It begins again - 512 Stroker

-
pentastarpro

pentastarpro

speed trials
Joined
Oct 25, 2009
Messages
67
Reaction score
40
Location
Apple Valley,CA
Ordered my 440-512-5075 kit today. Need to make decision on heads. Early 70's 3462346 casting (right in pic) will need new guides installed or Late 78' 4006452 casting (left in pic) will need hardened exhaust seats installed. Both have 81.5cc chambers & will be ported using DC P4120437 plastic template kit. Not sure of the benefit of additional water circulating holes around spark plugs on 78' heads (see pic) but they do match the block. Any experience is appreciated.
 
sorry, missed the pic
100_2896.JPG
 
Just my opinion, if you are building a nothing motor just to have 512 cubic inch and want to run cast heads thats one thing. But to get any type of HP you are going to need a head like the trick flow with at least a 240 or the 270 cc intake runner. A bullshit EDDY RPM performer head for an oval port BBC is a 280 cc intake runner. My Eddy Rpm performer heads on my Big Mopar are only a 220 Cc intake runner, thats like a small block runner size. You need to decide what you are building here.
 
Do yourself a favor and buy some new aluminum heads. Trick Flow 240 heads are the best option out there right now but you could also get some Edelbrock RPM heads or maybe some 440Source Stealth heads. Sinking money into old cast iron heads is not a wise choice for a 512 engine.
 
Thanks for input. Decision was made long ago. My racing days are long gone. This is a "Coffee Cruiser" & I probably should have said that originally. My question still "is there a benefit to the additional flow holes along the bottom edge of the late head". I expect both sets can be made to breath well and satisfy this old school fool.
 
Change the title to “How to choke out a 512”. There is Absolutely no reason to build a 512 with those heads. They’re barely sufficient on a hot 440 yet alone a 512. Let use know how it works out.

Jake
 
Fisher said:
Just my opinion, if you are building a nothing motor just to have 512 cubic inch and want to run cast heads thats one thing. But to get any type of HP you are going to need a head like the trick flow with at least a 240 or the 270 cc intake runner. A bullshit EDDY RPM performer head for an oval port BBC is a 280 cc intake runner. My Eddy Rpm performer heads on my Big Mopar are only a 220 Cc intake runner, thats like a small block runner size. You need to decide what you are building here.
Click to expand...


Love this. This is the first time I've ever seen people, anyone here for that matter be honest about how anemic the heads are on a big block mopar.
 
How about posting the rest of your build information? For the money invested in old iron heads, any aluminum head would be worthwhile for the added detonation resistance, even a set of the 440 source stealth heads. I know someone with a set of stealth heads on a 512 inch 400 based engine. Even though they are less than optimum, they work better for cruising than the set of worked 906s that they replaced.
 
pentastarpro said:
Thanks for input. Decision was made long ago. My racing days are long gone. This is a "Coffee Cruiser" & I probably should have said that originally. My question still "is there a benefit to the additional flow holes along the bottom edge of the late head". I expect both sets can be made to breath well and satisfy this old school fool.
Click to expand...
I applaud your build and completely understand where you are coming from.

Of all the iron heads, the 346 and 452 heads are the easiest heads for the beginner to port and get some decent flows. The first time my son and I built a performance engine we used ported 452 heads on a 451/400 stroker. Poor thing only made 588 lb-ft and 621 hp on 91 octane pump gas. I don't recall us ever getting more than 748 hp with iron 906 heads on a 500" stroker. So as you can see, the iron heads aren't worth a damn.

I believe the extra holes were for cooling around the spark plug area in the motorhome engines. They probably will be of no advantage in your application.

I really like the Studebaker! When I was in high school Pop and I built a '53 for some Bonneville runs but that car never made it to El Mirage or Bonneville. We did make one 140 mph run between Palmdale and Desert View Highlands. Somehow the project got abandoned.
 
Can power be made with iron heads? yes, clearly it can.

But...money invested, reparability and drivability needs to be taken into consideration.

I had IQ do a set of performer RPM heads for me along with deep ported intake and a solid roller. I know what went into that money wise, what the flow numbers are and what the engine ultimately produced and where and how it produced it.

I'm not sure it was even possible with iron and if it was, the cost would be substantially higher without a doubt.
 
I appreciate the input from all. This is an "old school" build using a 78' motorhome 440 I've had in storage for 25yrs. Finally getting started after two other stroker builds, first one was a Speed-O-motive 451ci done 22yrs ago. Sticking with iron except for TM-7 intake, Dart adapter, & 1050cfm Dominator. A lot of you have said "use what you got" and this is it. Bump stick is original Purple stick 508*, 292/292, 108LC as in my previous builds so the heads may not be the choke point. Trany is done however still looking for vehicle, thinking D100. I will update on progress.

Thanks for comment on Stude'
In 68' she went 210mph at Bonneville with blown fuel baby hemi but couldn't make the return trip for record. She went 174mph at El Mirage that same yr. Nice ride, & good memories.
 
Well done. 200 mph is not easy. Pop and I spent a lot of time at El Mirage and I got to go to Bonneville with him and Norm Thatcher a couple of times.
 
