82-92 V8 Tech V8 Camaro General Topics.

305 to 350 swap?

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  #51  
Old 05-13-2011, 03:10 PM
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Well, I had a talk with the owner of the shop that I intend to have do the actual swap- I would love to do it myself but my helper can't give me all of the time needed, and I don't have sufficient equipment to make it happen, unfortunately.

Anyway, he says to let him know about a week in advance once the motor's about ready and I can bring the car to him to get started- I'll also get my transmission rebuilt at the same time.

He did mention though that it sounded like I was making a lot of compression for street driving and that 94 octane probably wouldn't be enough for 12.75:1- I had previously had someone suggest double-stacked head gaskets to bring it down a bit, so I guess I will be doing that as well.

Just waitin' on the heads and cam, for the moment~
 
  #52  
Old 05-13-2011, 05:01 PM
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How did you come to the conclusion that you were going to have 12.75 cr ??
 
  #53  
Old 05-14-2011, 12:32 AM
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Yeah, 12.75 is a lot of compression, that's a little more than what my dad's 427 makes.

How are you making that?
 
  #54  
Old 05-14-2011, 12:57 AM
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I used this:
Sick's Engine Compression Ratio Calculator

I could be horribly wrong in plugging numbers in, but here's what I did.

1
4
3.48
4.166
0.039
60
0
-0.027

I got the head gasket specs off the packaging and had to google the specs of the L98 pistons, so it might be inaccurate there, but I came out with 12.34 compression ratio. I must've done something different last time 'cause I remember coming out higher than that, but anyway.

If I'm wrong and my compression ratio is actually lower than that, well good; that makes it easier I guess.
 
  #55  
Old 05-14-2011, 08:41 AM
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Your 10-bolt rear end will be fine. I a running 500hp, a 3000 stall and slicks on my stock 10-bolts. A friend runs 10 seconds on his stock 10 bolts. We both have miny spools.
 
  #56  
Old 05-16-2011, 08:51 AM
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can you at least put next to each number the measurement? some of those arent making sense to me. but yea, something is a wee bit off
 
  #57  
Old 05-16-2011, 12:13 PM
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Hopefully it's way off or you're going to be buying lots of race gas
 
  #58  
Old 05-17-2011, 12:53 AM
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Originally Posted by microkid
can you at least put next to each number the measurement? some of those arent making sense to me. but yea, something is a wee bit off
Sorry man, here:

Enter Bore/Stroke Designation Type - 1 (Inches)
Enter Cylinder Bore Size - 4
Enter Piston Stroke Length - 3.48
Enter Head Gasket Bore Diameter 4.166
Enter Compressed Head Gasket Thickness - 0.039
Enter Combustion Chamber Volume In CCs - 60
Enter Piston Dome Volume In CCs Negative For Dished Pistons (Use '-') - 0
Enter Piston Deck Clearance Negative If ABOVE Deck (Use '-') - -0.027
 
  #59  
Old 05-17-2011, 07:57 AM
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where did you get the specs for the heads? 60cc is awful small. stock iron heads are 76cc i believe and most aftermarket heads are around 67cc for street use, but of course availible smaller.
 
  #60  
Old 05-17-2011, 09:05 AM
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Originally Posted by Saint Ebony
I used this:
Sick's Engine Compression Ratio Calculator
I could be horribly wrong in plugging numbers in, but here's what I did.
1
4
3.48
4.166
0.039
60
0
-0.027
"0" - means the engine has flat top pistons, does it?
"-0.027" - The deck height is the amount that the block is above the pistons. You used a negative number, which means the pistons are popping out above the block by that amount. That would mean the block has been decked quite a lot! Is that what you meant as well?
 


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