512 stroker build, need suggestions

I just finished a 512 stroked 440 for a friend and it runs smooth with lots of power, He kept my budget tight.. I used a 440 Source stroker kit their Comp cam with 525 lift 440 source stealth heads ( wanted to use indy''s but not in the budget) new stamped steel rocker arms, Sam at TTI suggested 1 7/8 headers with a 3 inch exhaust, Holley 850 w/ vacuum secondaries and a Holley street dominator intake that WILL clear a stock 68 Satellite hood. I have built a bunch of strokers This combo really works well and is super streetable on pump gas

I used Ohio Crank for my 440 based 499. Comp ratios were a problem for me, too. Talked to Ohio Crank about it and they calculated the amount the pistons would need to be milled and milled them for under $100.

If I use re -17cc pistons it gives me a compression ratio of 10.6 and dynamic of 8.9, doesn't this sound too high for 91 octane? Spoke with 440 source and they said majority if people go with the 17cc kit. I'm trying to find some definite information on running 91 with this setup before I dish out the cash. The -27 gives more conservative numbers, CR of 10:1 and dynamic of 8.4:1 but yet the 440 source tech said not many people order this, why? I understand leaving power on the table but I'd rather have it somewhat mild, good street manners and super reliable.

80cc stealth heads
Lunati 60312 hydraulic roller
440 source 512 kit

It is common for people to choose too much carb and too much cam, so people choosing too much compression for the application would not be surprising. If you're concerned about detonation on your pump gas, then go with the lower C/R and build the quench. Your already using aluminum heads which will help.

Can someone calculate the difference in power between the 2 C/Rs? I'll bet it's not much.

And why isn't there more discussion about quench in this? Isn't it an important component in this combo?

Yea I agree, lower compression kit is better for my needs. All things being equal other than piston dome cc, how much of a power decrease will I see between 10.5:1 CR and 10:1 CR?

We all remember the .100 in the hole, low compression 440s of the late 70s. Some of them knocked on premium. Just plane bad combos.

Point being, that C/R is not the end-all, be-all when it comes to detonation. It is the whole package.

Awesome, thanks guys. Here's what the basics of my build is going to look like, what do you think?

-512 stroker (440 @ .055 over)
-27cc dish, 4.250 stroke, 7.100 rod
- Holley Street dominator Intake
- 850-950 carb
- 440 Source Stealth heads (80cc)
- Lunati 60312
.535/.550 lift, .231/.239@.050,.283/.290 advertised, 110 lobe sep, Rpm 2200-6200
- 1.5 comp pro magnum rockers

I've used that Holley intake on my 499. Worked good. With a little larger cam, I ran both the 850 and 950 carbs. I only changed the Holley intake out when I went with the Dominator. I actually converted the Holley to the Dominator for a while as a test. It worked okay, the car picked up a bit.

That is a relatively small cam for that engine. With 512" and mild heads, it certainly won't pull to 6,200. That range must be for a smaller inch engine.

I was between the lunati 60312 and 60313. My thinking was I'd rather undercam slightly than overcam. Want the low end power for the street as I doubt I'll be revving it that high. Here's the 60313, I thought it looked too big?

Lunati 60313
Duration: .294/.302
Duration @ .50: .243/.251
Lift: .560/.565
Lobe sep: 110
Rpm: 2600-6600

Is there a way to calculate duration based on a 512ci? What type of manners do you think the 60313 would have for a street only car?

I used these 440Source dished pistons in my 440 based 493 I built for my 63. But I used the Indy EZ head since I got a very good deal on them from Dwayne Porter and it was worth the extra few hundred to me as I was going to use Eddy RPM heads. But actually I was going to have the RPM's CNC'd and that added enough that the EZ heads I got from Dwayne ended up costing less as I just had Dwayne work my EZ heads some and they were cheaper then CNC'd RPM's as the CNC adds like 1k to the price. But the EZ heads are 75cc's and after I used these dished pistons that came out about .007 down in the cyl I was at about 10.0 so Dwayne cut the EZ heads to 70cc's as I came out at 10.6 comp right where I wanted with my setup as I run it on 92 pump. Dwayne Porter also speced me a solid flat tappet I run thats 264 & 270 @ .050 with .585 & .592 lift. Has a 110 LSA and I have it in on a 106 ICL. I told him I wanted a cam with some rump rump in the idle and I wanted to make some good power since I run on 92 pump and run it through the full exh system. But with EZ heads and at 10.6 comp and .046 quench it runs good on 92 pump as I have run 37 total timing all in by 1800 rpm with no ping at all. The intake valve closes at 58 degrees ABDC @ .050 and I do use Hughes 1.6 roller tip rockers for .624 and .632 actual lift. I use the Indy dual plane intake with an 850 Holley DP as its just the basic DP and nothing special. But it works nice for me as my 63 is mostly a driver as the last few years I have only got to the track once a year but I have it out every weekend from March to November weather permitting. My stroker kit is a 440Source kit with the 4.15 crank and the I beam .990 pin rods. It has been in my 63 since June 2011 and has not given me any problems at all. The piston pins were a little tight in the rods and I just sized the rod bushings a tad to get the fit I liked. Nothing else needed any major work as I did some touch up on some parts but nothing much as I have no complaints with the 440Source parts. I drive it to the track most of the time unless I go to a track real far from home then I try to have a tow lined up in case I break but its always driven home and has run 10.70's so far at just over 3700 lbs. My brother has used 440Source kits also with good luck and he also used a Muscle Motor kit in one of his engines with Icon pistons and an Eagle crank with no problems and good luck also. Thought the info might be useful for you to hear about. Anyway good luck with yours. Ron

We hadn't discussed camshafts yet. Just trying to be prepared and have a good idea of what I'd like.