We were active competitors from 64' thru 69' as Perkins & Sons Racing. We were members of Gear Grinders with turbocharged 170ci slanty in Blown Coupe & Sedan & I was also member of Rod Riders in 68' with baby hemi in Blown Fuel Coupe. Yeah, 200mph with less than 300ci is a daunting task w/ trophys but no record. Still building Mopar.
 
This will be a unique build and should be a riot to drive. If you need a full rebuild, no reason to not go with the upgraded internal assembly. I was looking at the 512 myslef and was going to upgrade ot the lightweight crank. It will definitely want the 1050 on top, maybe more. It's going to suck on those ports..hard.. between the stroke and the addition cubes. It will want a big carb.

I'm a bit sour on purple shaft cams. I've wiped 2 of them out in the past 20 years. I like the performance of the grind I've used, but wiping 2 cams sucks. I'd splurge for a roller or at least a different brand.
 
As I said "it's what I got" & I'll let the next owner do the upgrades ie- aluminum heads, FITEC, MPI.
Sorry to hear of your bad luck w/purple sticks, I've used them on all my SB, B, RB builds except the slanty without problems. Although, admittedly, most were years ago and quality has taken a noticeable downturn over the last 10+yrs.
 
re:IQ52
If I could get anywhere near 600hp with this combo I will be elated, over 700hp would be only a dream.

re:roccodart440
I've considered the Comp version @ .509, 284/284, 114LC due to availability & complete package price. I've never used their products but heard good & bad. Calculations indicate 1150cfm is better choice however I hope to benefit from a stronger vacuum signal for responsiveness. Right or wrong "it's what I got".
 
just curious.."just build what i got" would be the 440.
....is there a specific reason for the 512?
 
re:ir3333
No specific reason other than I still have two 72' (eastern) 400ci blocks w/under .030 wear but have already done that a couple of times. The 440ci has been patiently waiting for my attention while I watched the kit cost go up more than $500. The 512ci kit is most reasonable without having to clearance the internal block and going to external pickup so, for me, it was time to drop the hammer. This is not a macho "bigger, stronger, longer" exercise. It is more a resignation to a burning desire that has been simmering for decades --- but thanks for asking.
 
pentastarpro said:
We were active competitors from 64' thru 69' as Perkins & Sons Racing. We were members of Gear Grinders with turbocharged 170ci slanty in Blown Coupe & Sedan & I was also member of Rod Riders in 68' with baby hemi in Blown Fuel Coupe. Yeah, 200mph with less than 300ci is a daunting task w/ trophys but no record. Still building Mopar.
Click to expand...
Pop was with the Sidewinders. His '59 Plymouth went 146.10 at El Mirage in 1959. If I remember correctly, a few years later he was the first to drive 180 mph one way in an unblown stock bodied sedan.
 
pentastarpro said:
re:IQ52
If I could get anywhere near 600hp with this combo I will be elated, over 700hp would be only a dream.

re:roccodart440
I've considered the Comp version @ .509, 284/284, 114LC due to availability & complete package price. I've never used their products but heard good & bad. Calculations indicate 1150cfm is better choice however I hope to benefit from a stronger vacuum signal for responsiveness. Right or wrong "it's what I got".
Click to expand...

I've never used that cam. My stick of choice has always been the 284 ([email protected]) .528 , 112 or 114 (can't remember) That's pretty close to what you are thinking of except the hydraulic vs. solid. I really prefer a solid cam. Either way, I am a huge fan of wide LSA cams for street use.

You'll have no issues with responsiveness at all. That thing will pull tons of velocity. Mopars love a big carb because they dont' want a restriction before the port. The port is the restriction.
 
SAgfter
roccodart440 said:
Love this. This is the first time I've ever seen people, anyone here for that matter be honest about how anemic the heads are on a big block mopar.
Click to expand...
having my best friend who is an 18 time national record holder rework some sbc alum heads for me , and seeing what he does to heads , I GOTTA AGREE , MOPAR BIG BLOCK CAST HEADS ARE ALL JUNK ! Even reworked to the max , they wont perform like a rat head !
 
pentastarpro said:
re:IQ52
If I could get anywhere near 600hp with this combo I will be elated, over 700hp would be only a dream.

re:roccodart440
I've considered the Comp version @ .509, 284/284, 114LC due to availability & complete package price. I've never used their products but heard good & bad. Calculations indicate 1150cfm is better choice however I hope to benefit from a stronger vacuum signal for responsiveness. Right or wrong "it's what I got".
Click to expand...


That cam would be a huge step backwards. There is no way you need a 114 LSA with those heads.

There is nothing wrong with that cam you have on a 108. I'd stick it in at 106 and gear it accordingly.

You've seen what IQ can do with those heads. You'll be fine.
 
yellow rose said:
That cam would be a huge step backwards. There is no way you need a 114 LSA with those heads.

There is nothing wrong with that cam you have on a 108. I'd stick it in at 106 and gear it accordingly.

You've seen what IQ can do with those heads. You'll be fine.
Click to expand...


The 114LSA angle will definitely leave power on the table. While yellow Rose's preference is to most often utilize smaller LSA's, he's not wrong, it would be a huge step backwords power wise and in that combo.

One of the issues he may agree with here is [email protected] is pretty small for a 512ci stroker, even for street use.
 
You must log in or register to reply here.
-

Back
Top