Looks like I need to quit throwing money at my GM sbc 400 block. It has done treachery second build in a row on #4 main cap to register fit, and I don't trust it any more. And boy that hurts my feelings pretty bad because I sure loved that engine. It made me happier than any other engine I've owned and I just am having trouble saying goodbye to it. I guess I'll get over it.


I don't trust it any more. Fixing it again is option 1.

I have another 4 bolted 400 block but it is .040, I have Ross 15:1 pistons for it (not in hand and not sure of their compression height) but no rods or crank. My current engine is .030. If my Ross .040 pistons are the same compression height as my JE .030's...I could put my Childs rods on them and rebalance with my 3.80 crank. That is option 2. And something tells me I would run into a costly SNAFU.

Find another 400, 4 bolt it and take it to .030 is Option 3.

All these options cost, and take me to Option 4. New Dart Little M with billet caps 4 bolted on all but #5 and 1/2" bolts on #5. Talking to Carl and Mike about deck heights I realized that my little 3.8 stroke crank needs 9.015 deck whereas most strokers need 9 even. I don't like the idea of buying a new block at 9.015 so I can run my 3.8" crank...and having to re-deck when I eventually go to a 3.875 stroke.......................................
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I just pulled the trigger on a new Dart block from Carl Hinkson and a new rotating assembly from Mike Lewis.

We're talkin 421 baby
Callies Magnum knife edge crank
Compstar rods(I'll let you know what I think on them after I see em) Mike says they are good
My choice of top of the line pistons
With rings and bearings, all balanced by Mike

And a Dart Little M block at 9.000 all CNC'd by Carl, no more weak block woes

So, only 2 or 3 things yet to decide
Compression ratio
Cam

What's yalls thoughts on compression ratio vs power gain?

Here's the goal. Can flat-tops and pump gas do it? 14:1?
Sub 10 second naturally aspirated small block
Sub 9 second juiced, on the same cam

14:1 is kinda alot for power adders,no???sounds like you`re lookin for a real scorcher,tho tim...love to hear how it turns out...(hey, meybe now would be a good time for turbo stuff to fill your garage...lmao...)

Running 14 or 14.5:1 with nitrous is no problem with good fuel. I know some guys running almost 16:1 with nitrous.

I know taking a 8.5:1(?) 76cc headed 383 motor (with way too much cam I was 16) and only changing the heads to alum 54cc and making it an 11.1 made that thing an animal.
Pump gas in a 70 Nova. Then we swapped that for a BBC and it went slower.
Had some help but did a aftermarket 400 block and a custom crank and got 420 out of it. It was around 14.1. It was 680hp to the wheels IIRC.

14:1 is too much for todays pump swill imo...add nitrous to that, and you have a great recipe for piston gravy...tims post stated pump swill...i can see running 120 octane with nos, and a timing retard device at 14:1, but not on 93...jm2c...

You know me, say so damn much my meaning gets lost.
I suck at brevity, sorry guys. I try to say things short but I suck at it. Oh wel

It's a question, can I do it with flat tops, or should I blow that off and go with what 13:1, 14:1.... Idunno so I'm asking y'alls experience and knowledge

get ballsy Tim! Do it with flat-tops.

i`d prolly pose that question to carl...(but forged flat tops would prolly get the job done imo)i wouldnt really go much over 12.5 or 13:1 if you plan on running pump gas...and keep your tune sharp at that comp...course, if you got a cam2 station in the area, you could cut the fuel, but that becomes a royal pita...great heads are the key to great power imo...we run afr`s on the little 383 that could, and they`re awesome...

Sure be less finnicky, but Idunno if flat tops will take me into the 9's NA.

Goferit Tim, you did the right thing. I dont think you are building a street motor? Naw , not you. For a race motor , I would stick with 13-14:1, get the biggest slug that you can fit in the head, biggest head and go play. You will have a strong bottom end and block. The rest comes natural. Now all of this IF you are running a race motor and dont mind buying bbls of fuel. Only go around once.
I am using the Compstar rods, I am impressed along with the profiled Scat crank. Last gas motor I had , I used Ross 13.1 piston, Howards alloy rods and heads angle cut .100 on exhaust side. Really filled up the chamber.

What's a cam2 station? Is it like a noid light?(inside joke)
I live in BFE Oklahoma and I'm a damn hick, I have to load wolf and drive 3 hours to get to a track. I figger if I go high CR I will bring home 10 or 20 gallons each trip to Oklahoma City if I need some. That's not a problem, just a PITA and potential loss... I hear the stuff goes south pretty fast. I can see me outside spraying ant beds and weeds with dead race gas mixed with oil....sheesh

I have Brodix T-1 CNC 227 heads.

Your little 383 that could... tell me more Mike.

Hi Don
Got me pegged eh?

nawwww, no mild mannered mouse here.
We gunna build a fire breathin bahstuhd


And I'm definitely leaning to the 14:1 unless somebody says yeah hey old so snd so has an NA SBC running 9's with flat tops
I can hear it and feel it already guys

ya, show'um what old knows and does.

Whats the saying, "just because there is snow on the roof , there's no fire in the furnace"

In my opinion the more the better, but I LOVE high compression motors and wouldn't mind dishing the dough for 100+ octane.
The reher-morrison motors with 16.5:1 can run 350 shot of juice and are fine.... But that is a TON of money in those things, but from what you listed (parts and block wise) I believe your motor could handle 14:1+ with a good sized (120-150) shot of juice.
I would do 14:1 if I were you.
I don't know, I know as much as the next guy i guess...

I see 230+ cc heads,.670+lift/280 or so @.050 SR cam,12:1's, and a 5000 stall spinning 4.56's to say 8000ish. maybe more ??????

Good luck.