Going to Build 470 Street/Strip Engine for 71 Demon

[cookietruck]

I think that mahle piston is 1.35” ch instead of 1.32
I think that puts it above deck with the 470 combo with 6.7 rods right?

 

[MOPARMAGA]

I think that mahle piston is 1.35” ch instead of 1.32
I think that puts it above deck with the 470 combo with 6.7 rods right?

That would be + .040 out of the deck in my 470.
My 1.320 pistons stick out + .010.
The math says the 1.320 should be .004 under but a squared up block might take a few extra thousandth to get .000 across the board.

 

[MOPARMAGA]

I was looking for 270s but i quess there are not many options for intakes for lowdeck with Max wedge port size? I know, Indy makes singleplanes but is there any tunnel rams? I assume that custom cam would be great choice specially with tunnel ram?

Drivetrain will be 727 transmission with reverse manual valvebody etc. + Dana 60 rear.

That's where your hot-rodding skills will be tested or made, making things work that aren't supposed to. The tunnel ram I have is just a wieand standard port, I welded the outside of the runners and ported it to a larger gasket size.
I'm now getting ready to do it again to a larger size port. The 270 port is still relatively small compared to a real max wedge.

 

[67/6barracuda]

How about the 440 source stuff specifically their forged pistons and rods. Seems reasonably priced? I’m asking cause I have a 400 block and the stroker crank already the 4.150” so 499ci I think it is. I’ll follow along see what you do.

 

[Carnut68]

How about the 440 source stuff specifically their forged pistons and rods. Seems reasonably priced? I’m asking cause I have a 400 block and the stroker crank already the 4.150” so 499ci I think it is. I’ll follow along see what you do.

440 source pistons are Icon.

 

[J.V]

I think that mahle piston is 1.35” ch instead of 1.32
I think that puts it above deck with the 470 combo with 6.7 rods right?

Atleast Mahle advertising their part number: 930274175 to be 1.32ch. If you have some other realiable info about those let me know. I dont want to order wrong parts. My best shot so far has been try to trust what manifacturer says but of course that could be typo.

How about the 440 source stuff specifically their forged pistons and rods. Seems reasonably priced? I’m asking cause I have a 400 block and the stroker crank already the 4.150” so 499ci I think it is. I’ll follow along see what you do.

I have heard good about 440 Source stuff. Those are used in really strong engines without problems. For street engine i prefer to choose piston that doesnt need support rails for oil ring.

 

[J.V]

That's where your hot-rodding skills will be tested or made, making things work that aren't supposed to. The tunnel ram I have is just a wieand standard port, I welded the outside of the runners and ported it to a larger gasket size.
I'm now getting ready to do it again to a larger size port. The 270 port is still relatively small compared to a real max wedge.

I have stantard port Weiand tunnel ram too, If i find that i need to get bigger ports i will get indy max wedge port tunnel ram or make one from aluminium sheet. I try first with standart port. I already matched top and bottom part and cleaned up runners and plenum. I personally dont find reason to thicken runners from that intake as it needs lots of argon and welding wire or rods and in here Finland those arent cheap and take lots of time. I find it easier to make that from sheet. Dont get me wrong, its cool that someone wants to go bit different route and try things! I still have atleast hundreds of hours to do in body work alone as i make all reinforcements and body work by my self. I also need to shorten up that dana, build that 727 etc. so i dont want to use too much time to work up intake alone.

 

[cookietruck]

Atleast Mahle advertising their part number: 930274175 to be 1.32ch. If you have some other realiable info about those let me know. I dont want to order wrong parts. My best shot so far has been try to trust what manifacturer says but of course that could be typo.

Oh sorry. Looks like they’ve added pistons to their catalog.
I thought you were looking at the 440 piston at 1.35ch and 4.375 bore.

They even have a 1.32 piston for 383 bores now. Pretty nice if 8.1cc dish works for people.

 

[MOPARMAGA]

I have stantard port Weiand tunnel ram too, If i find that i need to get bigger ports i will get indy max wedge port tunnel ram or make one from aluminium sheet. I try first with standart port. I already matched top and bottom part and cleaned up runners and plenum. I personally dont find reason to thicken runners from that intake as it needs lots of argon and welding wire or rods and in here Finland those arent cheap and take lots of time. I find it easier to make that from sheet. Dont get me wrong, its cool that someone wants to go bit different route and try things! I still have atleast hundreds of hours to do in body work alone as i make all reinforcements and body work by my self. I also need to shorten up that dana, build that 727 etc. so i dont want to use too much time to work up intake alone.

I used a 300 cf bottle of argon and 300 feet of rod. I only did it that way because I can't afford $1200 for an intake. When I go to a bigger tunnel ram I will build one.

 

[J.V]

Oh sorry. Looks like they’ve added pistons to their catalog.
I thought you were looking at the 440 piston at 1.35ch and 4.375 bore.

