Everyone else asks, (512 build) why not "ask the forum", lol

[rikkitik]

Hi all, I have some engine combo questions, and though it's for an ebody, I thought I'd ask here.
The car, '71 Challenger (around 3400lbs right now) upgraded suspension and brakes, (QA1 4 link rear), TKX, S60 w/3.54's.
STREET/strip (90/10 build).
Currently +.030 440, TF240's, Hughes DPM ProMaxx 6 pack, 9.8:1, UD SFT 243/247 .586/.594 108lsa in @ 104, (1.6's with B3 correction kit), 1 7/8" ARH.
I'm building an aftermarket block 512(511), 10.4 compression (Molnar 4.25/4.375 7.1rods)
I would like the power peak to be in the 5800-6000 range (SR Cam) with decent "over-rev" to 6300-6400, rev limiter will be 6500.
The cam numbers I'm looking at are Bullet solid roller (279/285) 249/255 .644/.645 net lift, or (283/287) 253/257 .645/.645 net, 110lsa and in at 106. I'm looking to be around 8.0 DCR, 175-ish psi.
Where I get hung up, is on the top end setup.
I like the idea of being able to run the 6 pack (the car has a T/A hood, so a 3" K&N fits), but also having the option of a TF or Victor manifold if I choose.
BUT, I'm not sure the std. port window 240's get me to my goal? (without more cam than I want)
I really do prefer the "feel" of a DP vs SP manifold.
In talking with Dwayne Porter, (Dwayne, I can't say enough about how helpful you are, always great to talk to!) and he suggested the Indy MW DP with 270's as a strong combo, (which does sound great, but I've read that Indy's QC is spotty). At $1100 for the manifold, "spotty" doesn't work for me.....lol. Any "hands-on" experience to share?
270's with a Super Victor or TF manifold looks like "just barely" hood clearance wise, but is "doable".
Comments or suggestions?
TIA
(PS, I'm building a strong all around ride that can give a Hellcat "pause" (all within legal limits of course)....... I've heard the "boomer" descriptor a little too often, lol)

 

[TT5.9mag]

You either need the 270s and intake that Dwayne (@PRH on here) suggested or you need a whole lot more camshaft on 512 inches to get where you want. And there’s no chance a six pack gets it done. IMHO. Llisten to Dwayne.

 

[rikkitik]

Thanks, I am listening to Dwayne, the DP MW/270's is my first choice, but not if it needs $800-$1000 in work (some assembly required). That's why I was asking for first hand experience (with recent castings) or potential alternatives.
Thanks again - Rick

 

[Cranky]

What I want to know is how your E car is 3400? The lightest one I ever had was 3560 with a 340 in it. It did have AC and PS though....but no carpet lol

 

[rikkitik]

"around" 3400 (3448)
Borgeson conversion -18, Dr Diff Viper brake conversion -38 (iron hubs and calipers were insanely heavy), aluminum heads, pump housing, pump, manifold, etc. Headers not manifolds, fiberglass hood......
The TKX is about 18 lbs light than the 18 spline, the S60 is much lighter than an original Dana, no A/C....... it all adds (minuses?) up.

 

[PRH]

Looks fantastic!!!

 

[rikkitik]

Thank you Sir!
Much appreciated (as is the time and information you're always so generous with!).

 

[Cranky]

3448 ain't bad.....Congrats and it's a looker!

 

[rikkitik]

Thanks!
It does look a "bit" different now. I stepped up to 18" wheels (17's in pic) so I could go wider on the front, 18x9's and 18x10.5's. 40 aspect ratio, so decent sidewall.
Interestingly, 18" 305 DR's have a .75 wider treadwidth than 17" 305 DR's.
So between the tires and the 4 link, it rides, handles, and hooks better than the previous setup.
(yes, USCT SF connectors and torque boxes added some weight back, lol. But definitely money well spent)

 

[Fast340cuda]

I just assembled a 440 based 493 using trick flow 270’s and the Indy dual plane intake. My particular intake was cast really nice, only needed minor gasket matching and will just barely clear the hood on my 71 demon with a drop base air cleaner.

In regard to your camshaft, I would look for something with a little more duration at .050 if you plan on spinning it over 6000 RPM. My “streetable” solid flat tappet comes in at 275 at .050. and is spec’d for shift points just over 6000 RPM.

 

[rikkitik]

Excellent information, thanks! (Nice build)

 

[famous bob]

Excellent information, thanks! (Nice build)

you would be surprised at what a victor intake ,gasket matched , and a big carb. , solid street roller , or fuel nj. would do
Low end you have to control , pulls I don't know how far ^^^^

 

[BSB67]

The Indy DP works pretty well to 650 - 675 hp—ish. Milling the divider down helps power up top. You’ll need a single plane above that.

An unmodified 6 pack will start loosing ground at about 575 hp to the other manifolds.

 

[TT5.9mag]

An unmodified 6 pack will start loosing ground at about 575 hp to the other manifolds.

Have you run the 6 pack on a big cu in engine at that (or more) HP level?

 

[BSB67]

Have you run the 6 pack on a big cu in engine at that (or more) HP level?

Yes. At that level, not more.

Not saying it cannot do more. But after jet tuning on the dyno, that is about where it landed, maybe 580. Removed it and installed the Holley SD with small Venturi 950 and 3/4” open spacer and went 600+ after a couple jet changes. Same with the Indy 2D. The 2D matched SD from about 5,000 rpm+. The 6 pack and the 2D did better than the SD below about 4,500.

I’m going from memory. I can pull the runs and get more specific.

 

[TT5.9mag]

Yes. At that level, not more.

