Heads

[HAceT]

I thought of something last night and figured I'd ask here. As some may know my 400sbc has I believe a cracked head. I'll know for sure soon. If it does I was looking at some aluminum heads but with Christmas and other things going on I really don't want to spend that kind of money now but I do want to get the car back going....(and so does my family). I have a set of 305 HO heads that are on the 327 and they have been port and polished. They have 1.95 I / 1.5 E in them. Will they work if I drill the steam holes. ( of course I hear some say that as long as you got a good cooling system then you wont need the holes, and with the new radiator even with a blown head I am running 160 max. This is just a thought since I am getting pressure to put the car back on the road and I don't want to spend alot of money at this time.

 

[RPM]

I thought of something last night and figured I'd ask here. As some may know my 400sbc has I believe a cracked head. I'll know for sure soon. If it does I was looking at some aluminum heads but with Christmas and other things going on I really don't want to spend that kind of money now but I do want to get the car back going....(and so does my family). I have a set of 305 HO heads that are on the 327 and they have been port and polished. They have 1.95 I / 1.5 E in them. Will they work if I drill the steam holes. ( of course I hear some say that as long as you got a good cooling system then you wont need the holes, and with the new radiator even with a blown head I am running 160 max. This is just a thought since I am getting pressure to put the car back on the road and I don't want to spend alot of money at this time.

The 400 and 350 heads have 76cc combustion chambers while the 305 has 58cc chambers. The heads will bolt on and run, but it is going to really raise the compression ratio.That will raise the ratio about 2 full points. Which is probably way too much. Taking it from 9-1 to about 11-1

 

[HAceT]

When the 1.95 valves were put in they had to cut reliefs out of the side of the chamber to allow more flow around the valve. But I bet it still aint enough to help lower the compression. I have the money to get those heads you told me about but man it's right here near Christmas...

 

[Screaming Metal]

Heres what you could do....since you have the heads off, and you can take there heads back to the shop....tell them your situation, they can get a 'bowl wheel', Ron knows what I'm talking about, it made for putting oversize valves in small combustion chambers, drop the wall straight down to the top of the valve seat....more or less 'unshrouding' that valve. It would lower you compression ratio slightly, plus increase flow a little bit. That, along with a THICK head gasket, will help you some....possibly getting you back to about 9.5 or 10.0 to 1....instead of 11.

Fel-pro makes several diff. thicknesses of gaskets....go with the thickest you can find. If your intake has been port-matched, the floor of your intake would now be slightly lower....but for the street, performance shouldn't be adversely affected........

Also....if you had them smooth the combustion chamber.....or you could, thats removing a slight amout of material, lowering your ratio.
You could also 'fire-trench' the top of your pistons, if your really into wrenching and motors.....but I'd only feel comfortable letting a seasoned pro do this....one slip of the grinder and you could mess a cylinder wall up or a deck surface....but the performance gains would well be worth it.....
Just my 2 pecos....

 

[RPM]

Heres what you could do....since you have the heads off, and you can take there heads back to the shop....tell them your situation, they can get a 'bowl wheel', Ron knows what I'm talking about, it made for putting oversize valves in small combustion chambers, drop the wall straight down to the top of the valve seat....more or less 'unshrouding' that valve. It would lower you compression ratio slightly, plus increase flow a little bit. That, along with a THICK head gasket, will help you some....possibly getting you back to about 9.5 or 10.0 to 1....instead of 11.

Fel-pro makes several diff. thicknesses of gaskets....go with the thickest you can find. If your intake has been port-matched, the floor of your intake would now be slightly lower....but for the street, performance shouldn't be adversely affected........

Also....if you had them smooth the combustion chamber.....or you could, thats removing a slight amout of material, lowering your ratio.
You could also 'fire-trench' the top of your pistons, if your really into wrenching and motors.....but I'd only feel comfortable letting a seasoned pro do this....one slip of the grinder and you could mess a cylinder wall up or a deck surface....but the performance gains would well be worth it.....
Just my 2 pecos....

This all true and some good advice, but. Why spend more money on a set of heads that really won't perform. If Wayne had free access to a machine shop and could do all that for free then yes it would be a good way to go. I would be that would cost about $400 to have all that done at a shop. Figuring 8 hours work at $50 an hour.

I am still saying go for the new heads.

 

[HAceT]

Well I did an old school trick and found Sodium silicate and poured it into the radiator and fired it up and ran it. I had one heck of a time getting her to 190. I don't believe and can be so bad since she runs soo cool. My missing problem was the distrib that was rebuilt twice. I just bought a new one anit runs smooth as heck. With the stuff in the water it appears to of worked very well. I had to get the car to 4,500rpms for it to warm upto 180. I drove it in 2nd gear that way for about 5 miles. I have driven the car about a total of 40 miles and she seems to be holding good. It's an old school trick that if you research it tells you about it working wonders. Now I also found that it is a key ingredient in Bars Leak. Go figure. They also pour it in engine oil to sieze up the blocks so it can't be reused per the cash for clunkers deal. I just hope it holds past the holidays and then I might go with the new heads.

