Besides all the differences internally, a 6 bolt would make for a faster clutch / flywheel swap as you'd have one less bolt to take off, and put back on

I'll probably putting my 2.0 6 bolt block / crank / rods / pistons up for sale in a month or two. The crank needs refinishing as a rod bearing spun. Any motor will do well as long as you don't skimp out on parts, and have it properly built (blue printed).

 

cause the 7 bolts do it just a little more than 6 bolts do.

6 bolt doesn't do it at all, unless you bearings die.

 

1g head has bigger intake and exhaust ports bigger means more power!!

 

Besides all the differences internally, a 6 bolt would make for a faster clutch / flywheel swap as you'd have one less bolt to take off, and put back on

I'll probably putting my 2.0 6 bolt block / crank / rods / pistons up for sale in a month or two. The crank needs refinishing as a rod bearing spun. Any motor will do well as long as you don't skimp out on parts, and have it properly built (blue printed).

The clutch swap would not be faster, because you dont have to remove the flywheel

Also you should not re finish the 4g63 crank. The journals are specially hardened from the factory, regrinding them is a no-no.

I have a 2g sitting in my yard with a fully built 6-bolt from Jackson Auto Machine that is crankwalked. So much for that idea.

 

The clutch swap would not be faster, because you dont have to remove the flywheel

Also you should not re finish the 4g63 crank. The journals are specially hardened from the factory, regrinding them is a no-no.

I have a 2g sitting in my yard with a fully built 6-bolt from Jackson Auto Machine that is crankwalked. So much for that idea.

I heard the same thing for 6 bolts as well so i dont know where you got your info from hustler. anyway as far as holding up a decent street, strip set-up using a 7-bolt....would that be ok and is there anyone on here who can gimmie some input if you have done a 7-bolt build

 

I heard the same thing for 6 bolts as well so i dont know where you got your info from hustler. anyway as far as holding up a decent street, strip set-up using a 7-bolt....would that be ok and is there anyone on here who can gimmie some input if you have done a 7-bolt build

I had my 7-bolt done with a cometic HP headgasket,Evo3 16G,Intake,MBC set at 18psi,Greddy Type-s BOV, upper IC piping,2G install kit,Walboro255 LPH,650cc injectors,and a 3" exhaust from the turbo back. With this setup i put down 246 all wheel HP. This is like 310 to a FWD. I was also only running the side mount instead of a FMIC. Now, i blew this motor up partially to crankwalk and bad tuning. I had no problem destroying camaro's and mustang's for fun on the weekends. I am now putting a J-spec 7-bolt in. It wont be as fast for right now but it will run again and thats all that matters. Also if you want to re-do the bottom end on ur 7-bolt, you def need an aftermarket crank, they walk in ever 2g sooner or later. Every guy i know with a 2g has had it happen.

 

1g head has bigger intake and exhaust ports bigger means more power!!

can't you just port the 7-bolt since thats what he has anyways?

 

It seems like they're pretty similar motors as far as performance, but aside from the 'c' word, the tradeoff seems to be the weight and strength of the internals.

7 bolt rods and crank are lighter, meaning slightly less rotating mass. The advantage is a few more useable Hp (not a lot).

The disadvantage is less surface area for the bearings (but not much less than the 6 bolt), and less strength in the rods (usually 50-100hp depending on who you ask).

The 2g head is a better design but completely stock can't flow as much as a 1g head. The 2g head can be ported for a 1g manifold and used on a 1g block:
http://home.comcast.net/~saramasters

 

thanks for the info drcustom, I was just discussing in another post how much boost you can run safely on stock 7-bolt pistons/connecting rods... you wouldn't happen to know would you?

 

thanks for the info drcustom, I was just discussing in another post how much boost you can run safely on stock 7-bolt pistons/connecting rods... you wouldn't happen to know would you?

I have been reading up ont his b/c I plan to do turbo my 93 Talon ES and it has a 7-bolt motor I have read where ppl have ran 10PSI and not done any harm but then i have read where ppl has ran 10PSI and destroyed a bunch of stuff I dont plan to run anymore than 7 with my car but a 2g may be stronger who knows

 

there is a crankwalk fix out there the guy does it for 200-300 i think its worth it and its cheaper then a 6bolt block

 

there is a crankwalk fix out there the guy does it for 200-300 i think its worth it and its cheaper then a 6bolt block

There is no proven fix, so please don't spread mis-information.

 

1g head has bigger intake and exhaust ports bigger means more power!!

