Going to Build 470 Street/Strip Engine for 71 Demon

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J.V

J.V

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Joined
May 19, 2016
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Finland
Hey, Greetings from Finland!
Im going to Build 470 for my 71 Demon Street & Strip car. My current plans for engine is:

-77 Year 400 block bored to 4.375 and decked to 9.975 deck height. Aluminium main caps.
-Molnar 3.900 stroker Crank.
-Molnar 6.700 BBC rods.
-Diamond Pistons 1.32 CH with -12cc Dish.
-Trickflow 240 heads with 1.6 Harland Sharp Roller Rockers.
-Weiand tunnel ram intake.
-Mechanical Roller cam?

Does this setup sound good for you?
 
Looks like you're using high quality components! The tunnel ram, carbs, and cam are the tough part. I have no experience there. Maybe someone will chime in to give you some direction. 65'
 
J.V said:
Hey, Greetings from Finland!
Im going to Build 470 for my 71 Demon Street & Strip car. My current plans for engine is:

-77 Year 400 block bored to 4.375 and decked to 9.975 deck height. Aluminium main caps.
-Molnar 3.900 stroker Crank.
-Molnar 6.700 BBC rods.
-Diamond Pistons 1.32 CH with -12cc Dish.
-Trickflow 240 heads with 1.6 Harland Sharp Roller Rockers.
-Weiand tunnel ram intake.
-Mechanical Roller cam?

Does this setup sound good for you?
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Why not Trick Flow 270's? It looks like you are going to rev that baby up. I would talk to Dwayne Porter for the heads and cam, Wilson for the Intake porting and Mike at B3 racing for the rocker arm set up. The 3 of these folks can do some amazing things to parts and help you zero in on the combination.

MPFI would be sweet too, with either Holley HP or Dominator system depending on how many features you are going to run. Add a stout overdrive transmission with the right high stall, lock-up torque converter and it would really make the car a true street strip machine.
 
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.
 
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That engine sounds great! I ordered Molnar 3.9 stoke crank and 6.7 length rods from Cambell Enterprises today. I have to get my block to machinist to make bores clean before i order pistons to make sure what size pistons i can use and finish bore after i get pistons.
 
Can you recommend any list cams for me or should i ask custom grinds right away? Im looking for 10 sec times in 1/4 mile with full interior car in full street wear.
 
J.V said:
Can you recommend any list cams for me or should i ask custom grinds right away? Im looking for 10 sec times in 1/4 mile with full interior car in full street wear.
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JV, what I would do is start a new thread titled what cam do I select and state your engine block and goals. You will be amazed at the feeding frenzy of responses you will get! Hah! Seriously that question is almost as good as how do I degree my cam. The opinions are a bit varied with many folks illustrating their personal bias but you will get some seriously good suggestions. And a wealth of info from some very knowledgeable folks.
 
J.V said:
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.
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Indy's tunnel ram manifold for the 400 B-engine will go out to Max Wedge size. Part #400-14-15. The carburetor top is extra and available for 2x4150s or 2x4500s.
 
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Rear gear ratio and tire size and converter will be questions that the person who will be talking too about a cam is going to ask you, my vote is for PRH Dwayne Porter he's a member on here and also the 1 who picked mine post #6
 
Nearly exactly the same engine I'm in process of building except compression ratio & the tunnel ram since ill be building my own, the 240's will do you fine. Andy F built exactly what you & I and many have built he pulled 750 horses out of his & maybe got another 35-45 horsepower with the 270's.
 
I have been busy lately but now i start to get rest parts for engine. I was thinking that should i go for 240 trickflow heads or 270? With 270s i have to buy indy tunnel ram. I was also thinking that 240 with little porting could be good for 470 engine. Can somebody recommend me to someone who could make heads, intake for me?
 
