What do you think of my build? 318/390

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mini

mini

Small Bore Long Stroke
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Hey guys, halfway done my 318/390 build.
-69 318 block .030 decked .010
-69 894 X Heads 2.02 1.60 3 angle, Bowl Ported and Gasket matched milled .035" 60cc's
-Scat 9000 4.00 Crank
-Scat I beam 4340 arp 2000
-ICON -23cc Pistons 1.465"
-Comp 282S Solid lifter
-RPM Airgap Gasket Matched
-750cfm AED
Roughly 9.7:1

Any Horsepower guesses once I get it together and dynoed?
 
Sounds like a fun build. My dyno program is old and won't run on Windows 7 but I would guess 400 hp/430 tq. Keep us posted when you have it done. tmm
 
Nice cam for top end, with stroker monster torque at the bottom.
It would be wise to put a single plane intake on top, and with headers, I would guess.....

420 / 435
 
With that 4" stroke, you could actually run a little more cam if you wanted to...unless you have a very efficient exhaust, you may want to consider something in a split pattern...Maybe a Comp XE solid?

JMO though...depends on how much rumpity rump you can live with.

Also use the search function and go through some of the other 390 builds on here...I think it's "rnaz" running a 390 pushing 11s in a plum crazy Dart, I think...sucker sounds damn good though

You should be good for 400/425 though
 
mini said:
Hey guys, halfway done my 318/390 build.
-69 318 block .030 decked .010
-69 894 X Heads 2.02 1.60 3 angle, Bowl Ported and Gasket matched milled .035" 60cc's
-Scat 9000 4.00 Crank
-Scat I beam 4340 arp 2000
-ICON -23cc Pistons 1.465"
-Comp 282S Solid lifter
-RPM Airgap Gasket Matched
-750cfm AED
Roughly 9.7:1

Any Horsepower guesses once I get it together and dynoed?
Click to expand...

I had planned to build almost the exact same engine in a 69 Barracuda.
- 70 318 block .030 decked .010
-596 heads SS Ferrea 2.02 1.60 3 angle, Bowl Ported and Gasket matched 69cc's
-Scat 9000 4.00 Crank (I'll probably go with the cast crank)
-Scat I beam 4340 arp 2000 (I'm using SIR rods)
-ICON -23cc Pistons 1.465" (I'll use these pistons if I can get the Comp Ratio I'm looking for)
- Cam unknown
-RPM Airgap Gasket Matched
-750cfm AED
- adjustable iron rockers
- 340 drivers manifold and 2 1/4" magnum passenger's exhaust manifold with 2 1/2 pipes.
I have all the parts except the crank, cam and pistons. I wanted to run pump gas so 9.2:1 comp ratio (69cc heads).
I've also already installed a modified 2004R transmission w/1800 stall, running 3:08s but have a new set of 4:10s ready to install. I was shooting for 350-375 HP and looking for high torque engine with nothing over 5800 RPM. I shouldn't need any high RPMs with the overdrive!!

You didn't state what head gasket you planned on using??
Treblig
 

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Good old trusty felpro 1008. 039 thick 4.180 di. This is also going in a 3200lb 87 Dakota. 727 with 2600stall and 3.23.

As for the cam, it has already been purchased so for the next few years i will run it. And maybe upgrade in the future. I do like the XE grinds but I wanted to keep at .500 lift with a duration adequate enough to feed the stroker. 236 should do the trick.
 
Treb, with those chambers at 69cc you will actually be looking at more like 8.7:1. Get them milled .030 and you will be more like 62.75cc and 9.26:1
 
mini said:
Treb, with those chambers at 69cc you will actually be looking at more like 8.7:1. Get them milled .030 and you will be more like 62.75cc and 9.26:1
Click to expand...

Couldn't I just used taller pistons and a thin gasket to keep from cutting the heads?? I have to buy pistons and a head gasket anyway. I'm not worried about quench because of the stroke volume. I also read that stroke volume also increased the CR??

Treblig
 
mini said:
https://www.uempistons.com/index.php?main_page=product_piston_info&cPath=8_9_13&products_id=262
This will give you roughly 10.8:1 with 69cc chambers which is a little much.
Click to expand...

Yea, I think 9.5:1 is probably the max I should go. I don't think there's a thick enough gasket to bring those pistons down to 9.5:1. Well, if I have to cut the heads then there may be no other way (although I could swap out the heads for some 360s with a smaller cc, if they make any). If I cut the heads I imagine I'll also have to cut the intake side as well. But at least I already have the adjustable rockers. You didn't put that in your list of parts, I've heard you need adj rockers if you cut the heads.

treblig
 
mini said:
Diamond has a -16.7cc Piston. which will net you 9.5:1
Click to expand...

Boy, that would be nice. I'll go to the website and check them out!!! What gasket thickness would be required for 9.5:1 CR with those pistons?? Thanks,

PS - I'm far from an expert when it comes to the CR and volumetric efficiency and stuff like that. I know just enough to get in trouble!!LOL Does the -16.7cc piston mean that the piston is dished so that it has 16.7 cc below the deck surface??
treblig
 
Okay so,
3.94" Bore
4" Stroke
6.123 Rods
1.457 Compression Height Diamond Pistons -16.7cc Dish
= 9.58"
Felpro 1008 .039thick 4.180"dia = 8.76cc
69cc Chambers
.010 below deck roughly = 9.28:1 Comp
Now Dynamic Compression you need your Cam spec card
http://www.wallaceracing.com/dynamic-cr.php
 
mini said:
Okay so,
3.94" Bore
4" Stroke
6.123 Rods
1.457 Compression Height Diamond Pistons -16.7cc Dish
= 9.58"
Felpro 1008 .039thick 4.180"dia = 8.76cc
69cc Chambers
.010 below deck roughly = 9.28:1 Comp
Now Dynamic Compression you need your Cam spec card
http://www.wallaceracing.com/dynamic-cr.php
Click to expand...

What made you change your mind on the piston height and dish??? Did you decide not to mill your heads??

Treblig
 
mini said:
Updated ;). Using an Airgap. Love those intakes to 6500
Click to expand...

Probably looking at about 400-420 hp. The Airgap intake is a good choice, but with the cam and heads combo (and longer stroke) you will probably max out on power well below 6000RPM...depending on the heads, 5500-5700 ish.
 
mini said:
This is your motor treb! Lol my recommendation
Click to expand...

Ok, Great!! I thought for a minute you coming over to the "dark side" (lower CR). With a -16.7cc disc I can say that I have a reverse (up side down) HEMI LOL!! I appreciate all the help and research. 4.180" dia. gasket...that a pretty big hole over the piston. Won't the dead space create an area for pre-detonation or pre-ignition??? Or should I not worry about it?? As for the heads, I haven't had time to check the actual CCs on them. I have the equipment for CCing but just haven't had time. According to the Small Block Mopar Engines book they should be between 66-72.5 CCs.

thanks,

Treblig
 
No don't have to worry about the extra space.

I figured the cam would be my limit. But I'm okay with that. If I do upgrade my cam I will have to up my converter. These heads had a lot of short turn work. I believe they were flow benched at 265cfm @ .500.
 
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