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Twin turbo 401

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htrdkd69 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote htrdkd69 Quote  Post ReplyReply Direct Link To This Post Topic: Twin turbo 401
    Posted: Feb/20/2018 at 11:59pm
Hello im wanting to build my 40 over 401 for twin hx35 turbos and I was wondering if a studed 2 bolt main with factory rods will hold up I wont be running real high psi going to try to keep it under 10 any information would be great
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mixed up Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2018 at 12:27am
the amc bigger cubic inch motors are a very strong group all have steel rods and cranks and will put up with a lot of abuse as long as your not beating on it every week end there should be no problem with your idea
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htrdkd69 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote htrdkd69 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2018 at 12:51am
Would cast pistons be ok to run ? Im have harlen sharp rocker would I need a Girdle for them and would a rv cam be ok ?

Edited by htrdkd69 - Feb/21/2018 at 12:58am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote SirDigger Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2018 at 1:37am
For a Turbo (even with low boost] you´ll need to lower the normal ratio anyway..
So you´ll need new pistons anyway, and i wont cheap out on pistons..
SirDigger&his german Friends are looking for Parts http://theamcforum.com/forum/the-german-amc-forum-ambassadorsirdigger-needs_topic83570.html
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htrdkd69 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote htrdkd69 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2018 at 9:21am
My 401 is a 77 block I've read that the later 401 are 8.25 to 1 what pistons would you recommend? Ive seen some 27.5 cc forged speedpro pistons there dish would something like that work ?

Edited by htrdkd69 - Feb/21/2018 at 9:36am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote shootist Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2018 at 1:42pm
40 over with 10lbs is asking to blow out a cylinder wall. I would sleeve the block or go no more than .020-.030 over without sleeving.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AMXRWB Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2018 at 2:32pm
The best way to go is no over bore if you want to run an engine under boost.  
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Feb/22/2018 at 6:55am
I wouldn't run a 0.040" over 401 block with boost, nitrous, or even 11:1 compression. AMC only recommended a 0.020" overbore on the 401 block. I wouldn't go over 0.030", and if planning on running something that boosted cylinder pressure over what a 10:1 compression ratio would, I'd have it sonic checked for good sidewall thickness. If you plan on running boost you should sleeve that block down to a 360 bore or something you can find pistons for. That or use a 360 block. You will be best off with forged pistons, but at least hyperuetectic (spelling probably not right!) cast type. I wouldn't use standard cast pistons for something you plan on running hard or with high power. Not unless this is going to be a trailer queen show car that will never really be run hard.
Frank Swygert
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Post Options Post Options   Thanks (0) Thanks(0)   Quote texasamx Quote  Post ReplyReply Direct Link To This Post Posted: Mar/01/2018 at 8:51pm
If you want to boost  a 401 you really need as strong an  engine bore as possible with little or no over bore.  also  forge pistons are a must  if you want the engine to live  . 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Mar/02/2018 at 6:39am
Stick with a 360 block, or even a 304. Boost will somewhat make up for loss of cubes. I don't think bottom end will be an issue with either, but if you could find a virgin SR block that would be best -- 401 webbing, 360 bore. 
Frank Swygert
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