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Old 03-18-2014, 01:49 PM   #1
vettezobsezzed
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Default 400 ci

Ok, no more wanting to do this, I'm ready. But the more I learn, the more it seems I don't know.

This is what I have.

400 sbc bored 0.060. Stock bottom end, but new.
I have no intentions of tearing into the bottom end. This build only has about 10k miles on it, and ran fine.

I got a line on some AFR 195 w/65cc chambers, below cost. So I'm dying to cash this in, and not let it pass.

So I pulled the heads and intake, and cleaned it up a bit. This is where I'm losing. Verified tdc. Pistons are 0.2o in hole. Ok. Take syringe and fill each cyl at tdc, all about 19-21 cc to fill, first time, so not to scientific. Check out summit for head gaskets, smallest I can find In a 4.2 bore, is 0.21. So I punch it all into jeep stroker calculator, this is the result



So, from what I've gathered, this is a no go with over 11:1 comp, and exceeding 8.5:1 dcr.

Hoping you guys can help me here. I'd hate to let these heads pass me by. Can this be pulled off without a whole bunch of specialty mods.

Car is 1979 vette, th350, 3.55:1 rear. Not for daily driving, not for track use either, I usually average 1500 miles a year, and I like to think its all spirited driving.

Defiantly open to hyd roller cam, have zero interest in trying to spin to7000 rpm. I. Want to "haul" from idle, hwy cruise is 3000 rpm

Budget should be restrained to $3k, but negotiable. Heads will be 1/2of that of course.

First things first, Is any of this even reasonable, or am I right out of it.

Thanks.
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Old 03-18-2014, 02:07 PM   #2
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Use a thicker head gasket.
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Old 03-18-2014, 02:10 PM   #3
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You can't use 65cc heads on a .060-over 400 and get a streetable comp ratio. You have to use the 72 or 75 cc heads on that engine. You're also not going to have a .021 head gasket - gasket will be in the .040-range, but this still doesn't get you where you need to be.
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Old 03-18-2014, 03:16 PM   #4
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Quote:
Originally Posted by lars View Post
You can't use 65cc heads on a .060-over 400 and get a streetable comp ratio. You have to use the 72 or 75 cc heads on that engine. You're also not going to have a .021 head gasket - gasket will be in the .040-range, but this still doesn't get you where you need to be.
I agree 100%. I have a dart shp 400 with 72cc pro-filer 210 heads and
cometic .027 mls gaskets.The .027 gaskets are the thinnest I could find.
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Old 03-18-2014, 03:39 PM   #5
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Run this in your calculator.
http://www.summitracing.com/parts/hr...make/chevrolet

http://www.summitracing.com/parts/fe...make/chevrolet

Will need a 2400 stall convertor. Drop actual operating range about 500 RPM for a 400 vs the listed operating range for a 350. Cam has a 4 degree advance ground in. Figure your altitude. Can you get 93 octane? You can back timing down to 32-34 all in with AFR heads and run a 160 degree thermostat, that will help. You will be @ .060 quench which isn't the end of the world.
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Old 03-18-2014, 04:47 PM   #6
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I'd actually abandoned searching for a cam until I figured if this would work. That 280 in the calculator gave me the lowest dcr, so that's why I posted it.

I know it really draws ire when people say "for the next build" but really this is what the 64cc heads would be for. This block and crank aren't top notch big money pieces, but they are still quite useable. This engine is a toy I never really got to use as much as I wanted.

Really was hoping this plan I had would work, to keep my car on the road while i got a sweet 350 together. At which time could throw those heads onit.

Good fuel here is 91 octane, I'm not gonna get into mixing fuel. Lawn mowers and chainsaws are enough for me.

As for changing torque converter, certainly do able and I'm open to that idea.

But I'm just not sure I have the expertise, or know how to get into custom cams, and special tuning. I have successfully assembled carbs, and engines and such, but have never really pinned down the science, more just did it like jigsaw puzzles.
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Old 03-18-2014, 04:55 PM   #7
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Best to pass on the heads. 72 -76 cc would be a lot better.
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Old 03-18-2014, 05:15 PM   #8
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400 small blocks cam with dished pistons. You have flat top with only 2 valve reliefs. You will have extremely hi compression with 64cc heads. Also you have to see how far down in the hole those pistons sit at TDC. It is critical to have this measurement so you can pick the correct heads and gaskets!
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Old 03-18-2014, 06:37 PM   #9
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can a 400'' block be bored out to .060'' safely?
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Old 03-18-2014, 06:38 PM   #10
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I ran this before my last post, but couldn't get it to here till now.

The numbers are better, but I'm not really interested in the power at high rpm, I get zero track time. I need it as low as possible.

With 10.6 static and 7.8 dcr, is it realistic. Or would I not make power until 2k rpm.

No doubt I can get the other heads, just gonna cost more.


What about my quench tho, how much is this hurting me? I've only ever read that you want .35>.40. I guess it's irrelevant unless I completely tear down and start over.
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Old 03-18-2014, 06:46 PM   #11
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I guess the other optionis put the old 882 back on and just run it pfft what fun is that. Redirect funds to side pipes and wheels (factory originals of course). Or just leave the l48 alone and just put put around.
Times running out on me, my season is so short...

