it's not alot or seemingly worthwhile I assure u it is and u prob have the parts in ur 413 to make what ur looking for cheap, using 516 heads will raise comp 8/10's of a point,my 76 440 pistons were .143 in the hole and with the 452's it computed to 8.1comp and I wanted to run a 509 cam so I put 516's on it with the small exhaust valve with better springs and steel shimgasket got 8.9 comp,I was on a budget of next to nothing so I used what i had,with a alum dual plane intake[performer] 750dp,headers,2400 convertor,727 w/shtkt,4.10 gears/sg in a 71 dart worked out pretty good for what it was,sounded good ran good had alot of fun with it and this motor was 100,000mile junkyard dog that ran the best et of 13.64 and alot of hi 13's...and everybody told me it was too much cam and not enuff comp and it would be a dog...and on paper it should of been but I've seen smogger motors that would suprise ya,doesnt hurt to try it what'd ya got to lose ? just because a cam mfg recomends a specific comp ratio for a specific cam doesnt mean it wont do well on less not saying u should'nt try to match combos to get max perf by no means but sometimes u gotta do what u gotta do with what u have til u can afford to build what u want...u could also mill the 452's .060 and gain a full point of comp with a shim gasket, even if ur comp is only 7.8 now u would still get 8.8,I think thats worthwhile...jus my opinion

Check out my 71 dart in my sig., ALL it had was a junkyard 360 magnum & bolt-ons, very little stall & 3.73 gears, So i will say your smogger 440 WAS a DOG!!!!!!!!!!!!! Sorry

The later 440s were horrible about having bad quench, I'm sure you didn't do a "back too back" comparison from the 452s too 516s did you, I'd bet you would have been surprised of the results, been there, done that .

There wasn't a 440 built by the factory that had acceptable quench .

Posted By: dogdays

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/25/11 04:14 PM

There was no squish to be had at all from '68 on up, and the piston-to-head clearance of the earlier engines was excessive for decent squish.

R.

Posted By: JohnRR

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/25/11 04:43 PM

Quote:

There was no squish to be had at all from '68 on up, and the piston-to-head clearance of the earlier engines was excessive for decent squish.

R.

Wasn't the 66-67 440 built with a piston .090 in the hole ?

Posted By: joedust451

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/25/11 08:07 PM

Quote:

Quote:

Quote:

I know what u r dealing with in the struggle for more comp,been there done that and contrare to many mopar guys opinions on smogger 440's low comp motors there is power to be had in raising comp even if it's not alot or seemingly worthwhile I assure u it is and u prob have the parts in ur 413 to make what ur looking for cheap, using 516 heads will raise comp 8/10's of a point,my 76 440 pistons were .143 in the hole and with the 452's it computed to 8.1comp and I wanted to run a 509 cam so I put 516's on it with the small exhaust valve with better springs and steel shimgasket got 8.9 comp,I was on a budget of next to nothing so I used what i had,with a alum dual plane intake[performer] 750dp,headers,2400 convertor,727 w/shtkt,4.10 gears/sg in a 71 dart worked out pretty good for what it was,sounded good ran good had alot of fun with it and this motor was 100,000mile junkyard dog that ran the best et of 13.64 and alot of hi 13's...and everybody told me it was too much cam and not enuff comp and it would be a dog...and on paper it should of been but I've seen smogger motors that would suprise ya,doesnt hurt to try it what'd ya got to lose ? just because a cam mfg recomends a specific comp ratio for a specific cam doesnt mean it wont do well on less not saying u should'nt try to match combos to get max perf by no means but sometimes u gotta do what u gotta do with what u have til u can afford to build what u want...u could also mill the 452's .060 and gain a full point of comp with a shim gasket, even if ur comp is only 7.8 now u would still get 8.8,I think thats worthwhile...jus my opinion

Check out my 71 dart in my sig., ALL it had was a junkyard 360 magnum & bolt-ons, very little stall & 3.73 gears, So i will say your smogger 440 WAS a DOG!!!!!!!!!!!!! Sorry

The later 440s were horrible about having bad quench, I'm sure you didn't do a "back too back" comparison from the 452s too 516s did you, I'd bet you would have been surprised of the results, been there, done that .

There wasn't a 440 built by the factory that had acceptable quench .

This is true, but i would rather have the piston .080" below then .160", & the only other exception being the 440 6-pack, They weren't doggs, But i've said before i would rather have a stock 68-69 bottom end then a 76-77, I'm just speaking in terms of power output mainly, maybe i shouldn't have brought up anything about quench & through that out of the equation.

Posted By: quickd100

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/26/11 02:27 AM

With the '77 hp shortblock and the homeported and milled 516's with 2.08/1.74 valves, I added a 509 cam and an M1 single plane and a 850 Holley. Behind that was a TA 10" and 4.56 suregrip. My truck ran 12.20@106.88 in the 1/4 at 3600lbs. Dave

Posted By: Robbins

Re: cast crank 440 / heads recommendation 9.1 CR possible? - 10/26/11 03:20 AM

Quote:

Everyone, the 413 in my 71 short-wide bed shot craps so I'm looking to drop in a good-running mid-70s cast crank 440/727. I would like to run a modest cam and raise the compression a bit while motor is out of truck. I have 452s on it now. Is there a factory head that would increase the compression to near 9.1? Can i mill my 452s enough to get 8.5 without having significant valvetrain and intake manifold issues? I don't want o spend a fortune on the truck, just put it back together for now while i finish the new 360/A500 swap in my 77 shortbed. any suggestions are welcome! Thanks, JP in the land of oz.

I would just probably get a cam that works with the decompressed motors and have fun with it while you work on the 77 for now. Or better yet......sell me the 71.