Not saying it cannot do more. But after jet tuning on the dyno, that is about where it landed, maybe 580. Removed it and installed the Holley SD with small Venturi 950 and 3/4” open spacer and went 600+ after a couple jet changes. Same with the Indy 2D. The 2D matched SD from about 5,000 rpm+. The 6 pack and the 2D did better than the SD below about 4,500.

I’m going from memory. I can pull the runs and get more specific.

No need to pull the runs that was more than enough information, thank you. Your experience mirrors what I’ve seen in all the testing I’ve been privy to. How big was your test engine?

 

[BSB67]

4.25” arm, 508.

 

[74RRunner]

I can't help much with your specific question, but I think it's worth mentioning that if your goal is to compete with a hellcat, you have a HUGE weight advantage. Those cars are all over 4,400 lbs with some over 4,600.
550 hp should get you a comparable P/W ratio to a 707hp hellcat.

 

[Mopar603]

"around" 3400 (3448)
Borgeson conversion -18, Dr Diff Viper brake conversion -38 (iron hubs and calipers were insanely heavy), aluminum heads, pump housing, pump, manifold, etc. Headers not manifolds, fiberglass hood......
The TKX is about 18 lbs light than the 18 spline, the S60 is much lighter than an original Dana, no A/C....... it all adds (minuses?) up.View attachment 1716460566

I usually prefer old school stance & wheel/tires (yeah I know those look similar to minilites, but larger diameter) but you NAILED it. Thing is perfect

 

[rwilson]

I just assembled a 440 based 493 using trick flow 270’s and the Indy dual plane intake. My particular intake was cast really nice, only needed minor gasket matching and will just barely clear the hood on my 71 demon with a drop base air cleaner.

In regard to your camshaft, I would look for something with a little more duration at .050 if you plan on spinning it over 6000 RPM. My “streetable” solid flat tappet comes in at 275 at .050. and is spec’d for shift points just over 6000 RPM.

View attachment 1716460779

View attachment 1716460780

I’ve been looking for one of those Indy dual plane manifolds for a while

 

[AndyF]

I don't think I'd use the Indy DP intake with 512 cubes, especially if you're looking for any top end power. You have a lot of parts on hand and you're talking about buying a bunch more parts so I'm a little confused on what the plan is.
You could build a really stout street engine using your TF240 heads and the new 512 shortblock but maybe you want to sell your existing engine complete? I don't think the TF270 heads are required for a street car since they only add power up top and you'll very rarely be at WOT on the street.
I ran a low deck 512 with standard port heads in my Duster and it would pin your ears back. That engine used a heavily ported Wilson intake with port injection.
My Coronet has a 499 inch RB with TF240 heads and a TF intake with a Sniper throttle body injection. It pins your ears back too. Both engines made more than 600/600 with big flat torque curves.
You have to be very careful with your cam selection when you have a manual transmission. Especially with an overdrive transmission and street driving. You can't run a big cam down the freeway in overdrive. It just doesn't work. Once you selected the TKX transmission you made your cam choice. Remember, the TKX is only rated for 600 ft-lbs of torque and a 512 pump gas engine with TF240 heads will easily top 600 ft-lbs.

 

[rwilson]

I’m interested in the Indy two plane if anyone has one for sale

 

[autoxcuda]

I don't think I'd use the Indy DP intake with 512 cubes, especially if you're looking for any top end power. You have a lot of parts on hand and you're talking about buying a bunch more parts so I'm a little confused on what the plan is.
You could build a really stout street engine using your TF240 heads and the new 512 shortblock but maybe you want to sell your existing engine complete? I don't think the TF270 heads are required for a street car since they only add power up top and you'll very rarely be at WOT on the street.
I ran a low deck 512 with standard port heads in my Duster and it would pin your ears back. That engine used a heavily ported Wilson intake with port injection.
My Coronet has a 499 inch RB with TF240 heads and a TF intake with a Sniper throttle body injection. It pins your ears back too. Both engines made more than 600/600 with big flat torque curves.
You have to be very careful with your cam selection when you have a manual transmission. Especially with an overdrive transmission and street driving. You can't run a big cam down the freeway in overdrive. It just doesn't work. Once you selected the TKX transmission you made your cam choice. Remember, the TKX is only rated for 600 ft-lbs of torque and a 512 pump gas engine with TF240 heads will easily top 600 ft-lbs.

View attachment 1716463143

View attachment 1716463144

Would a single plane intake trade-off some torque to help the trans live and add some power at higher rpm’s when he wants to race hellcats?

With an overdrive Tremec trans what is the ballpark for cam spec boundaries on a 470-528 stroker?

 

[496 polara]

I’m interested in the Indy two plane if anyone has one for sale

Hard to come by. One popped up last week on eBay and ended up going for North of $500.

 

[rikkitik]

Would a single plane intake trade-off some torque to help the trans live and add some power at higher rpm’s when he wants to race hellcats?

With an overdrive Tremec trans what is the ballpark for cam spec boundaries on a 470-528 stroker?

Actually, a single plane would "potentially" move the the torque higher (in rpm and level), and right into the "shift point" range. If the DP is the "cork" that some are making it out to be, I should be plenty "safe". ;-)
As pertains to cam limitations, you would really like a cam that "smooths out" about 750-1000 rpm below your anticipated cruise rpm.
The trans I picked is only .81 in 5th, so I'm just under 2400rpm at 70 (available OD ratios are .68, .72, .81). But you would probably be safe as long as you hold overlap around 70 degrees or less (depending on cu in).
If you want to be completely "safe" power-wise, American Powertrain can upgrade the TKX to 900lb ft capacity.
Plenty of people running standard TKX's (street/strip applications) in the 650-700lb ft range without issue though. Roll the dice as you see fit.
In my case, I'm not planning on running anything stickier the DR's so "available traction" is kind of my "fusible link".