J.V said:
Hey, Greetings from Finland!
Im going to Build 470 for my 71 Demon Street & Strip car. My current plans for engine is:

-77 Year 400 block bored to 4.375 and decked to 9.975 deck height. Aluminium main caps.
-Molnar 3.900 stroker Crank.
-Molnar 6.700 BBC rods.
-Diamond Pistons 1.32 CH with -12cc Dish.
-Trickflow 240 heads with 1.6 Harland Sharp Roller Rockers.
-Weiand tunnel ram intake.
-Mechanical Roller cam?

Does this setup sound good for you?
Click to expand...
Update on my last post.
I run the same stuff. Milled my 240s to 65 cc
Welded and ported my tunnel ram.
Solid flat tappet 264-268 .
Made peak power @ 5800
Had over 600 ft lbs down a 2900 rpm.
My combo made 685 hp and 665 tq.
I am going to port my heads out to the bigger Hughes gasket 2.625 height port vs the 2.375.
Also am buying parts to use a mechanical roller 272-284 .700 lift.
That's going to be a good combo.
 
J.V said:
I have been busy lately but now i start to get rest parts for engine. I was thinking that should i go for 240 trickflow heads or 270? With 270s i have to buy indy tunnel ram. I was also thinking that 240 with little porting could be good for 470 engine. Can somebody recommend me to someone who could make heads, intake for me?
Click to expand...
@PRH
 
I ordered 240 heads today i guess i will try those with out porting at first. Now i try to choose Pistons i have been thinking between 3 different Pistons currently, Mahle PowerPak, Diamond racing and Icon. Mahle and Diamond are 4032 alloy and Icons 2618. With Mahle comperssion ratio is about 11:1 and with Diamond and Icons its about 10.6:1. I looking to make quite bad *** street engine that sees some strip too. I guess best choice is solid roller cam and looking for about 650 horses atleast. I just dont know how close to limit those 4032 alloy pistons are with that kind of engine? I know heads getting close to limit but i guess that is possible with right cam?
 
J.V said:
I ordered 240 heads today i guess i will try those with out porting at first. Now i try to choose Pistons i have been thinking between 3 different Pistons currently, Mahle PowerPak, Diamond racing and Icon. Mahle and Diamond are 4032 alloy and Icons 2618. With Mahle comperssion ratio is about 11:1 and with Diamond and Icons its about 10.6:1. I looking to make quite bad *** street engine that sees some strip too. I guess best choice is solid roller cam and looking for about 650 horses atleast. I just dont know how close to limit those 4032 alloy pistons are with that kind of engine? I know heads getting close to limit but i guess that is possible with right cam?
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I run 4032 , in about a month it should be pushing well over 700 hp.
You'd have been better off with the 270s but the 240s will do fine and there's room to port them.
 
Mahle Pistons seems quite interesting as those are quite light! But i havent heard much about those how good those are in combination like this. For example how well those valve pockets are designed for higher lift cams with zero deck? I heard that 4032 alloy is used even in Pro stock engine pistons so definetly those can handle serious power when its made right and when using top quality parts and spot on tune.
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Have you checked out Ross pistons,
That's what I have in my 470 motor
 
I use srp pistons, je pistons affordable line of pistons lol
 
67mprfan said:
Have you checked out Ross pistons,
That's what I have in my 470 motor
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I have checked Ross but looks like self models rise comperssion too much for pump gas as those are just 4cc dish. I have 6.700 Rods so pistons should be 1.32 comp height and about 8-12cc dish to keep comp around 10.5 - 11. Bore will be 4.375.
 
J.V said:
I have checked Ross but looks like self models rise comperssion too much for pump gas as those are just 4cc dish. I have 6.700 Rods so pistons should be 1.32 comp height and about 8-12cc dish to keep comp around 10.5 - 11. Bore will be 4.375.
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What's your pump gas in Finland.
People run 93 octane up in the 12.s for compression
 
MOPARMAGA said:
What's your pump gas in Finland.
People run 93 octane up in the 12.s for compression
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Its 98 Ron, some chart did show that it should be quite equal to 93 US octane. I have heard that some have ran high 11s comps with out any knocking issues but most street engines are made to run between 10-11 to keep it safe.
 
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