1.94 Valve in Chevy 305 Heads (416 castings)

[F-BIRD'88]

If you have to machine and install new seats in the head its getting way beyond "budget".
Find a better casting.. I have never had problems with the combustion chamber wall on a 4416 head after deshrouding for 1.94/1.60 valves.. You need not get carried away in the chamber on these , unlike the more tightly shrouded chamber #601 casting.

Some people even put 2.02" valves in these heads.
I stick to 1.94/1.60 or 1.50 valves on this stuff.

[68maliblue]

Only one seat is this bad. The rest look useable as-is. I'll see what my machine shop says.

[BILL-C]

Took apart the other cylinder head and found this ugly exhaust seat. All the other seats look serviceable. This seat is recessed .060” and it looks like they just hit it with a 45 deg cut all the way out to the intake. Is this head scrap or can a replacement exhaust seat be installed without hitting water?

That head had the wrong seat installed. very poor workmanship. Yes, you can get it to run ok, but considering how much work you are going to have into this project you will thank yourself later if you get another casting. Have you ever seen a 305 vortec head?

[68maliblue]

Yes I have but they are pretty pricey around here. Around $200 - $250 used. Used 906 or 062 vortecs are half that. By the time i get done refurbishing them might as well buy new aftermarket heads for a couple hundred more.

[Racer97]

I have a 450 casting if you want it it's about the same as 416 just 1.72 intake and the chamber is a few cc bigger but can be matched with some grinding. Just pay shipping

[68maliblue]

Thanks for the offer Racer97. I'm going to take a step back and think about my options on this one and regroup for now.

[F-BIRD'88]

If you put your feelers out, you should be able to find another set of 4416 heads for under $100, locally
Often on whole running 305 engines. Many just want to give them away to anyone who will pick up, locally.

[PRH]

For a low buck “ Rube Goldberg” type repair....... that seat could be cut out and a slightly taller one could replace it, which would probably get you back most of the .060” sunk that you have now.

It probably wouldn’t even be worth considering it, but......it looks like they’re already cleaned, blasted, etc...... and you already own it.

The seat could be replaced in that head in less time than it would take to strip and clean another head.

If you walked into my shop with it....... I wouldn’t have a problem swapping out the seat.

[68maliblue]

Thanks PRH for the advise. I did strip the heads and have them hot tanked and magged so I'm out $50. They were so dirty I didn't see this, much less pay much attention until they were cleaned. The rest of the seats look ok so it shouldn't be too much expense to replace 1 seat properly.

[In-Tech]

For a low buck “ Rube Goldberg” type repair....... that seat could be cut out and a slightly taller one could replace it, which would probably get you back most of the .060” sunk that you have now.

It probably wouldn’t even be worth considering it, but......it looks like they’re already cleaned, blasted, etc...... and you already own it.

The seat could be replaced in that head in less time than it would take to strip and clean another head.

If you walked into my shop with it....... I wouldn’t have a problem swapping out the seat.

^^^^^This... most machine shops will put a seat in pretty cheap if you are already paying for a valve job/surface

[Bob Hollinshead]

you could look for a 434 casting head, they were on the 267 or 262 engine of the mid/late 70's. It's an odd ball head-for some reason when GM casted this head they made it way thicker than the 305 castings. They aren't scalloped around the outer head bolt areas and will take a 1.94 valve easy with unshrouding, They end up with around 64cc chamber when done. The ports are also thick enough to be ported to the 170cc range easily.

[Carnut1]

you could look for a 434 casting head, they were on the 267 or 262 engine of the mid/late 70's. It's an odd ball head-for some reason when GM casted this head they made it way thicker than the 305 castings. They aren't scalloped around the outer head bolt areas and will take a 1.94 valve easy with unshrouding, They end up with around 64cc chamber when done. The ports are also thick enough to be ported to the 170cc range easily.

For an experimental 331 I once did a set of 434 heavy cast set to 2.055/1.6 valves. I did go through one of the bowls and welded it up. The second time I went to update the porting I ruined them. It was a street runner and had issues with traction but ran very well for what it was. Thanks, Charlie

[Bob Hollinshead]

you could look for a 434 casting head, they were on the 267 or 262 engine of the mid/late 70's. It's an odd ball head-for some reason when GM casted this head they made it way thicker than the 305 castings. They aren't scalloped around the outer head bolt areas and will take a 1.94 valve easy with unshrouding, They end up with around 64cc chamber when done. The ports are also thick enough to be ported to the 170cc range easily.

For an experimental 331 I once did a set of 434 heavy cast set to 2.055/1.6 valves. I did go through one of the bowls and welded it up. The second time I went to update the porting I ruined them. It was a street runner and had issues with traction but ran very well for what it was. Thanks, Charlie

Charlie, did the 434 casting appear thicker than the typical 305 castings in your opinion? I don't know what molds they used to cast these with but they carried over the exterior design of the pre-lightweight heads for sure. I carved on a set years ago and there was all the metal there that I needed-engine ran good and is still going.

[1980RS]

you could look for a 434 casting head, they were on the 267 or 262 engine of the mid/late 70's. It's an odd ball head-for some reason when GM casted this head they made it way thicker than the 305 castings. They aren't scalloped around the outer head bolt areas and will take a 1.94 valve easy with unshrouding, They end up with around 64cc chamber when done. The ports are also thick enough to be ported to the 170cc range easily.

For an experimental 331 I once did a set of 434 heavy cast set to 2.055/1.6 valves. I did go through one of the bowls and welded it up. The second time I went to update the porting I ruined them. It was a street runner and had issues with traction but ran very well for what it was. Thanks, Charlie

My buddy had a 267 that he blew up in his Monza, he did what you have suggested as his brother owned a machine shop at the time. Dropped those heads on his 350 with a new cam, it was quite impressive for what it was.

[jeff swisher]

I have ran the 1.72" valved 450 head on a 357" with 280H comp flat tappet.
6700RPM shift points TH 350 4.57 gear 3300lb 78 Nova.
Those small valve heads were only bowl ported and stock tiny valves left in them, the car went 12.51 @ 111 MPH.
Converter stalled to 2200 RPM.

601 casting 305 heads are my favorite and were pretty easy to find around here a decade ago.
1.84-1.50 valves stock and chambers I measured came in at 53.5cc.
I leave the stock small valves in them.
Not hard to make a 12 second 350" with them.

Like others said you do not need to take much from the sides of the chamber.
The power in the chamber is near the spark plug on the intake side.