Found a set of 305 heads that I could use on my 307. They are used, but have some bowl blending and port work done. What should I be looking for when I look at them to be reasonably sure that they are usable? How do you check if the guides are good? Are there any "don't buy" telltales?
Chevello
Just remember that unless they are bagged and tagged with a recent reciept from a machine shop, you are buying cores. The only way to know if they are any good is get them to a machine shop to check for cracks, straightness, and everything else that need be on good shape to bolt them on.
some 305 heads had small 1.72" intake valves and a bigger chamber than i find on the 601 head.
I like the 601 and the 416 head seems to have followers.
now a straight edge laid on top of the valves will tell you if all depths are the same.. if they are really close i have discovered this is a small indicator that the guides are good....
Clean the chambers with a wire brush and look for cracks or small rusty lines..indicating a crack...
Look into the ex and intake runners..look for light coming through the valve seat area..if it has valves in it.
look for any stripped bolt holes ...but a guarantee from the seller..and a trip to the machine shop for a magnaflux is best.....
I usually pay 50 for a pair of core heads with even depth valves...I have paid more but try not to
I usually buy 2 different sets of valve springs so i can eliminate the rotators and do not need to shim the valves to get my seat pressure i need..
Buy retainers or grind stock ones down to get the lift clearance issues resolved.. I run viton valve guide seals and and clearance before bind usually is .450"-.460" if stock non tweaked retainers are used.
Enjoy!
I like the 601 and the 416 head seems to have followers.
now a straight edge laid on top of the valves will tell you if all depths are the same.. if they are really close i have discovered this is a small indicator that the guides are good....
Clean the chambers with a wire brush and look for cracks or small rusty lines..indicating a crack...
Look into the ex and intake runners..look for light coming through the valve seat area..if it has valves in it.
look for any stripped bolt holes ...but a guarantee from the seller..and a trip to the machine shop for a magnaflux is best.....
I usually pay 50 for a pair of core heads with even depth valves...I have paid more but try not to
I usually buy 2 different sets of valve springs so i can eliminate the rotators and do not need to shim the valves to get my seat pressure i need..
Buy retainers or grind stock ones down to get the lift clearance issues resolved.. I run viton valve guide seals and and clearance before bind usually is .450"-.460" if stock non tweaked retainers are used.
Enjoy!
Great info so far. The guy is supposed to get me the casting numbers this evening so I'll find out if they are the 601 or 416 then. He wants 75 for them, so it sounds a little steep for cores unless they were recently redone. If they are 416 then I'm hoping they are bolt on usable. If not there is a disassembled set of known 416s that are on cl for 50 already disassembled and clean. I'm more worried that those would be something the machine shop rejected as junk.
Either way, I'm learning :thumbsup:
Either way, I'm learning :thumbsup:
I have got 1 cracked 601 head out of 22 heads.
I have had many 1987-1995 heads with cracks.. most cracks are in the ex port or ex seat...
the 601 i had was cracked in the ex seat.. i ground the seat and when i went to lap the valve i noticed a small section that would not lap....in the seat area??
So i lapped some more...still the same....I figured it was toast and so i lapped it with a drill and coarse compound...I seen a tiny tiny crack in the seat..this valve is now sunk....Funny thing is that i had the pair magnafluxed before i began.
I think it was a little hot at one time as there was a place on the deck that was a low spot that took a bunch of surfacing to remove....right near the cracked area..well 3" from it.
I had many hours of porting in this head...
crap happens!
I have had many 1987-1995 heads with cracks.. most cracks are in the ex port or ex seat...
the 601 i had was cracked in the ex seat.. i ground the seat and when i went to lap the valve i noticed a small section that would not lap....in the seat area??
So i lapped some more...still the same....I figured it was toast and so i lapped it with a drill and coarse compound...I seen a tiny tiny crack in the seat..this valve is now sunk....Funny thing is that i had the pair magnafluxed before i began.
I think it was a little hot at one time as there was a place on the deck that was a low spot that took a bunch of surfacing to remove....right near the cracked area..well 3" from it.
I had many hours of porting in this head...
crap happens!
He got back to me and said they are 601 castings. Mortec says they are 53cc combustion chambers. From what I have been reading that would put me at 11:1. I'm preeeeety sure that tired old bottom end would not be happy with that. Is there any easy way to get this CR down to something pump-gas-able? Thicker head gaskets? That just sounds scary on its own.
This is not the final engine for the car, but I'm hoping for some simple upgrades that will make it a bit more fun than the 2bbl and low low compression it already has. I'll be adding 4 bbl and intake as well as one of the cam recommendations I hope to get from another thread that will start at that time
The HAMB thread about the 307 recommends a few different cams as well.
That's where I am. Trying to figure out if I want that high of a CR. I'm also assuming that the bottom end is OK. The odometer reads 00946, so it's either 100946, 200946 or 300946 miles
This is not the final engine for the car, but I'm hoping for some simple upgrades that will make it a bit more fun than the 2bbl and low low compression it already has. I'll be adding 4 bbl and intake as well as one of the cam recommendations I hope to get from another thread that will start at that time
The HAMB thread about the 307 recommends a few different cams as well.That's where I am. Trying to figure out if I want that high of a CR. I'm also assuming that the bottom end is OK. The odometer reads 00946, so it's either 100946, 200946 or 300946 miles
No way to get 11:1 with a 53.5cc head..as that is what mine checked at and after some chamber unshrouding and blending for more power i get 57cc-58cc
If you run a gasket at .015" and gasket bore at 3.875 and the piston is in the hole .020" stock bore and 6cc valve releifs... with that 53.5cc chamber you get
10.48 compression...
