My 406 CI Engine Buildup!
Thread Starter
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
My 406 CI Engine Buildup!
Thought some of you guys would like to see the buildup of my 406 that we started yesterday. Took us about 6 hours to get up to the heads. Should be able to get it painted, and ready to drop in the car this week.
Let me know what you think. :cheers:
Here is the link to the first of five posts.. http://forums.corvetteforum.com/zerothread?id=471013
Let me know what you think. :cheers:
Here is the link to the first of five posts.. http://forums.corvetteforum.com/zerothread?id=471013
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: My 406 CI Engine Buildup! (ski_dwn_it)
I must have missed out sometime. what broke your 350 rings? You have a healthy cam are also going to install some type of stud girdle? If you are I would recomend the Crane. I did run into a fitting problem with the 7/16th rocker nuts supplied with the girdle when used with Comp and Crower cams steel rocker arms.
The locking Allen type Crane nuts were bigger than the rocker shaft machined hole. So I had a machinist buddy use his lathe to make the end of each nut a slightly smaller diameter. I was told that with 3/8th studs this isn't an issue
The locking Allen type Crane nuts were bigger than the rocker shaft machined hole. So I had a machinist buddy use his lathe to make the end of each nut a slightly smaller diameter. I was told that with 3/8th studs this isn't an issue
Thread Starter
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Re: My 406 CI Engine Buildup! (gkull)
Thanks for the comments.
I am not going to be using stud girdles. Only gonna be revving to 5600 RPM so I don't think with the ARP 7/16 studs it should be a huge concern. I have read that use of these girdles when not absolutely needed, actually caused a loss in power. :confused:
Thanks again...
Not real sure what broke the 350's rings. Every one of the top rings were broke. I honestly believe the rings were broke when I bought the car 3 yrs ago. I recently spoke with the guy that had the car and he alluded to some cylinder leakage. I can only speculate, but it almost seems like there might have been a problem right from the factory. Like to tight of ring gap. #7 cylinder's top ring was in about 15 pieces when I pulled it out. And the skirt was busted right off. :confused:
The funny thing is the engine did not use one bit of oil or show any real signs of power loss, other than at the track. The average person would have never know the difference. It still ate up camero's mustangs etc like candy on the street/strip. :p: Just wasn't doing what I thought it should. Hence the reason for the MONSTER we are building. I am hoping to get into the 10s with this setup. :cheers:
I am not going to be using stud girdles. Only gonna be revving to 5600 RPM so I don't think with the ARP 7/16 studs it should be a huge concern. I have read that use of these girdles when not absolutely needed, actually caused a loss in power. :confused:
Thanks again...
Not real sure what broke the 350's rings. Every one of the top rings were broke. I honestly believe the rings were broke when I bought the car 3 yrs ago. I recently spoke with the guy that had the car and he alluded to some cylinder leakage. I can only speculate, but it almost seems like there might have been a problem right from the factory. Like to tight of ring gap. #7 cylinder's top ring was in about 15 pieces when I pulled it out. And the skirt was busted right off. :confused:
The funny thing is the engine did not use one bit of oil or show any real signs of power loss, other than at the track. The average person would have never know the difference. It still ate up camero's mustangs etc like candy on the street/strip. :p: Just wasn't doing what I thought it should. Hence the reason for the MONSTER we are building. I am hoping to get into the 10s with this setup. :cheers:
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: My 406 CI Engine Buildup! (ski_dwn_it)
I don't even understand why someone could even think that stud girdles make a loss of power! :confused: Well maybe the bench racer that doesn't have the forethought to understand what they are good for
But anyway the rule of thumb is how much the rocker studs deflect when all the valve are set to lash spec. If you lay a metal straight edge down the side of all your 7/16th studs without rockers in place they should be straight.
Once you start cranking down to set the lash on every one of the rockers. Lay the straight edge and if the studs deflect more than .030 when your rotating the motor over your screwed too not use a stud girdle.
If your studs are bending back and forth. Your rocker tip is side loading the valves and burning up the guides. Also how strong do you think that aluminum head really is with a stud working on aluminum threads. It's more like any deflection is bad and you get the added bonus of not having to worry about your rocker nuts ever going loose.
There is a down side: Tall valve covers and the $150 Crane stud girdle
But anyway the rule of thumb is how much the rocker studs deflect when all the valve are set to lash spec. If you lay a metal straight edge down the side of all your 7/16th studs without rockers in place they should be straight.
Once you start cranking down to set the lash on every one of the rockers. Lay the straight edge and if the studs deflect more than .030 when your rotating the motor over your screwed too not use a stud girdle.
If your studs are bending back and forth. Your rocker tip is side loading the valves and burning up the guides. Also how strong do you think that aluminum head really is with a stud working on aluminum threads. It's more like any deflection is bad and you get the added bonus of not having to worry about your rocker nuts ever going loose.
There is a down side: Tall valve covers and the $150 Crane stud girdle
Thread Starter
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Re: My 406 CI Engine Buildup! (gkull)
gkull,
Not real sure why they would say that?
Corky has been running his for quite some time and has had no problems, so I would imagine I will be alright too. He has pulled his covers off several time and the valve lash was still in spec.
You make some good points though.... :cheers:
Not real sure why they would say that?
Corky has been running his for quite some time and has had no problems, so I would imagine I will be alright too. He has pulled his covers off several time and the valve lash was still in spec.
You make some good points though.... :cheers:
