408 opinions
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408 opinions Anybody build a 4" stroke iron block motor but wished the stayed stock stroke? I'm looking to build a 408 for drag car but the reports of piston wear has me second guessing.
I need about 575 to the tire n/a to run 10 flat.
I need about 575 to the tire n/a to run 10 flat.
Some of the best in the business will tell you not to put a 4" crank in anything other than an LS7, LSX, or aftermarket block but it's been done many times over. From what your describing this is a dedicated racing engine so I assume you go back into your motors often. This would be a deciding factor for me and personally I would be thinking max stroke and bore to get as much power as I could if staying n/a.
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From: Coast of San Mateo County Between Pacifica & HMB
How heavy is the car?
Stick or auto?
Intake or hood limitations?
Trailer or Street driven %?
Lots of blanks to fill in to get some accurate recomendations.
There are plenty of good SHORT pistons to accomodate a 4.00" Stroke if
that is what you need or want.
Stick or auto?
Intake or hood limitations?
Trailer or Street driven %?
Lots of blanks to fill in to get some accurate recomendations.
There are plenty of good SHORT pistons to accomodate a 4.00" Stroke if
that is what you need or want.
Last edited by NAVYBLUE210; Sep 8, 2019 at 01:04 PM.
Plenty of pistons out there the keep the bulk of the skirt in the bore at BDC, don’t be worried. Last one I saw the skirt was coming out of the bore by maybe an 1/8 of an inch. Nothing to worry about IMO.
Bore > stroke. Look at all the 408 builds that get stuck in the 480-530 range. You would do better to get a used ls7 short block. Or if you are wanting to build something and keep 3.622 crank, build a 388
I went from a stock stroke to a 4.250” stroke crank in my iron block, no problems here. I just changed my oil and cut open the filter and no sign of the piston skirts wearing prematurely.
The skirt wear problems you’ve heard about are mostly a thing of the past. Its a result of poor piston selection and/or poor machining/assembly. Purchase your short lock from a reputable vendor and you shouldn’t have to worry about it.
The skirt wear problems you’ve heard about are mostly a thing of the past. Its a result of poor piston selection and/or poor machining/assembly. Purchase your short lock from a reputable vendor and you shouldn’t have to worry about it.
I have a 408 with a roots blower, I'm not worried about skirt wear because I don't expect the engine to last 100,000 miles but I do expect it to last quite a while and piston wear probably won't be the determining factor.
With good heads you can easily meet your goal.
With good heads you can easily meet your goal.
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TECH Apprentice
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Seems like all positive input on a 408. Thanks for your input.
For you detailed guys. This is going into a drag only car. Will get raced alot bracket car mostly with a handful of nitrous passes. I am very comfortable with shooting 300 on top.
Got 2 full seasons out of my trusty 370 time to upgrade.
For you detailed guys. This is going into a drag only car. Will get raced alot bracket car mostly with a handful of nitrous passes. I am very comfortable with shooting 300 on top.
Got 2 full seasons out of my trusty 370 time to upgrade.
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Verdad Gallardo TECH Fanatic
Joined: Aug 2009
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From: Coast of San Mateo County Between Pacifica & HMB
Seems like all positive input on a 408. Thanks for your input.
For you detailed guys. This is going into a drag only car. Will get raced alot bracket car mostly with a handful of nitrous passes. I am very comfortable with shooting 300 on top.
Got 2 full seasons out of my trusty 370 time to upgrade.
For you detailed guys. This is going into a drag only car. Will get raced alot bracket car mostly with a handful of nitrous passes. I am very comfortable with shooting 300 on top.
Got 2 full seasons out of my trusty 370 time to upgrade.
AFR or TFS LS3 heads with light valves, LLSR, and a CHI Intake would be my formula.
Really like Darths 388" plan as well.
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Skirt wear should be minimal with modern piston designs from reputable companies. 575 wheel should be easy if you set it up right. Won't drive "like stock" but I'm assuming you know that. Only thing I regret is not having the funds to build an ls7. The heads are much better.
Seems like all positive input on a 408. Thanks for your input.
