Camaro 3.1, 3.4, and 3400 parts needed

[bachert24]

Yup 3.4 block, that was my concern. I want to keep the compression down.

[caffeine]

3100 heads will net you the same compression but less flow, so not worth it haha.

Since you have a 3.4 block you can actually run 3500 heads and those WILL lower the compression a bit compared to 3400 heads. They also flow better in stock form.

[bachert24]

And those are bolt on too? I'm assuming I'll need that intake as well?

[caffeine]

Ya 3500 heads bolt on with the matching lower intake. You can run a 3400 OR 3500 upper intake with that. If this is going in a 4th gen I don't think the 3500 upper fits under the cowl but the 3400 upper does.

I don't have any 3500 heads to sell but I do have a 3500 lower and upper intake.

[bachert24]

How much? It is going on a 4th gen so I'll need the 3400 upper.

[Guest]

I'm going to suggest that for now you don't buy anything.

Do a lot more research, and find out exactly what works, what you need and why you need that particular combination of parts.

What do you want to keep the SCR below? IIRC the 3500 heads on a 3.4 with a 3.4 headgasket was around 11:1 or so. There's a compression calculator somewhere on this site that will help determine more closely, based on actual parts that you use.

[bachert24]

Ok so I went ahead and did some research. If my calculations are correct I am coming up with a compression that is way too high! Here is what I have included in the build. Assume all parts are stock.

Bore - 3.622" (3.4L)
Stroke - 3.307" (3.4L)
Head Gasket Bore - 3.8" (used the 3500 to lower compression a tad)
Head gasket compressed thickness - .060 (again I used the 3500 to lower the compression)
Combustion chamber volume - 32.4 cc (3500, this Is well below that of the iron heads 48.5 cc and I assume the major factor in the compression difference)
Piston Dome Volume - +8 cc (3.4L)
Piston Deck Clearance - .0095" (3.4L)

[Guest]

What did you come up with for an SCR?

Also I'm not sure how the calculator that you used works exactly, but the 3.4 piston has a dish, not a dome, and depending on how the math works, you may need to make it a negative number.

[bachert24]

If they are in fact dished at 8cc then I am looking at a 16 SCR. Way too high! I may have to find some domed 20cc pistons if they exist.

[bachert24]

Nevermind I am an idiot, it was right the first time, you enter a +for a domed piston, so If I get a 20cc dished piston I can get the compression down to 9.7. The 3500 piston is 3.7 x 3.310 with 24.5cc volume, perfect volume, but too big, the 3400 pistons however are 3.622 x 3.310 and have 28.6 cc pistons. Will the 3.307 vs 3.310 stroke matter? I would imagine not.

[caffeine]

The 3400 piston with 3500 heads IIRC would be about 9.2:1. With 3400 heads and 3400 pistons you should end up at stock 3400 compression which is 9.5:1

[bachert24]

The 3400 piston with 3500 heads IIRC would be about 9.2:1. With 3400 heads and 3400 pistons you should end up at stock 3400 compression which is 9.5:1

Looks like my plan will be as follows
From 3.4L : Bottom end minus pistons/rods, head gaskets
3400 : Upper Intake, throttle body, pistons/rods
3500 : Heads, lower intake

This will net me almost exactly 9:1 Static Compression Ratio, which is right where I want to be. This will allow me to add a custom Supercharger next summer.

I am going to start a new thread now that I know more info. thanks for all the help guys!

[caffeine]

You will need 3400 head gaskets to work with the 3400 pistons.

[bachert24]

You will need 3400 head gaskets to work with the 3400 pistons.

both the 3.4L and 3400 have the same 3.75" bore in the head gasket and .040" compressed thickness to I think they are identical. The difference between the pistons is only the size of the dish and a .003 difference in stroke. Correct me if I am wrong, but I can use either head gasket? Unless the 3500 cylinder head requires the 3400 head gasket? That would make sense actually lol.

[Guest]

The 3.4 gasket is 0.040", yes, the 3400 gasket however is 0.060". This is because the 3400 piston comes proud of the block by 0.020". Using too thin of a gasket can lead to the piston and head meeting each other.

Also strokes are exactly the same between the 3.4 and 3400.