Marine Intake

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L31MaxExpress

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Where can I find the l31 marine intake?
Since I am taking a break on the back here, will answer. I have had 2 of these. One came from a man in Oklahoma back in 2013ish. He was a member of the old Pacific Audio board. Second one came from a guy down in San Antonio that went with a LS3 instead. I also have a couple other Marine intakes that I have bought. One from a guy Carl, InTech on gearhead-efi.com and another off Ebay. I do not know if Carl has any currently but he sold several of them a few years ago.
 
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Supercharged111

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Emissions, they started doing a visual which the marine failed. Its 25 years old now, so exempt in the state of Texas.

The transient fueling has never been great on mine, even when it was stock. I just added to the Impact factor until the thing stopped popping back from the intake which it was doing even with the 350 and stock L31 manifold after I put a converter into it.

I didn't have great luck just globally bumping that table. I've had better luck increasing the delta between the load cells, but haven't been able to be very scientific about said bumps.
 

L31MaxExpress

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Rear of the engine is starting to come apart now. Truck manifold and valve covers should be off in about 1 hour after I take a break for lunch.

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L31MaxExpress

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Well my goal of getting it fired up today is not going to happen. Discovered I still have a head bolt seeping coolant. Going to bite the bullet, pull each one, one at a time and reseal all the ones that are internal to the engine. If any of the lower ones leak I will deal with it later. This is the first small block I have ever built that has leaked coolant from the head bolts. Same method and same sealer as my previous engine builds. Either Permetex has gone to down the drain or these Jegs head bolts are special.
 

Supercharged111

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Well my goal of getting it fired up today is not going to happen. Discovered I still have a head bolt seeping coolant. Going to bite the bullet, pull each one, one at a time and reseal all the ones that are internal to the engine. If any of the lower ones leak I will deal with it later. This is the first small block I have ever built that has leaked coolant from the head bolts. Same method and same sealer as my previous engine builds. Either Permetex has gone to down the drain or these Jegs head bolts are special.

What was your evidence of a leaking head bolt? I sometimes wonder if that's what my LT1 does too.
 

L31MaxExpress

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What was your evidence of a leaking head bolt? I sometimes wonder if that's what my LT1 does too.
It has enough of a leak you can see the trail of coolant seeping down from between the valve springs. Coolant is puddeled up around the shorter bolt next to the drain back hole. I put 100 miles on it last time I drove it a week ago. Has not run since. Looks like it leaked after it was parked. The oil puddled up around the perimeter bolt boss is clean. Its peaking out of the bolt between the rockers.

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L31MaxExpress

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Hopefully fixed an issue that has plagued me since this inexpensive score went on even my old 350. GM PCM can command 310 steps on the IAC. The BBK throttle body was drilled for a 5/16" hole. I was able to get a 3/8" drill bit down through the IAC passage ways without breaking through the casting and then slightly wallow it wider side to side as well as debur an area under the IAC pintle seat without damaging the seat. I now have more than a 3/8" IAC passageway. This will give me about 40% more IAC air. IAC was previously at maximum flow around 160 counts. 40% more flow should make it able to increase flow until around 220 counts. With any luck it will fix my low idle on cold starts without having to have the engine idle higher than I want it to hot in Park by having the air rate screw cranked open. This plagues almost all GM based BBK throttle bodies from TPI on.

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0xDEADBEEF

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I knew that other intake was all wrong for you. Good luck with the swap.
 
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