ANY0027.jpg[/IMG]
Broken Rear Main Cap!
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I'm say that since the poster has his previously align bored main cap it would be very easy to measure it and recreate an exact duplicate out of a purchased billet main cap from a vendor like Milodon.
Race Director
Joined: Dec 1999
Posts: 11,094
Likes: 990
From: Sierra Foothills CA
The new caps are the same. the block shift would cause the cap to be in the wrong place, hence requiring the align bore.
I'm say that since the poster has his previously align bored main cap it would be very easy to measure it and recreate an exact duplicate out of a purchased billet main cap from a vendor like Milodon.
I'm say that since the poster has his previously align bored main cap it would be very easy to measure it and recreate an exact duplicate out of a purchased billet main cap from a vendor like Milodon.
As long as the bearing is properly sized to the crank (which it should be already) and the new cap doesn't distort the bearing, the tolerances should be fine.
Le Mans Master
Joined: Jan 2006
Posts: 6,505
Likes: 139
From: Butler Pa
I'll be the first to admit that I've seen a cap replaced and the person got lucky and it fit good enough to run, but that is very rare.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
It's not a courtesy service, it's required.
When a new block is machined, the caps are installed and the block is line honed, therefore no 2 will be exactly alike. There's too many tolerances involved.
I'll be the first to admit that I've seen a cap replaced and the person got lucky and it fit good enough to run, but that is very rare.
When a new block is machined, the caps are installed and the block is line honed, therefore no 2 will be exactly alike. There's too many tolerances involved.
I'll be the first to admit that I've seen a cap replaced and the person got lucky and it fit good enough to run, but that is very rare.
Le Mans Master
Joined: Jan 2006
Posts: 6,505
Likes: 139
From: Butler Pa
And I'm saying, that's not going to happen without line honing it on the block, unless you're going to pay thousands of dollars to have it machined.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
i have access to a cnc 3 axis machine that could take computer controlled measurments to the strictest of measurments, and make me one out of what ever metal i want..
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Thread Starter
Pro
Joined: May 2009
Posts: 569
Likes: 2
From: Clio Mi
Ok, hi guys.. this is what im going to do..
Im going to pull the motor buy new main caps from milidon forged splayed.
The machine shops i deal with said this would be best.. they also said the three axis machine would work to but the cost is about the same as pulling the motor and redoing the mains,,, response was "If it was My motor i would pull it" im going to listen to them... if i had a couple grand into a run of the mill engine i would probly opt for the reweld bandaid, or new cap. but like i said im at about 13 thousand on this thing so whats another 2,200 to ensure drivability for another 200,000Miles (praying on knees)... its just a sad day in the Neptune's Corvette world... Thanks for the responses and support guys!!!
Im going to pull the motor buy new main caps from milidon forged splayed.
The machine shops i deal with said this would be best.. they also said the three axis machine would work to but the cost is about the same as pulling the motor and redoing the mains,,, response was "If it was My motor i would pull it" im going to listen to them... if i had a couple grand into a run of the mill engine i would probly opt for the reweld bandaid, or new cap. but like i said im at about 13 thousand on this thing so whats another 2,200 to ensure drivability for another 200,000Miles (praying on knees)... its just a sad day in the Neptune's Corvette world... Thanks for the responses and support guys!!!
Thread Starter
Pro
Joined: May 2009
Posts: 569
Likes: 2
From: Clio Mi
I bought the Hoist used From a Chrysler Dealer ship that was going out of business for 800.00 What a steel!!!! 7000k lifting capacity,, oxy acetylene hose reel,compressed air hose reel, light reel, power cord reel,
diamond plate ramp and breaker and wire upgrade ,hydrolic fluid and some misc extras puts me at 1300 ish dollars... I love it... you guys keep a close eye on Chrysler if they go another billion in debt im sure we will all have some hoist in our garages...
diamond plate ramp and breaker and wire upgrade ,hydrolic fluid and some misc extras puts me at 1300 ish dollars... I love it... you guys keep a close eye on Chrysler if they go another billion in debt im sure we will all have some hoist in our garages...
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Thread Starter
Pro
Joined: May 2009
Posts: 569
Likes: 2
From: Clio Mi
Damn this sux Neptune....sorry to hear this for you...
Is the cap completely broken? Just a single crack at the seal area? Post up some pics..... If it's just a crack on the outer edge and not that long, I might would try to braze/cast weld it and run the damn thing.....
Ofcourse the "right" way to fix it is a tear down, new cap, line bore and new blueprinted main bearings but.....depending on the cracks size/location.....I may either just leave it or attempt to weld it....if it's only in the seal area etc....although that sucker is just bound to leak...(the seal)...
Aj, im so sick of hearing "looks like your gunna need ANOTHER couple thousand"
i feel like selling the damn thing and buying a c5 or c6 with a Gdamn warrenty.....
i think i read some whare you are a weld inspector...??
I hope you get it fixed....if it makes you feel better, I frag'd my fresh built TH400 last weekend and have to pull the tranny out for a full teardown.....rebuild etc...$1500 down the tubes.
Is the cap completely broken? Just a single crack at the seal area? Post up some pics..... If it's just a crack on the outer edge and not that long, I might would try to braze/cast weld it and run the damn thing.....
Ofcourse the "right" way to fix it is a tear down, new cap, line bore and new blueprinted main bearings but.....depending on the cracks size/location.....I may either just leave it or attempt to weld it....if it's only in the seal area etc....although that sucker is just bound to leak...(the seal)...
Aj, im so sick of hearing "looks like your gunna need ANOTHER couple thousand"
i feel like selling the damn thing and buying a c5 or c6 with a Gdamn warrenty.....
i think i read some whare you are a weld inspector...??
I hope you get it fixed....if it makes you feel better, I frag'd my fresh built TH400 last weekend and have to pull the tranny out for a full teardown.....rebuild etc...$1500 down the tubes.
Thread Starter
Pro
Joined: May 2009
Posts: 569
Likes: 2
From: Clio Mi
My vette is a 1975, Dark Steel Blue Metalic . original color with silver interior..
Thread Starter
Pro
Joined: May 2009
Posts: 569
Likes: 2
From: Clio Mi
Drifting
Joined: Dec 2005
Posts: 1,360
Likes: 3
From: NORTHEAST
Rear caps can be a pain because the thrust has to be cut in and the rear seal has to be cut is.
Some times you can find a another cap that might be close enongh to line hone in but its a long shot be cause over the years I have learned GM doesn not drill the same hole twice in the same spot!!
Drifting
Joined: Dec 2005
Posts: 1,360
Likes: 3
From: NORTHEAST
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
BLOCKMAN, I have a question for you, We had a Ford racing motor in the other day and it came with a main cap girdle. Is that more common on ford blocks than chevy?
Drifting
Joined: Dec 2005
Posts: 1,360
Likes: 3
From: NORTHEAST
You are right I forgot that the us doesn't make steel any more! I went looking for billet main caps and Eagle seems to come up.
BLOCKMAN, I have a question for you, We had a Ford racing motor in the other day and it came with a main cap girdle. Is that more common on ford blocks than chevy?
BLOCKMAN, I have a question for you, We had a Ford racing motor in the other day and it came with a main cap girdle. Is that more common on ford blocks than chevy?
The girdle mignt help from front to rear but does absolutly nothing as far as making the caps stronger as these ones were still flexing.
The Dart SHP Ford blocks come with billet caps and thats the way to go!!