I was supposed to meet up with the guy with the heads yesterday, but life got in the way and. It didn't happen, good thing, gave me time to come to you guys.
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Old 03-18-2014, 06:54 PM   #12
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Quote:
Originally Posted by 76strokervette View Post
I agree 100%. I have a dart shp 400 with 72cc pro-filer 210 heads and
cometic .027 mls gaskets.The .027 gaskets are the thinnest I could find.
I followed your build, it was the first I'd seen of profiler heads, but they didn't reply to my emails about shipping costs, and any 3rd party brokers I want to, there was extensive wait times, and pricing was up to within $300 of afrs. So again it was kind of a wash. Been patient for a year now with this engine, but I don't know... The snows melting and I'm getting anxious to do something.

Ever since I bought this car and started on this forum, I get all these theory's and ideas, and just when I think I got her dialled in, there's. something else I didn't know. It always feels likes chasing my tail lol.
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Old 03-18-2014, 06:58 PM   #13
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Quote:
Originally Posted by bluedawg View Post
can a 400'' block be bored out to .060'' safely?
Lol, too late, we're already here. I'm not to sure on the safety of it, which is the biggest reason I'm not interested in going further with the short block, just top end kit. Checkers or wreckers!
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Old 03-18-2014, 09:31 PM   #14
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Quote:
Originally Posted by vettezobsezzed View Post


I ran this before my last post, but couldn't get it to here till now.

The numbers are better, but I'm not really interested in the power at high rpm, I get zero track time. I need it as low as possible.

With 10.6 static and 7.8 dcr, is it realistic. Or would I not make power until 2k rpm.

No doubt I can get the other heads, just gonna cost more.


What about my quench tho, how much is this hurting me? I've only ever read that you want .35>.40. I guess it's irrelevant unless I completely tear down and start over.
it looks like a big cam but 412 CI tames a cam down big time. With a 2400 stall and 355 gears I think it will work fine. It should be in the operating range of the cam from about 1900 to 6000 but it will pull below that. It depends on your driving style. A 412 with AFR heads and that cam duration and lift will make over 500 HP and a lot of torque, even below the cams range. The 195 heads will help with bottom end as will the 112 LSA. If you take off from idle and floor it your convertor will let it spool up some. Midrange from 3000 to 5000 will be a beast. Stock quench is .060. Ideal is .040. The AFR heads will fill the cylinders well so take the 7.8 DCR with a grain of salt. If you want a milder build you go with bigger chambers and a smaller cam. Either way a performance timing curve, the proper vacuum can and careful carb tuning will get the most out of the combo.
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Old 03-18-2014, 09:47 PM   #15
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Mako, those were all the words I wanted to hear... Beast... 500hp. This Is what I'd hoped for when this fever came over me the first time. I've studied up on all the Lars papers, and practiced the timing curve adjustments on my car and old dump truck, both with noticeable improvement. How good I did is yet to be proven, just because both are old and tired. Question myself all the time, is it to much, not enough, could I have done better, until ya just call er good and put it bac together.

Already on my bench for this build are a performer rpm intake, n.i.b Mallory hei distributor, edelbrock 1407 carb, I'm ready to go for it.

I just get so caught up in numbers, when the calculator spit out numbers I didn't like... Just gets me scared to go for it.
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Old 03-18-2014, 11:12 PM   #16
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Are you sure about the 19cc's volume. Seal the piston top with grease and all?
If you are.020 down the hole then that is .27497 cubic inches of volume.
Using an online calculator that comes out to 4.5 cc's of volume.
So any thing more than that is piston top volume.
Given that and your measurement of 19 cc's your piston volume is 14.5 cc's.
At least that is what I come up with. Check my math as I made have made an error in the calculations.

Be absolutely sure of your volume measurements an your math before choosing the cam for you CR.

With your 280 duration, 109 LSA, and .021 gasket that comes out to
10.52 CR and 8.43 DCR.

At 2200 feet it comes out to 10.08 and 7.99 respectively.
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Old 03-18-2014, 11:25 PM   #17
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Quote:
Originally Posted by REELAV8R View Post
Are you sure about the 19cc's volume. Seal the piston top with grease and all?
If you are.020 down the hole then that is .27497 cubic inches of volume.
Using an online calculator that comes out to 4.5 cc's of volume.
So any thing more than that is piston top volume.
Given that and your measurement of 19 cc's your piston volume is 14.5 cc's.
At least that is what I come up with. Check my math as I made have made an error in the calculations.

Be absolutely sure of your volume measurements an your math before choosing the cam for you CR.

With your 280 duration, 109 LSA, and .021 gasket that comes out to
10.52 CR and 8.43 DCR.

At 2200 feet it comes out to 10.08 and 7.99 respectively.
Well, I tried to be as accurate as possible, levelled off block, best I could, each time, did my best each time to verify tdc on each cylinder. I didn't seal off with grease. And I used diesel instead of water. But with there controls in place, it's what I got, this # includes the valve relief too. Like I said, first timer for these measurements. Trying my best to put all info req'd on the table.
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Old 03-18-2014, 11:30 PM   #18
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I kinda didn't know how to apply this measurement to any calculator. It's actually what I thought would save me and make the 65cc chamber an option.
But, lacking confidence and expertise, I brought it to the forum. I just couldn't spend the cash without a little confidence boost from someone besides they guy selling. For all I know, he's looking at the same situation I am... Lol.
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Old 03-18-2014, 11:37 PM   #19
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I punched your math, and I believe u are correct, I'm just not sure how to apply it to the dcr calc to get your result. But, I like your final result, you'll have to show me how you got to it.

Last edited by vettezobsezzed; 03-18-2014 at 11:41 PM.
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Old 03-19-2014, 06:38 AM   #20
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Mill the heads, replace what's necessary on the fuel system and run E85. It'll run cool and clean.
Or do y'all even have it in the Great White North?
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Old 03-19-2014, 06:38 AM
 
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