2g (97+) heads have better cooling passages and can be ported out overall larger than 1g heads

2g 95 and 96 heads share the same casting as the 7bolt 1g heads their ports just aren't as big.

 

how much boost you can run safely on stock 7-bolt pistons/connecting rods

It's more important that you can control knock, so it really depends on the turbo, fuel, intercooler, and stuff like that. Most people say between 17-19 psi and 350-400hp is about the max safe on a stock 7 bolt block, but more than that you start to hear about problems. If you want long term reliability and don't want to take any chances then keep it around 17psi.

There is no proven fix, so please don't spread mis-information.

That's actually a guy out here in Colorado Springs. It's $200 if the motor is out of the car, $400 if it's still in. He gurantees that the motor won't walk, and he stands behind his work. I don't have a 7 bolt, but I'd definitely take it to him if I did.

 

The disadvantage is less surface area for the bearings (but not much less than the 6 bolt), and less strength in the rods (usually 50-100hp depending on who you ask).

If you know anything about old school V8s, you'll know that bigger bearings aren't always better. As an example, many Ford engine builders use the FE block instead of the Windsor block, citing smaller main bearing as one of the advantages.

Most people say between 17-19 psi and 350-400hp is about the max safe on a stock 7 bolt block, but more than that you start to hear about problems. If you want long term reliability and don't want to take any chances then keep it around 17psi.

Tort's running 30psi with a 20g on a bone stock 1G 7 bolt bottom end with 134k, and it's still running fine. I ran 25psi on my Green for years on my 7 bolt. Jim McKeone of JM fab. runs my old Green on his 7 bolt at 25psi fine. Also consider EVOs. Their rods are similar in size to 7 bolt rods, and they've made well over 500whp.

It's more important that you can control knock

That is the real key to a solid, reliable engine - whether it's a 6 bolt or a 7 bolt.

 

Crankwalk aside if you are doing a mild build of a 7 bolt there is really no disadvantage to it in the real world. Like Steve said above even unopened 7 bolts can go very far if you can tune and run the right parts to support the power. For some reason people's jaws drop when I tell them I haven't swapped in a 6 bolt yet. The way I look at it I don't need to spend the money on a motor if mine is holding up just fine.
26psi on pump gas and propane injection everyday I drive it. Traps over 120 on my street tune and has never hiccuped in 6 years.

 

it all comes down to compression ratio at that point that limits the 7bolt compared to the 6bolt..you really can't say one's internals are stronger than anothers from 92+ as there are very little differences, but the whole 7.8:1 and 8.5:1 makes a big difference in limiting power from knock with "said set of mods"

 

it all comes down to compression ratio at that point that limits the 7bolt compared to the 6bolt..you really can't say one's internals are stronger than anothers from 92+ as there are very little differences, but the whole 7.8:1 and 8.5:1 makes a big difference in limiting power from knock with "said set of mods"

That's a 1G vs 2G arguement, NOT a 6 bolt vs 7 bolt one - 1G 7 bolts are 7.8:1 just like 6 bolts. Besides, there are many mild 6 bolt builds using 2G 8.5:1 pistons that run just fine.

 

That's a 1G vs 2G arguement, NOT a 6 bolt vs 7 bolt one - 1G 7 bolts are 7.8:1 just like 6 bolts. Besides, there are many mild 6 bolt builds using 2G 8.5:1 pistons that run just fine.

well he has a 97 and he was talking about swapping in a 6 bolt but decided against it to just build his 7 bolt....so where in that are we talking about a 1g 7 bolt?

 

Ive been running my turboed nonturbo 1g 7 bolt 9 to 1 ratio at 190 compression at 18 psi for a couple years now without problems, knock on wood. I think if you keep it properly tuned and away from knock you can do alot. Fuel control with a SAFC or comparable gives amazing results. You should be fine if you take care of it and tune it properly. Tuning really puts it all together and gives you the best power.

 

we're talking about big hp numbers and what limits power potential, not 18psi on 190 compression with a stokc sized turbo

 

2g (97+) heads have better cooling passages and can be ported out overall larger than 1g heads

2g 95 and 96 heads share the same casting as the 7bolt 1g heads their ports just aren't as big.

Are you sure about the cooling passages? So 97-98 heads cool better (As far as water flow is concerned) than all other head designs?

 

I have also heard, dont quote me on this, but the 97+ heads ported will outflow a ported 1g head.

 

Sorry man someone asked about the reliability of high compression and running around 18 psi on a 7 bolt. Take it easy.

 

There are no pros and cons 6 bolt hands down.