 

[Screaming Metal]

Hey, I'm glad that worked out for ya! Good Going! Ron, your right....sometimes I forget :thinkn: I've got alot of equipment....anyway....yes....better for spending the money on something that you'll definitely see benefits with. Plus running cooler and a real weight savings to boot!

 

[Wild Mango]

Well I did an old school trick and found Sodium silicate and poured it into the radiator and fired it up and ran it. I had one heck of a time getting her to 190. I don't believe and can be so bad since she runs soo cool. My missing problem was the distrib that was rebuilt twice. I just bought a new one anit runs smooth as heck. With the stuff in the water it appears to of worked very well. I had to get the car to 4,500rpms for it to warm upto 180. I drove it in 2nd gear that way for about 5 miles. I have driven the car about a total of 40 miles and she seems to be holding good. It's an old school trick that if you research it tells you about it working wonders. Now I also found that it is a key ingredient in Bars Leak. Go figure. They also pour it in engine oil to sieze up the blocks so it can't be reused per the cash for clunkers deal. I just hope it holds past the holidays and then I might go with the new heads.

Happy news!. BTW you really need the "steam" holes in heads run on siamesed bores like the 4 1/8" SBC's. Without the holes you can get air/steam pockets and localised overheating = cracksville, bad place to visit. IMHO 1.94" / 1.6" valves are as good as 2.02 / 1.6 for the street and can actually flow a bit more because the bigger inlet shrouds worse in GM heads. (Screamin' what you reckon, mate?)

 

[Screaming Metal]

Happy news!. BTW you really need the "steam" holes in heads run on siamesed bores like the 4 1/8" SBC's. Without the holes you can get air/steam pockets and localised overheating = cracksville, bad place to visit. IMHO 1.94" / 1.6" valves are as good as 2.02 / 1.6 for the street and can actually flow a bit more because the bigger inlet shrouds worse in GM heads. (Screamin' what you reckon, mate?)

yup, they're called steam holes for a reason.... k: ... 1.94's are good, and will give great performance....2.050's without the correct cam, headers and intake will hinder performance. Port velocity drops way down, clogging things up. Another thing, besides valve lift, it the big valve doesn't have a big port....thats just as bad. :thumb:

 

[HAceT]

Yeah the steam holes are there. The heads were 400 heads. I want to Thank everyone for their advise. I just gave up and had to take a step back before I did anything I'd regret... :suicide:

 

[Screaming Metal]

Sometimes too much information is just as bad as no information.....sorry for confusing info....we try to give you the info so you can make a informed decision. As long as things are good with your motor, your good. Winters closing in, if it should ever get here....you could pull them and check them out...
Just my 2 pecos....

 

[RPM]

Well I did an old school trick and found Sodium silicate and poured it into the radiator and fired it up and ran it. I had one heck of a time getting her to 190. I don't believe and can be so bad since she runs soo cool. My missing problem was the distrib that was rebuilt twice. I just bought a new one anit runs smooth as heck. With the stuff in the water it appears to of worked very well. I had to get the car to 4,500rpms for it to warm upto 180. I drove it in 2nd gear that way for about 5 miles. I have driven the car about a total of 40 miles and she seems to be holding good. It's an old school trick that if you research it tells you about it working wonders. Now I also found that it is a key ingredient in Bars Leak. Go figure. They also pour it in engine oil to sieze up the blocks so it can't be reused per the cash for clunkers deal. I just hope it holds past the holidays and then I might go with the new heads.

I had a SBC 400 in a Suburban that we towed with. It cracked a head right in the middle of racing season one year and did the silicate trick to it. It held for about 3 years with no problem.

 

[HAceT]

Sometimes too much information is just as bad as no information.....sorry for confusing info....we try to give you the info so you can make a informed decision. As long as things are good with your motor, your good. Winters closing in, if it should ever get here....you could pull them and check them out...
Just my 2 pecos....

Hey Screaming Metal, I didn't take anyones advise the wrong way. Heck I welcome all advise. I'm sorry if my post seemed sarcastic because thats far from what I meant. I enjoy this site too much and the advise from others to want to piss anyone off.... :hoist:

Ron, I was told it'll hold good and so far I believe. As hard as I pushed it the other day and good as it ran I can't complain. I have several parades around here and 1 show in Va that has a military theme to them and they want me to come so I will.