4” stroke clearance? Lt1/lt4 Block difference

Goohead · 10-10-2019, 08:59 PM

Had 2 questions:

What if any clearance modification needs to be done to the block for a 4” stroke crank

Anyone know what the difference in the lt1/lt4 BARE block?

Lt1 part #: 12619171
Lt4 part#: 19329617

Thinking about a winter project if I keep the car and wanted to see if anyone can help me answer these 2 last points.

Lastly, aside from on the loose side of spec, does anyone have any bearing clearance, ring gap recommendations for ~15-18lbs of boost? Thanks

KingLT1 · 10-10-2019, 09:42 PM

This doesn't answer your question, but More stroke is the last thing you need for boost engine.

Goohead · 10-12-2019, 12:01 AM

Thanks, just looking for the facts to the question above

Goohead · 10-13-2019, 07:54 PM

So one thing I found out; it seems piston oil squirter will need to be removed or the block machine for some 4” stroke clearance ones Katech sells. Alternative might be able to just plug the squirters and not run them. Less piston cooling, more bearing oil pressure...

Puddin · 10-13-2019, 09:59 PM

Talk to Texas Speed as they still use the Piston squirters too.They just did my 427 shortblock and answered all the questions I asked so I don't see why they couldn't answer yours.

Goohead · 10-19-2019, 11:16 AM

Don’t know if they will freely give someone info that’s didn’t plan on using them to build the block?

Wanted to do some research before jumping in, do the build in a “home” garage and post up a walk through after wards.

Didn’t know if there things I would run into:
Rod BE clearance to bottom of sleeve
Piston skirt to squirter clearance (issue found)
Reluctor wheel clearance
Cam clearance
Main fillet bearing clearance on aftermarket crank

Ultimately I was going to document the journey for anyone else that wanted to tackle this in the future and was going to leverage this community to share some knowledge.

10-10-2019, 08:59 PM	#1
Goohead Horsepower whisperer Drives: Camaro Join Date: Jun 2017 Location: MO Posts: 185	4” stroke clearance? Lt1/lt4 Block difference Had 2 questions: What if any clearance modification needs to be done to the block for a 4” stroke crank Anyone know what the difference in the lt1/lt4 BARE block? Lt1 part #: 12619171 Lt4 part#: 19329617 Thinking about a winter project if I keep the car and wanted to see if anyone can help me answer these 2 last points. Lastly, aside from on the loose side of spec, does anyone have any bearing clearance, ring gap recommendations for ~15-18lbs of boost? Thanks

10-10-2019, 09:42 PM	#2
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,793	This doesn't answer your question, but More stroke is the last thing you need for boost engine. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

10-12-2019, 12:01 AM	#3
Goohead Horsepower whisperer Drives: Camaro Join Date: Jun 2017 Location: MO Posts: 185	Thanks, just looking for the facts to the question above

10-13-2019, 07:54 PM	#4
Goohead Horsepower whisperer Drives: Camaro Join Date: Jun 2017 Location: MO Posts: 185	So one thing I found out; it seems piston oil squirter will need to be removed or the block machine for some 4” stroke clearance ones Katech sells. Alternative might be able to just plug the squirters and not run them. Less piston cooling, more bearing oil pressure...

10-13-2019, 09:59 PM	#5
Puddin Drives: 2016 Camaro 2SS Join Date: Apr 2018 Location: Central Texas Posts: 1,011	Talk to Texas Speed as they still use the Piston squirters too.They just did my 427 shortblock and answered all the questions I asked so I don't see why they couldn't answer yours.

10-19-2019, 11:16 AM	#6
Goohead Horsepower whisperer Drives: Camaro Join Date: Jun 2017 Location: MO Posts: 185	Don’t know if they will freely give someone info that’s didn’t plan on using them to build the block? Wanted to do some research before jumping in, do the build in a “home” garage and post up a walk through after wards. Didn’t know if there things I would run into: Rod BE clearance to bottom of sleeve Piston skirt to squirter clearance (issue found) Reluctor wheel clearance Cam clearance Main fillet bearing clearance on aftermarket crank Ultimately I was going to document the journey for anyone else that wanted to tackle this in the future and was going to leverage this community to share some knowledge.

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