Lucky #13...Back in the saddle....92 rt/tt

[niterydr]

Can you guys use the 6g75 3.8L's or no. That would make some mad TQ!

There are some guys using the 6g74 with 6g75 crank and 6g75 mivec heads.

The worry is that the 6g75 service limit for overbore is less than the 6g74 so the block maybe to thin for a serious overbore. A 6g75 crank drops into the 74 block and with an offset piston pin gets it around a 3.8L engine with the block thickness of the 74.

The 6g75 MIVEC SOHC heads seriously outflow the 6g72/6g74 heads (virtually the same in most models), but getting it to fit under the hood on a 6g74 block is a pita.

However, the 6g75 heads on a 6g72 block with an offset ground 6g74 crank should fit easier (12mm shorter). I don't think anyone has done that, but I know if plenty of people that do the 6g74 crank in the 72 block with an offset grind and custom pistons/rods, gets it to a 3.4-3.7L with decent piston speeds.


Just comes down to how much you want to spend. I am leaning towards just a good old 3.1 (smallish overbore on a 4-bolt factory block), unless I come into a money tree ,then I'll do the offset ground 6g74 crank for a "sleeper" 3.5L.

[goodhart]

I have a 6g75 that had the timing belt break on it if you are interested in parts.

[turbotalon1g]

whatever is cheap and will hold 100more whp/tq you want to make gets my vote, also strokers for street cars!

[niterydr]

I just realized I didn't post the "progress" charts...

The 9b's are probably cores now which sucks because we spiked over 26.5psi out of them! :bengals:(hit fuel cut at 26 psi @3500 or so). Still only 14psi or so at redline, but had a good area under the curve.
22psi to 14psi = 348hp/422tq
25.8psi to 14psi = 368hp/480tq
24.5psi to 14psi = 345hp/455tq

http://forums.mn3s.org/download/file.php?id=712
Green pull was "close enough" at 21psi spike-14 to redline. Wanted to leave some on the table. Then we decided to turn it up to an all boost setting (ramp it up fast), which is the blue graph. Timing is VERY conservative on that pull under higher boost, as we had not ventured that high yet in the map.

Car started to misfire at 6100rpm, so we shut down. The power dip wasn't to concerning as we had pulled some timing for safety and figured it would be down on power, the misfire was a bit concerning, hence the shutdown. Checked the car over and it seemed okay, so we figured the misfire was from the lack of timing we added back the timing that worked, see the red graph.

When the car nosed off again up top, something was not right obviously.

We didn't hear much noise (sounded like Throw-out bearing chatter) so did another quick pull starting at 3000, 4300rpm hits, BOOM, smoke screen, car noses over, clutch in, coast to the side of the road. car is still running but sounds like a bag of marbles in a washing machine, shut it down and coast to the side of the road.


My analysis:
Odds are the damage was done @5100rpm on the red pull when it nosed over. Technically it could have actually happened around 5900rpm on the pull before, but I just can't believe that the car made one last go at it and made similar if not more power on the red pull (until it nosed off).

Spun the bearing there and dropped out the cylinder (red graph), next pull was just icing on the death cake. Should have just called it when we heard the chatter instead of assuming it was the loose TOB (weak slave cylinder), 155,800 miles on it with an unknown history=shit happens.

I will have to tear this one down to see what happened. E-85 doesn't show knock on the AEM really. However this motor was quieter from a knock noise standpoint compared to most 3/s I see (pump or E-85, under 1V). When the motor let go, it hit 4V. End of the red pull it was 2V or so....I really really don't think it was detonating, but the motor will tell the story.

[niterydr]

Drained the oil today, first thing out was about a 1/2-1 gallon of coolant...that isn't good.

Poked around in the oil pan holes, found a chunk of rod, looked at the rear hole (Now that it is lifted up), GIANT hole in the block.

I don't really give a rip about the 2 bolt shortblock, just hope the heads are fine as those can get spendy.

Ordered a forged crank that should only need a micropolish and have a line on a 4 bolt block.

Also have a line on forged rods, waiting on a piston quote, and found a TD05 14B kit (7cm housings).

[niterydr]

Forged rods ordered with ARP2000 fasteners.

Old school Titan 14b kit ordered. Features twin 14b's with Forced Performance 7cm housings (ported), Titan bending "old school" manifolds and 02 housings, and a 4" outlet downpipe. (bit overkill but eh, I'll run 4" to twin 3" catback mufflers).

6g72 shortblock core
6g72 balance/polish crank
6g72 oil pan
6g72 cp pistons
OEM rebuild gasket kit
oem oil pump
OEM head bolts
Oem main bolts
Oil cooler setup
ACL Bearings
machine work

is the rest of the setup, needs to be ordered/sourced. Also looking at a 4-bolt block on Sunday.

[turbotalon1g]

damn dude, looks like you might have this beast back in time for PG!

You could rock SA/U with that setup!

[niterydr]

damn dude, looks like you might have this beast back in time for PG!

You could rock SA/U with that setup!

No way in hell, hoping to get to the track before end of season. There is always the 5th annual MAP proving grounds.

I am swamped with customer work and then going on Vacation from June 8th thru June 17th, so its not happening. However John's Galant is looking like it is on progress :beer:

[turbotalon1g]

Nice, yeah I know that feeling if i make it this year it will be my first racing there.

[niterydr]

Oil pan in-route, looking at a block on Sunday if it checks out, ordering pistons.