If I use 5.7" rods in a 400 w400 crank, will I have clearance problems?
Supreme Member
Joined: Jul 1999
Posts: 18,457
Likes: 16
From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
That would depend on what pistons you use. If you put stock 400 pistons in there, they will poke out the top of the block about .125", so there will be a minor clearance issue between the pistons and the heads. Other than that, no problem.
They do make pistons for that combo, but they're not cheap.
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"So many Mustangs, so little time..."
ICON Motorsports
They do make pistons for that combo, but they're not cheap.
------------------
"So many Mustangs, so little time..."
ICON Motorsports
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Joined: Jul 1999
Posts: 17,262
Likes: 168
From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
The aftermarket pistons move the wrist pin up into the oil control rings.
There's nothing wrong with using the 400's 5.56" rods. Polish the beams and install ARP bolts.
The 5.7" rods need to use the 400's style of rod bolts and clearances need to be checked at the bottom of the cylinder and at the cam.
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Follow my racing progress on Stephen's racing page
and check out the race car
87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block (times are for the current engine)
Best ET on a time slip: 11.447 altitude corrected to 10.99
Best MPH on a time slip: 119.42 altitude corrected to 124.86
Altitude corrected rear wheel HP: 493
Best 60 foot: 1.586
Racing at 3500 feet elevation with a typical race day over 5000 feet density altitude!
Member of the Calgary Drag Racing Association
87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley
There's nothing wrong with using the 400's 5.56" rods. Polish the beams and install ARP bolts.
The 5.7" rods need to use the 400's style of rod bolts and clearances need to be checked at the bottom of the cylinder and at the cam.
------------------
Follow my racing progress on Stephen's racing page
and check out the race car
87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block (times are for the current engine)
Best ET on a time slip: 11.447 altitude corrected to 10.99
Best MPH on a time slip: 119.42 altitude corrected to 124.86
Altitude corrected rear wheel HP: 493
Best 60 foot: 1.586
Racing at 3500 feet elevation with a typical race day over 5000 feet density altitude!
Member of the Calgary Drag Racing Association
87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley
Member
Joined: Oct 2000
Posts: 223
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From: way over there
Car: 87 IROC
Engine: LB9 for the moment
Transmission: T5
if I remeber correctly the rod journals for a 400 crank are larger than the 350 journals so you may have to have the rod journals cut down for the 5.7 rod unless you go w/ an aftermarket custom rod...
zroc
zroc
Steve's right. Also, if you use 5.7" rods you use standard rod bolts, not 400-style. They're totoally different bolts and they are not interchangable. Yes, you will have possibly some clearance issues at the bottoms of the bores where the rod bolt nut will come close to striking (not nearly as big a deal as it would be if you were building a 383 from a 350 block, though). Also, the HEAD of the rod bolt may have interferece problems with a few of the cam lobes, but this varies from cam to cam so it's difficult to say for sure.
Again, this is minor-league grinding compared to building a 383 with 5.7" rods.
Again, this is minor-league grinding compared to building a 383 with 5.7" rods.
stick to a 5.7rod or 6"rod and go with aftermarket pistons. shorter rods have increase rotational angles from the wrist pin to the crank journal. longer rods are better, just searh any stroker website.
i just built a 383 complete with all the goodies.
i just built a 383 complete with all the goodies.
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Supreme Member
Joined: Aug 1999
Posts: 1,443
Likes: 0
From: College Station, Tex USA
Car: 89rs
Engine: 400Sb
Transmission: Tremec 3550
drop me email if interrested. I have a set of 030" over Kb139s (400 w/5.7 rods), that have 20 hours on them.
[This message has been edited by jcb999 (edited November 21, 2001).]
[This message has been edited by jcb999 (edited November 21, 2001).]
Joined: Feb 2001
Posts: 752
Likes: 19
From: Westminster, MD USA
Car: 91 Firebird 'vert, 91 Formula
Engine: 5.7, 5.0
Transmission: T56, T5
Axle/Gears: Auburn w/ 3.73's, 3.42
I had a 406 in my old 84 SS monte. 400 + .030". I was running stock (reconditioned) 5.7 rods w/ KB 125 pistons (10.1 compression w/ 76cc heads-fairly inexpensive but nice). The rods did need some grinding for block clearance by the rod bolts (don't remember exactly where b/c it's been 4 years) but it was nothing major. Your machine shop would figure it out I'm sure when doing the machine work & balancing. Also, as mentioned above, you need 5.7 rod bolts, the 400's are to short (I remember finding out the hard way). It's an awesome way to go....awesome displacement, power range & performance. The motor dyno'd around 460hp @ 6200RPM's & 450lbs. of torque @ 3500RPM's (guess-tamits based on memory, got specs at home somewhere) making it an incredible street motor!!! Drop me a line if you want more info...I still have all the paper work & specs on the motor.
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'91 Z28 1LE; 355, Sportsman II heads, Edelbrock TPI w/ 58mm TB, Tremec TKO 5-speed, 3.73's & much, much more
[This message has been edited by Ed1LE (edited November 21, 2001).]
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'91 Z28 1LE; 355, Sportsman II heads, Edelbrock TPI w/ 58mm TB, Tremec TKO 5-speed, 3.73's & much, much more
[This message has been edited by Ed1LE (edited November 21, 2001).]
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