454 Stroke?
Thread Starter
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
454 Stroke?
How far can I practacally take a Mark IV Gen 1 454 block as far as stroke. My goal is low end torque from 1500 to 5000 RPM's.
I have the 781 iron heads with bigger valves.
XE68h cam w/ roller rockers.
Will have a dual quad edelbrock on top.
Thanks in advance,
Sly
I have the 781 iron heads with bigger valves.
XE68h cam w/ roller rockers.
Will have a dual quad edelbrock on top.
Thanks in advance,
Sly
Safety Car
Joined: Aug 2006
Posts: 4,102
Likes: 1
From: Forsyth Illinois
I have a 496 here that I ran in a jet boat that I had.Steel 65 vette 396/425 horse heads w/bigger valves,and massaged by one of the best heads guy in the US.Radical solid lift cam.Roller rockers,stud girdle,Team G,and 750 DP.It's going in a 68 convertible here,but when it was in my 21 foot jet boat w/berkley jet pump...I ATE brand new 502 Bajas for lunch.They didn't have a chance!
I will say the Baja owner did have some pretty nice bikini clad young rascals hanging around over in the party cove tho'.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
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From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
I think 4.25 is about the end of it. A least in economic terms. At 4.25 you'll need to check clearance between the pan rails and the bottom of the cylinders and possibly do some grinding. Past that, any more and it'll probably take some pretty exotic stuff.
Drifting
Joined: Oct 2005
Posts: 1,527
Likes: 148
From: East London/SW Essex UK
+.060" goes 496, +.100" (if block will take it) goes 502 ish. Use a 4.375" crank (if you can get one) and grind crank clearance and you can squeeze 505 to 515 ish.
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
Here is a 4.375 stroke kit, which is pretty much the stroke limit with a low deck block.
http://cgi.ebay.com/ebaymotors/NEW-B...QQcmdZViewItem
This kit and the cam you mentioned wouldnt be a good match though.
The DCR would be over 8.5 which is unlikely to work with pump gas.
http://cgi.ebay.com/ebaymotors/NEW-B...QQcmdZViewItem
This kit and the cam you mentioned wouldnt be a good match though.
The DCR would be over 8.5 which is unlikely to work with pump gas.
Race Director
Joined: Feb 1999
Posts: 16,978
Likes: 7
From: In Dreams There Is Truth Ohio
you will have to notch the bottom of the cylinders to clear the rods, that is a given...
Safety Car
Joined: Aug 2006
Posts: 4,102
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From: Forsyth Illinois
Melting Slicks
Joined: Jan 2003
Posts: 2,877
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From: Doha
St. Jude Donor '08
Not to hi-jack, but I really would like to see some pictures of these notches needed for a 4.25 stroke, I got a couple of Mk IV 454 blocks laying around, and I got a 496 build idea in my mind for a while now, just I cant figure how to notch the end of the cylinders.
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Race Director
Joined: Feb 1999
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From: In Dreams There Is Truth Ohio
install the crank and bearings torque to specs, install one piston w/bearing, torque to spec...slowly rotate the crank and where the rod meets the bottom of the cyl, that's where you notch...until you have clearance...dremmel works good, but don't go wild with the grinding...small amounts at a time...do one cyl at a time....
'Pics won't tell you how much you have to grind...
'Pics won't tell you how much you have to grind...
Thread Starter
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
I am using 4 bolt mk4 +.030" 454 with 4.25" crank = 489 cu in. With Brodix RRO Heads, mild hyd cam, 950 cfm & Air Gap Inlet power band starts at 1200 rpm and dyno's 565 ft/lbs @ 3800 rpm. Gives 528 bhp @ 5850 rpm.
+.060" goes 496, +.100" (if block will take it) goes 502 ish. Use a 4.375" crank (if you can get one) and grind crank clearance and you can squeeze 505 to 515 ish.
+.060" goes 496, +.100" (if block will take it) goes 502 ish. Use a 4.375" crank (if you can get one) and grind crank clearance and you can squeeze 505 to 515 ish.
Here is a 4.375 stroke kit, which is pretty much the stroke limit with a low deck block.
http://cgi.ebay.com/ebaymotors/NEW-B...QQcmdZViewItem
This kit and the cam you mentioned wouldnt be a good match though.
The DCR would be over 8.5 which is unlikely to work with pump gas.
http://cgi.ebay.com/ebaymotors/NEW-B...QQcmdZViewItem
This kit and the cam you mentioned wouldnt be a good match though.
The DCR would be over 8.5 which is unlikely to work with pump gas.
Would have picked it up in pre-assembly anyway.
Sly
Last edited by sly vette; Dec 22, 2008 at 01:01 PM. Reason: STOOPID!!!
Race Director
Joined: Feb 1999
Posts: 16,978
Likes: 7
From: In Dreams There Is Truth Ohio
Don't take their word for it...check out the rod to block clearance...one cyl at a time
Melting Slicks
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
install the crank and bearings torque to specs, install one piston w/bearing, torque to spec...slowly rotate the crank and where the rod meets the bottom of the cyl, that's where you notch...until you have clearance...dremmel works good, but don't go wild with the grinding...small amounts at a time...do one cyl at a time....
'Pics won't tell you how much you have to grind...
'Pics won't tell you how much you have to grind...
So its only a minor clearance problem which can be handled with a hand dremel tool? .. thats good, I thought it was a machine-shop grade modification. Thanks.
Pro
Joined: Jan 2006
Posts: 548
Likes: 0
install the crank and bearings torque to specs, install one piston w/bearing, torque to spec...slowly rotate the crank and where the rod meets the bottom of the cyl, that's where you notch...until you have clearance...dremmel works good, but don't go wild with the grinding...small amounts at a time...do one cyl at a time....
'Pics won't tell you how much you have to grind...
'Pics won't tell you how much you have to grind...
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
Safety Car
Joined: Aug 2006
Posts: 4,102
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From: Forsyth Illinois
I got wrapped up yesterday delivering Angel tree gifts,then the wife took me out for my B-day last night....YEH!!!!
Here's the pics of the bottom end of the stroker w/the block notched for clearance.
Here's the pics of the bottom end of the stroker w/the block notched for clearance.
Safety Car
Joined: Aug 2006
Posts: 4,102
Likes: 1
From: Forsyth Illinois
Mark...it is expensive,but the guy that did the head work on these 65 396/425 horse heads has been in several articles,and was making MORE horsepower after his finesse w/iron heads,than the out of the box high dollar aluminums for guys needing iron heads in their different racing classes.This isn't wishful thinking.This is dyno runs to compare.He's up by Chicago.Super nice guy.The receipt here for the heads is 1483,and some change w/out the Crane roller rockers,and stud girdle.....
Thread Starter
Safety Car
Joined: Oct 2005
Posts: 3,570
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From: Algonac Michigan