For you detailed guys. This is going into a drag only car. Will get raced alot bracket car mostly with a handful of nitrous passes. I am very comfortable with shooting 300 on top.
Got 2 full seasons out of my trusty 370 time to upgrade.
For you detailed guys. This is going into a drag only car. Will get raced alot bracket car mostly with a handful of nitrous passes. I am very comfortable with shooting 300 on top.
Got 2 full seasons out of my trusty 370 time to upgrade.
408 stroker 200 shot dyno pull 782hp 608 on the torque.
408 would be an ideal drag motor with the 4” stroke, the extra arm will help pick your car up and move it from a standing start position, which is big part of what you’re doing. Don’t be timid about putting compression in it either, a cam with 25* or more degrees of overlap and a real good set of heads are the ticket. Just stay away from LS6 intakes, 243 heads and all the other inexpensive internet wonders that have serious limitations that so many put on their 408s, 575rwhp will take a max effort build with 1.4 hp at the tire per cubic inch.
Thread Starter
TECH Apprentice
Joined: Oct 2015
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408 would be an ideal drag motor with the 4” stroke, the extra arm will help pick your car up and move it from a standing start position, which is big part of what you’re doing. Don’t be timid about putting compression in it either, a cam with 25* or more degrees of overlap and a real good set of heads are the ticket. Just stay away from LS6 intakes, 243 heads and all the other inexpensive internet wonders that have serious limitations that so many put on their 408s, 575rwhp will take a max effort build with 1.4 hp at the tire per cubic inch.
I am gonna go with +5cc pistons 62cc heads or smaller. I am gonna run what I have and see how close I am. Then upgrade as needed.
I have PRC 237 heads super vic accufab. If this stuff doesnt get me there I will sell it all and move to small bore LS7 heads and CID intake.
My 370 made 500 NA on the dyno and 740 on a 150 shot on the dyno, Dyno wouldnt hold it when tried to the up the HP after that.
I am really after 575 NA. Currently if I run a 100 shot it runs 9.8s to 9.9s. I dont want to be in the 9s on motor.
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Joined: Apr 2016
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From: Lincoln, NE
408 would be an ideal drag motor with the 4” stroke, the extra arm will help pick your car up and move it from a standing start position, which is big part of what you’re doing. Don’t be timid about putting compression in it either, a cam with 25* or more degrees of overlap and a real good set of heads are the ticket. Just stay away from LS6 intakes, 243 heads and all the other inexpensive internet wonders that have serious limitations that so many put on their 408s, 575rwhp will take a max effort build with 1.4 hp at the tire per cubic inch.
On The Tree
Joined: Jun 2019
Posts: 184
Likes: 66
From: HTown, Texas
Thats the plan.
I am gonna go with +5cc pistons 62cc heads or smaller. I am gonna run what I have and see how close I am. Then upgrade as needed.
I have PRC 237 heads super vic accufab. If this stuff doesnt get me there I will sell it all and move to small bore LS7 heads and CID intake.
My 370 made 500 NA on the dyno and 740 on a 150 shot on the dyno, Dyno wouldnt hold it when tried to the up the HP after that.
I am really after 575 NA. Currently if I run a 100 shot it runs 9.8s to 9.9s. I dont want to be in the 9s on motor.
I am gonna go with +5cc pistons 62cc heads or smaller. I am gonna run what I have and see how close I am. Then upgrade as needed.
I have PRC 237 heads super vic accufab. If this stuff doesnt get me there I will sell it all and move to small bore LS7 heads and CID intake.
My 370 made 500 NA on the dyno and 740 on a 150 shot on the dyno, Dyno wouldnt hold it when tried to the up the HP after that.
I am really after 575 NA. Currently if I run a 100 shot it runs 9.8s to 9.9s. I dont want to be in the 9s on motor.
Thread Starter
TECH Apprentice
Joined: Oct 2015
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FYI it will be a minimum of 13:1 I am shooting for 13.5:1 or 14:1.
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Did you consult with TSP at all in regards to whether this head will be optimal or not? They have all the tech data on the ports for the head so they can run the numbers and find what works best with your combo.