I bet the piston is down the hole further and the gasket bore is closer to 4+"
I run 10.4 in my 350 with the 601 and .038" gasket piston down the hols .013"
I also have the comp 268H ground on a 106LS
Do some measuring and see what you really get.
I have taken the 601 chamber to 62cc with 1.94" and 1.50" valves...
still small and very efficient.
There are pics of the chamber mods in the 416 head thread
I guess if you have domed pistons you could get 11:1
If you run a gasket at .015" and gasket bore at 3.875 and the piston is in the hole .020" stock bore and 6cc valve releifs... with that 53.5cc chamber you get
10.48 compression...
I bet the piston is down the hole further and the gasket bore is closer to 4+"
I run 10.4 in my 350 with the 601 and .038" gasket piston down the hols .013"
I also have the comp 268H ground on a 106LS
Do some measuring and see what you really get.
I have taken the 601 chamber to 62cc with 1.94" and 1.50" valves...
still small and very efficient.
There are pics of the chamber mods in the 416 head thread
I guess if you have domed pistons you could get 11:1
Thanks for your help, Andy and Jeff. I thought I responded to this last night, but I must have missed the button. Last night he got back to me with the info that these have new springs and retainers.
Is 10.48:1 too much for pump gas and a tired bottom end? I'm not sure I'm brave enough to break out the grinder for the chamber.
Where do I measure the valves to be sure they are the 1.84" intakes? Will it matter very much if they are the 1.72"?
I guess I'll take a look at them tonight and if there are no obvious warning signs, pick them up. I can use them on a 350 as well, so they won't be a total loss if they don't work out I think.
Is 10.48:1 too much for pump gas and a tired bottom end? I'm not sure I'm brave enough to break out the grinder for the chamber.
Where do I measure the valves to be sure they are the 1.84" intakes? Will it matter very much if they are the 1.72"?
I guess I'll take a look at them tonight and if there are no obvious warning signs, pick them up. I can use them on a 350 as well, so they won't be a total loss if they don't work out I think.
So I tell the guy that I'll come down (35 miles from NE Phila to SWP) and where would he like to meet. His response: "They're still on the engine, so you'll have to come by the house." When you guys have a set of heads that you are selling, do you have them on the engine still?
Maybe this is a good thing. What do you guys think?
Maybe this is a good thing. What do you guys think?
well if the thing runs let him fire it up or if it just cranks over do a compression check..
But sounds like a pain if you have to pull them..
no biggie unless the engine is in the vehicle..
You will have higher compression with them in a 350.
You should actually check deck clearance on what you have now..
And check to see if you have a real flattop piston..
I would bet with a .038 gasket the compression will be in the low to mid 9's with stock non touched 307.
I have stuck those 305 heads on engines with 200,000 miles and never had an issue....
If your lower end is worn out does it really make sense to try to make more power?
Worn out or tired is way different than many many miles..if she is maintained correctly even 200,000 miles is just barely broke in.
But sounds like a pain if you have to pull them..
no biggie unless the engine is in the vehicle..
You will have higher compression with them in a 350.
You should actually check deck clearance on what you have now..
And check to see if you have a real flattop piston..
I would bet with a .038 gasket the compression will be in the low to mid 9's with stock non touched 307.
I have stuck those 305 heads on engines with 200,000 miles and never had an issue....
If your lower end is worn out does it really make sense to try to make more power?
Worn out or tired is way different than many many miles..if she is maintained correctly even 200,000 miles is just barely broke in.
I'll try again this weekend to go pick them up. It would have been nice if I could just stop off and grab them. I didn't want to make a production out of it.
I'm a little concerned about the bottom end just because it is such an unknown. I haven't even cranked the thing over yet. It'll probably be fine since these don't really make enough power stock to hurt themselves.
I'm a little concerned about the bottom end just because it is such an unknown. I haven't even cranked the thing over yet. It'll probably be fine since these don't really make enough power stock to hurt themselves.
It would be a great opportunity to see them working, or at least get a compression test done like said before.
The only issue is have with them being installed is that you cannot inspect the sealing surfaces till they are off, and the fact that you have to wait till they are unbolted, or pick up a wrench yourself and give a hand.
The only issue is have with them being installed is that you cannot inspect the sealing surfaces till they are off, and the fact that you have to wait till they are unbolted, or pick up a wrench yourself and give a hand.
I passed on them. I decided I'm not interested in Pick-A-Part from the guy. Probably would have had to bring my own tools, and I didn't feel like driving an hour to hang out with him. He also told me to call him when I got down there so he could give me the address, but didn't respond when I asked for his number.
I'm not at the point where I'm going to need them soon anyways, so no great loss.
Thanks for the info guys. I'm sure I will use it eventually
I'm not at the point where I'm going to need them soon anyways, so no great loss.
Thanks for the info guys. I'm sure I will use it eventually
The old fashioned way? You mean the GPS that doesn't have a phone in it?
Growing up in Los Angeles, there was always a LA and OC Thomas Guide in the car. When I moved to Philadelphia I was astonished that nobody had heard of that. Then I started getting directions from people: "Yeah, go down hear past the bridge to where the old Hess station was at, and turn right onto that road right there. Go about three blocks and hang a right towards the river and then turn right at the cemetery. It's the house with the white awnings just past Eddie's bar." Street signs are about a 50/50 chance either missing or hidden in a tree.
Growing up in Los Angeles, there was always a LA and OC Thomas Guide in the car. When I moved to Philadelphia I was astonished that nobody had heard of that. Then I started getting directions from people: "Yeah, go down hear past the bridge to where the old Hess station was at, and turn right onto that road right there. Go about three blocks and hang a right towards the river and then turn right at the cemetery. It's the house with the white awnings just past Eddie's bar." Street signs are about a 50/50 chance either missing or hidden in a tree.
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