It's bored!!!

Bigtim44

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The 70 'block that I have sacrificed for the 502 chevy pistons and 7 inch olds rods is now bored out,damn them holes look big :yikes:,well there's no going back now!!
  He has also 2/3 filled the water jackets with that expanding anchoring cement(rocktite brand),he is going to let it cure for a week or so then finish hone it to the pistons
   This engine is being built entirely from ideas taken from this board and advice from it's members...Dave Brode it's all your fault,.....planting the seed idea. :D
  I'll get some pic's taken so you guys can see how much meat has gone from the cylinder walls. :eyepopping:
 

dave brode

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Tim,

Did you use flat, dished, or domed? What heads will you use?
Good job.
Dave


Bigtim44 said:
The 70 'block that I have sacrificed for the 502 chevy pistons and 7 inch olds rods is now bored out,damn them holes look big :yikes:,well there's no going back now!!
  He has also 2/3 filled the water jackets with that expanding anchoring cement(rocktite brand),he is going to let it cure for a week or so then finish hone it to the pistons
   This engine is being built entirely from ideas taken from this board and advice from it's members...Dave Brode it's all your fault,.....planting the seed idea. :D
  I'll get some pic's taken so you guys can see how much meat has gone from the cylinder walls. :eyepopping:
 

Bigtim44

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going with flat tops(probe),havn't decided on which heads to go for ,I don't know enuf about the clearance issues with the 76cc heads especially with big valves.therefore shaved 120's might be a better route.
 
A

Anonymous

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Good Deal !!!

I've been intrigued with this idea. Really looking forward to following your progress.

If you can. Please take a lot of pics & post 'em up.

~JM~
 

Maddog

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Whcih size rings are you using? Brand? Any coatings on the pistons? And your block has the notches in the pan rail for the rods right? What a nice project. Maddog
 

dave brode

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Tim,

Afaik, depends largely on lsa. Not sure if peak lift matters as much. Could be wrong though.
Maybe others will comment.
Dave



Bigtim44 said:
going with flat tops(probe),havn't decided on which heads to go for ,I don't know enuf about the clearance issues with the 76cc heads especially with big valves.therefore shaved 120's might be a better route.
 

dave brode

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Maddog,

OEM olds 7" require enlarging the notches at bottom of bore. Pan rail is ok.
Dave

link=topic=347.msg3757#msg3757 date=1102472774]
Whcih size rings are you using? Brand? Any coatings on the pistons? And your block has the notches in the pan rail for the rods right? What a nice project. Maddog
 

Bigtim44

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I was going to get hastings moly rings(if they do them in that size!?),unless there is a better brand at a comparative price.
I won't be doing any coatings on the pistons
 

Maddog

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So whats the pin height on these 502 pistons Dave? I am surprised there are no clearance issues. Good to know. Charles
 

cadillac512

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 :thumbup: :yes:  Good deal,Tim!  My kind of build-just oddball enough to be interesting,and to amaze and confuse those who are foolish enough to ask "What did you do to the motor?" :yikes: If you run a cam big enough to really feed this engine,you are going to want some valve reliefs for 76cc heads.I have been doing quite a bit of ciphering on this subject,and looks to me like if you get much over .550 lift you should cut at least a .100" relief. Like Dave said,a wider lobe sep will help,but no sense cutting it too close.120cc heads will have a mile of clearance no matter what cam you run.
   What are your plans for this engine?
     Terry (very jealous... :D)
 
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Anonymous

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You might want to seal off that rocktite with some devcon epoxy to keep the water/coolant from degrading it.
Should be a good runner. JW
 

MOCRUZN

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Please say what head gaskets you will use. I was under the impression this bore size presented gasket choice difficulties.

Thanks,
          Miles
 
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Anonymous

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Sounds like a nice build, i WAS JUST LOOKING AT THOSE BBC 502 pistons/ 7 inch olds rod combo  :thumbup: lol
 
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Anonymous

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I can now buy the corteco gaskets without fire rings and have done 2 sets with 4.466/4.51 ID
they arent cheap but since the cortecs are the only gasket ive never had any trouble out of it seemed like a wise choice.
JW
 

MOCRUZN

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Comp Ht on KB-175 Chev 502 is 1.645" (19cc dish), KB-173 is same ch with3cc/flat top.

Miles
 

Bigtim44

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What's involved in doing the copper head gaskets ?,this will be a race only motor therefore I might want to re-use gaskets especially out on the salt flats away from the workshop.
 

Sean

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O-ringing the block and putting silicone in the right places on the headgasket when assembling. Throw some of those GM cooling system sealing tablets in before you start it and it should be good to go. Its a little more hassle than a normal gasket but not to bad.

Can't remember how deep or wide to cut the groove for sure but .020 deep for a .030 wire comes to mind.
 

dave brode

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Charles,
As Miles noted, KB's 502s are same as their 454s. Most other brands are close to that.
Dave

Maddog said:
So whats the pin height on these 502 pistons Dave? I am surprised there are no clearance issues. Good to know. Charles
 

dave brode

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JW,

Are you modifting the Cortecos yourself, or having them done? IIRC, they are 4.385" on the normal ones.
An option for a big bore would be great.
Dave
 

dave brode

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Tim,

IIRC, the Probes are standard rings [1/16" or 5/64?]. The GM JE700s are a weird metric ring, and very pricey. The GM pistons are out there cheap, but the ring cost make them look less good. SRP makes the same piston except for a std ring pack.

As far as ring mat'l, I like a ductile iron top, rather than a cast, in either plain [flame proof suit on], or moly filled. Most experts seem to like plasma moly these days. I don't know what the diff is.

A note on rings - I have an 4.125"bore 11.5-1CR Harley engine with short cams that I pinged hard, and the moly fill in the rings was gone when later pulled it down to have a look. The only thing sitting against the walls was the grooves between which the moly is sprayed. I know I'm not supposed to let the thing ping, but I was tuning [not too carefully]. I put ductile iron plain back in [speedpro]. It still seals up ok.
Dave


Bigtim44 said:
I was going to get hastings moly rings(if they do them in that size!?),unless there is a better brand at a comparative price.
I won't be doing any coatings on the pistons
 
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