They even have a 1.32 piston for 383 bores now. Pretty nice if 8.1cc dish works for people.

Yeah, i accidentally found those by looking 1.32 CH 4.375 Bore Pistons from Summit. Atleast those seem quite nice pistons for price.

I used a 300 cf bottle of argon and 300 feet of rod. I only did it that way because I can't afford $1200 for an intake. When I go to a bigger tunnel ram I will build one.

Wow thats alot! Here 300cf argon bottle fill alone cost about 500$.

 

[J.V]

I have been thinking cam for that engine and Howards Cams 722323-08 and 721883-08 looks quite interesting grinds. Any experinces about those in street engine? I know custom grind would be best but i should find experienced grinder or mopar specialist to get recommendation for specs to my combo.

 

[MOPARMAGA]

Yeah, i accidentally found those by looking 1.32 CH 4.375 Bore Pistons from Summit. Atleast those seem quite nice pistons for price.

Wow thats alot! Here 300cf argon bottle fill alone cost about 500$.

Wow, holy crap. It's about $120 here.
It was about $600.00 to buy the bottle and gas.
I just kept stepping up in bottle size after I ran out. Luckily the 300 didn't cost me anything more than just the fill because they didn't have my smaller bottle which I think was 250cf

 

[MOPARMAGA]

I have been thinking cam for that engine and Howards Cams 722323-08 and 721883-08 looks quite interesting grinds. Any experinces about those in street engine? I know custom grind would be best but i should find experienced grinder or mopar specialist to get recommendation for specs to my combo.

@PRH for your custom grind.
I like the 1st cam listed, no experience with it though.

 

[autoxcuda]

@ns1rm21

 

[J.V]

Howards cams recommended 722103-08
Lift: .640 intake / .630 exhaust, Duration @ .050: 263 intake/ 275 exhaust, Centerline: 104, LSA: 108. Im still waiting recommendation from comp cams.

 

[1967 Cuda]

I was just reading through this thread and thought I would share some info on my 470 that I built last year.

• Eagle 3.91 Crank
• 6.760" Eagle Rods
• Ross 99496 Pistons
• Indy SR Heads (Ported by Indy - Flow 351 CFM Int and .233 Exh @ .606)
• Trickflow Hydraulic Roller Cam
  • .600 lift with 1.5 Rockers Int and Exh
  • Duration @ .050 243 Int/ 247 Exh
• Holley Street Dominator Intake (A lot of port work done to this intake)
• CR 11.2

Dyno Results: 658 HP @ 5300 and 689 TQ @ 4100
TQ is over 600 from 3000 all the way through 5500 (Dyno sheet attached)

This is a street/strip build going in my 68 Dart and the intake and cam probably limit max HP. A little more cam and a tunnel ram would most likely push it over 700 HP, but I wanted to keep the stock hood and had the cam. One thing that you will really want to focus on is getting a quality torque convertor for a street/strip build. I had Dynamic make a custom convertor for me based on the dyno specs, weight of car, tire size, etc.

Good luck with your build!

 

[J.V]

I was just reading through this thread and thought I would share some info on my 470 that I built last year.

• Eagle 3.91 Crank
• 6.760" Eagle Rods
• Ross 99496 Pistons
• Indy SR Heads (Ported by Indy - Flow 351 CFM Int and .233 Exh @ .606)
• Trickflow Hydraulic Roller Cam
  • .600 lift with 1.5 Rockers Int and Exh
  • Duration @ .050 243 Int/ 247 Exh
• Holley Street Dominator Intake (A lot of port work done to this intake)
• CR 11.2

Dyno Results: 658 HP @ 5300 and 689 TQ @ 4100
TQ is over 600 from 3000 all the way through 5500 (Dyno sheet attached)

This is a street/strip build going in my 68 Dart and the intake and cam probably limit max HP. A little more cam and a tunnel ram would most likely push it over 700 HP, but I wanted to keep the stock hood and had the cam. One thing that you will really want to focus on is getting a quality torque convertor for a street/strip build. I had Dynamic make a custom convertor for me based on the dyno specs, weight of car, tire size, etc.

Good luck with your build!

View attachment 1716344250

That is quite stout engine with quite mild cam! Really nice build!


I got new cam recommendation from Jones cams:
Cam#: D440, R76424-77424-110
255/259 @.050"
.424"/.424" Lobe Lift
.619"/.618" Net Valve Lift (after lash)
110 LSA

What you guys think about that? I think Mike uses inverse radius profiles. I dont know how much that makes difference but to me Jones and Howards cams seems quite different at durations. Lifts seems to be in same area. I also sent message to Racer Brown for cam recommendation.

 

[J.V]

I decided to go with Jones Cams custom grind and ordered BAM DLC coated steel on steel lifters too. Mike told that my combination with that cam should make +650 horses if engine is made right. I think that would be enought for me and should move Demon quite well.