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1g and 2g 4g63

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Tammalynn

Probationary Member
11
0
Feb 8, 2011
Scottdale, Pennsylvania
I've heard that the 4g63 engine from the 1st gen was built stronger than a 4g63 from a 2nd gen. I don't know much about them and haven't been able to truly compare them. And if the 1st gen 4g63 is built better, how different is it from a 2nd gen? Is it easily swapped or will it need conversions? :confused:
 
The only reason people say the 6 bolt (1st gen) is stronger is because everyone blew the crankwalk with 7 bolt blocks (2G from 95-97) issue way out of perportion. Chances are you will never have to worry about CW with any DSM you buy. Also 98-99 blocks are not said to be prone to CW becayse they have a split trust bearing. Yes it takes modification to put a 6 bolt into a 2G car.
 
The only reason people say the 6 bolt (1st gen) is stronger is because everyone blew the crankwalk with 7 bolt blocks (2G from 95-97) issue way out of perportion. Chances are you will never have to worry about CW with any DSM you buy. Also 98-99 blocks are not said to be prone to CW becayse they have a split trust bearing. Yes it takes modification to put a 6 bolt into a 2G car.
6 bolt uses a stronger rod, so yes it is a stronger motor.


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The engines are pretty much identical in most ways that i have came across. The 14b turbo that comes with manual 1g's are larger than the 2g t-25. And the 1g comes with a 6 bolt flywheel rather than a 7-bolt like with the 2g. There might be a few minor differences here and there but nothing drastic. the 2gen intake manifold flows a little better. i have swapped a 7bolt with a six bolt and 6 bolt with 7 bolt. 7 bolts are from what i hear more likely to crankwalk. again i have not ran into any issues. one thing i have came across in my dsm play time that was kinda annoying was the 90 came with an oil cooler. and there are a few couplers that are moved around noting that will completely ruin your day tho.
 
This is what I have come across on this board.
1g = 6 bolt
2g = 7 bolt

6 bolts have stronger rods = able to withstand more horsepower.
2g heads flow better.
2g pistons are better.
2g exhaust manifold flows better.
1g has a slightly bigger intercooler, which is good if you have the 14b from a manual 1g. Will not bolt on to a 2g without modification.
1g blow off valve is better since the 2g bov leaks.

best combo = 6bolt block with 1g rods and 2g pistons with a 2g head.

correct me if I am wrong please.
 
This is what I have come across on this board.
1g = 6 bolt
2g = 7 bolt

6 bolts have stronger rods = able to withstand more horsepower.
2g heads flow better.
2g pistons are better.
2g exhaust manifold flows better.
1g has a slightly bigger intercooler, which is good if you have the 14b from a manual 1g. Will not bolt on to a 2g without modification.
1g blow off valve is better since the 2g bov leaks.

best combo = 6bolt block with 1g rods and 2g pistons with a 2g head.

correct me if I am wrong please.

1Ga = 6 bolt
1Gb and 2G = 7 bolt
2G heads flow different, not better.
2G pistons have a higher compression ratio, not better.
The best combo depends greatly on what you want to do with the car.
The rest is accurate enough.
 
The 2g head is a much better design and velocity wins over mass air flow until you are reaching the flow point where it becomes a restriction. Many top vehicles are running 2g heads for the velocity.

If I really had a choice, I'd build up a 98/99 7 bolt as it has less rotational mass by having a smaller crank. Plus it'll drop right in on my vehicle and I wouldn't have to turn off a CEL check for random misfires.
 
1g block, 2g head, 1g pistons (for lower compression ratios which will allow more boost, correct me if I'm wrong), should sit in fine...

It's not quite as simple as lower CR = more boost and thus more power, but given a certain fuel, yes, you can run higher boost with lower compression ratios, though that's not always a good way to get your power.
 
I agree, but I was trying to simplify...
If I turbo the stock engine I have (throwing out strength) with a higher compression then my engine would blow quicker under less boost than something with a lower compression ratio...
but a higher compression ratio helps too, more so on N/T cars though...
but I would still stay low for turbo...
that way I could run more boost without worry...
 
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