4g61t.org

So, I just checked out a Colt - I did a compression test on it and got 180 across the board on a 4g63 motor (I checked the block and it said 4g63). Now I know that if it has 2g pistons in it, it'll raise the compression to 185 (assuming that the pistons are brand new). But my question is: if you were to put the 4g61 head on the 4g63 block would it fit and if so, would it raise the compression to that of 180 in all 4 cylinders?

Thank you in advance, I truly appreciate all the help I've had from this forum.

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Isabelle Knobel
1990 Eagle Talon TSi AWD
2005 Acura RSX-S
2003 Suzuki GSX-R600

Why would you put a 4g61 head on that block? I'm sure the head would bolt on to the block, but I think the bore sizes are different, and I'm sure the 4g61 has a different-sized combustion chamber, but I don't know if it's smaller or larger. I am guessing smaller, which would raise compression.

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91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

http://www.facebook.com/captaintonus

Trust me, I wouldn't put the 4g61 head on the 4g63 block if I had it my way. I went to go look at a Colt earlier and it had extremely high compression. My 1g has stock pistons and it made 150 across the board. I know brand new 2g pistons in a 4g63 will raise the compression to 180 but I figured having a 4g61 head on a 4g63 block would also raise the compression. I would imagine that it would but I wasn't sure so I figured I would ask.

The guy that owns the car right now said that the previous owner crashed his Talon and put the motor into the Colt. He also said that he built the block. Naturally, I asked what he used for the block and the guy had no idea. It would make sense for him to have put 2g pistons in it but there isn't any way to be sure unless I were to take the head off. But since this guy had no idea what was put into it, my guess is either 2g pistons or a 4g61 head.

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Isabelle Knobel
1990 Eagle Talon TSi AWD
2005 Acura RSX-S
2003 Suzuki GSX-R600

4G61 head has 43cc and 4G63 head 47cc combustion chamber

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http://www.facebook.com/c58.org

It could also be a 4G67 head, which is literally exactly the same as a 4g63 head, except it has smaller combustion chambers, which bump up compression. The 4g61 head is unlikely, because it has smaller intake ports, which would require a different intake manifold.

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91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

http://www.facebook.com/captaintonus

Thats right, the best is a 4G67 Head. It also has the ''G'' camshafts in it.

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http://www.facebook.com/c58.org

I'm pretty sure the Colt I looked at had a 4g63 longblock in it. When I looked into the engine, I saw the letter D stamped into each piston. That's what 2g pistons have stamped on them. Those would also read compression at 180/ 185 depending on how new they were. Before I did the research for those, I figured the 4g61 head would raise the compression but I wasn't sure so I'd ask.

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Isabelle Knobel
1990 Eagle Talon TSi AWD
2005 Acura RSX-S
2003 Suzuki GSX-R600

The 'D" just indicates that they came from a DOHC motor. My 4g61t pisons had "61DT" on them and the 1G 4g63 ones have "63DT" on them. If they just had a D then they are N/T pistons and are indeed higher compression (duh)

~joe