Heads Disassembled

[shaun]

Ok, finally got some time to disassemble the heads today. I think i got everything off. Just wanted to make sure before i started using the aircraft stripper.
http://www.reitanfamily.com/albums/HeadDisassembly/0042_G.jpg
http://www.reitanfamily.com/albums/HeadDisassembly/0048_G.jpg
http://www.reitanfamily.com/albums/HeadDisassembly/0049_G.jpg
http://www.reitanfamily.com/albums/HeadDisassembly/0029_G.jpg
http://www.reitanfamily.com/albums/HeadDisassembly/0050_G.jpg
http://www.reitanfamily.com/albums/HeadDisassembly/0038_G.jpg
http://www.reitanfamily.com/albums/HeadDisassembly/0032_G.jpg
Also, i noticed that the values have some small pits in them, should i replace the valves?
http://www.reitanfamily.com/albums/HeadDisassembly/0025_G.jpg
Sorry for the poor quality pics, they are from a web cam from 1990 :) I cant seam to find my digital cam. :hammer2:

[GofastRacer]

Shaun, that is just street stuff and who knows how much abuse is on that stuff, they were on there when I got those heads. If you're planning on any high performance at all you're asking for trouble using that stuff, keep the guide plates and replace it all with good quality parts, the motor will love ya for it!..

[victorfb]

what size valves do you have? i have a new set of stock valves for BBC. i think they are 2.19 int. not sure about the exh. i can check later this afternoon.

[shaun]

GoFastRacker: I plan on replacing the valves springs, retainers, keys/locks, etc i just wasnt sure if i should replace the valves or not. They look pretty bad, i think it's probably the best idea.
Victorfb: As far as i know the valves are stock size, but then again, i bought these from art and i dont know much about whats in them or whats been done to them. Stock on the 990's is 2.19 int and 1.88 Ex i beleive. Once i get the paint off the heads i'm taking them down to the machine shop to be checked out, i'm sure they will give me all the info i need for new valves. I'll pm you when i find out the size.
Another Q, What is a good value to put in these? It's a mild N/A BBC build and i dont plan on squeezing but i may want to in the future.

[GofastRacer]

GoFastRacker: I plan on replacing the valves springs, retainers, keys/locks, etc i just wasnt sure if i should replace the valves or not. They look pretty bad, i think it's probably the best idea.
Victorfb: As far as i know the valves are stock size, but then again, i bought these from art and i dont know much about whats in them or whats been done to them. Stock on the 990's is 2.19 int and 1.88 Ex i beleive. Once i get the paint off the heads i'm taking them down to the machine shop to be checked out, i'm sure they will give me all the info i need for new valves. I'll pm you when i find out the size.
Another Q, What is a good value to put in these? It's a mild N/A BBC build and i dont plan on squeezing but i may want to in the future.
Replace the valves I wouldn't use them in my tow vehicle, if you plan on squeezing it down the road go for the Manley "Severe Duty" valves, no sense in buying cheap ones now and later dishing out for the good ones, it'll just cost more just do it right the first time!..BTW, they are 2.19 and 1.88's!..

[Moneypitt]

If you are taking the heads to a shop for valve work, let the hot tank remove the paint!!!!!............MP

[GofastRacer]

That's what I would do!..

[shaun]

i didnt think the hottank would get all the paint off, if it will i'd rather just do that..

[Moneypitt]

The hot tanking process will take off "most" paint. If the tank doesn't take it off a rotary wire brush will usually finish the job. Let the tank do the work first, you may be pleasantly suprised. It has been years since I actually disassembled heads before taking them to a shop for valve work........MP

[GofastRacer]

i didnt think the hottank would get all the paint off, if it will i'd rather just do that..
It will, just tell them you want it all off and they will let it cook longer!..

[shaun]

can the heads be surfaced assembled?

[GofastRacer]

No, that gets done when you have it tanked and a valve job done!.

[wideopen545]

glass bead

[victorfb]

can the heads be surfaced assembled?
actually it can, but you would have to dissasemble the heads again to clean them. so what would be the point? remember, one MAJOR factor in making a motor live is to keep it clean. keep that in mind when assembling the entire motor. clean it, then clean it again, assemble each peice after cleaning them. keep your tools clean, and keep the area clean. im not a clean freak, just when it comes to assembling motors.

[shaun]

ok, i was just wondering, reason being is that once i find out if these heads are ok i need to find out what compression they are going to yeild with my block and pistons. The deck has been squared when i took the block in and who knows what was done to it before when the previous rebuild or rebuilds where done on it. Same goes with these heads. The pistons where suppose to bump me into the 10.1 range but i'm wondering if it's going to be a bit higher. If it gets to the point where i cant run pump gas i guess i might as well shave alittle off and bump the compression up a bit more.
I think i may rename my project to my 'First BBC Motor Project, done backwards' :)
I suppose i could just find out my compression now before i take the heads in that way everything can be done at once. So that brings me to my next question. How do i figure out my compression ratio with out knowing what the deck is at and how much has been taken off the heads?

[Moneypitt]

A simple check of the head casting #s will telll you what size the chambers are/were...... The BBc only has about 4 chamber sizes from the factory. The casting #s will tell you what you're dealing with, and the piston guys will tell you the CR depending on the chamber size, etc. etc. ......MP

[shaun]

Moneypit: right, the heads are 118cc stock if i recall correctly but thats what i'm wondering about. Who knows if these heads have ever been surfaced before or if somebody milled them to bump up the compression. This block has been rebuilt twice so far and not by me or my dad so i'm not sure what the deck is at.
With my current bore and stroke and a 118cc head these pistons where suppose to yeild 10.1 (dom vol 23cc).

[Moneypitt]

A few thou off the block and/or heads isn't going to change the CR by more than a few 10ths, if that. If your target was low 10s, you should still be within an acceptable range of that number.............MP

[GofastRacer]

Those heads looked like they were all original, don't look like they were cut but the ONLY way to make sure is to CC the chambers regardless if they were cut or not to make sure you know exactly what the chambers are, that's the only way you're going to know how to set up your compression!..

[GofastRacer]

With my current bore and stroke and a 118cc head these pistons where suppose to yeild 10.1 (dom vol 23cc).
But with what deck height and head gasket thickness and CC, all of this has to be taken into consideration, you need to measure all this stuff up!..

[shaun]

GoFastRacer: right, i didnt think about that stuff then, i just saw 454 .060 over with 118 CC heads made 10.1 on there chart. Since chris (cstraub69) is such a nice guy and said he would design a cam specifically for my app i need to know my exact compression. I searched google and found a nice lesson on how to calculate compression. Sounds like i need to assemble the bottom end or at least put one piston in.
http://www.chevyhiperformance.com/techarticles/46778/
If the heads havnt been touched then 118cc they should be.
I am trying to stay in the pump gas compression range. Some have told me that i'm already too high and should stay at 9.5 and some say with cast heads i can get away with 10.5.