Need help with 351W heads
#1
Need help with 351W heads
So I've fallen victim to the old "it's just a few more bolts" tale and have now dove all the way down to replacing the heads on my truck. She's an 86 250 with the 351W HO and I've already done headers, now I was just going to do the intake and slap an Edelbrock 2181 on it but I got down that far and then decided to do valve covers and then decided to take the trashy smog heads off and let her breathe. My neighbor was kind enough to give me a couple sets of heads and I'm going to use the D0OE set that he gave me but i have no idea what has been done to them. Here's some images i grabbed before I came in for dinner, hopefully y'all can share some wisdom.
Anyone have any clue what brand these rockers are?
As you can see this head had a rocker and stud stolen from it as my neighbor had a broken stud in his race truck and took this one out so they no longer match. Is this an issue?? This kind of stuff is beyond my knowledge and my father is no longer with us so i cant ask him anymore.
Thank you all in advance, let me know if y'all need any more pictures or info I'll answer all the questions i can!
Anyone have any clue what brand these rockers are?
As you can see this head had a rocker and stud stolen from it as my neighbor had a broken stud in his race truck and took this one out so they no longer match. Is this an issue?? This kind of stuff is beyond my knowledge and my father is no longer with us so i cant ask him anymore.
Thank you all in advance, let me know if y'all need any more pictures or info I'll answer all the questions i can!
#2
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What size valves and combustion chambers do those heads have? The good D0OE heads have 1.84/1.54" valves and 60cc chambers, if that pair doesn't at least have that they aren't worth putting any money into.. and you will have to put some money into them to use them. They need a trip to a machine shop for a detailed inspection, you want to know if the valve guilds are warn and have harnened valve seats installed, and that there are no cracks. The problem is it's easy to spend the same money to reburbish heads like this that you could get a pair of used performance heads for.. like early Edelbrock Performers for example, and even the lowly Performer is a better overall head than these would be with all new parts and a port job.
#3
What size valves and combustion chambers do those heads have? The good D0OE heads have 1.84/1.54" valves and 60cc chambers, if that pair doesn't at least have that they aren't worth putting any money into.. and you will have to put some money into them to use them. They need a trip to a machine shop for a detailed inspection, you want to know if the valve guilds are warn and have harnened valve seats installed, and that there are no cracks. The problem is it's easy to spend the same money to reburbish heads like this that you could get a pair of used performance heads for.. like early Edelbrock Performers for example, and even the lowly Performer is a better overall head than these would be with all new parts and a port job.
#4
With the machine shop prices in my neck of the woods, those heads are scrap.
I too would look into an aftermarket head. It's free to look. You could stand on the side of the road with a cardboard sign asking for money for aluminum heads. If you did, you would be the first person I would give a few dollars to.
I too would look into an aftermarket head. It's free to look. You could stand on the side of the road with a cardboard sign asking for money for aluminum heads. If you did, you would be the first person I would give a few dollars to.
#5
I think that you should tear the heads down and get a good look at them. A fresh valve job and they might be just fine. That looks like a piece of a ring sticking out from the intake valve on the one chamber so they were on an engine that was hammered in some way at least in that cylinder. Many times little pieces have a way of flying around through the whole engine and putting little dents in the valves and seats. Normally this is easily fixed with a grind.
Take a careful look at the valve spring package. Those are aftermarket 10 degree or Super 7 retainers and who knows what valve spring. They might work but they will need to be tested to make sure that the loads are appropriate for your application.
Take a careful look at the valve spring package. Those are aftermarket 10 degree or Super 7 retainers and who knows what valve spring. They might work but they will need to be tested to make sure that the loads are appropriate for your application.
#6
I think that you should tear the heads down and get a good look at them. A fresh valve job and they might be just fine. That looks like a piece of a ring sticking out from the intake valve on the one chamber so they were on an engine that was hammered in some way at least in that cylinder. Many times little pieces have a way of flying around through the whole engine and putting little dents in the valves and seats. Normally this is easily fixed with a grind.
Take a careful look at the valve spring package. Those are aftermarket 10 degree or Super 7 retainers and who knows what valve spring. They might work but they will need to be tested to make sure that the loads are appropriate for your application.
Take a careful look at the valve spring package. Those are aftermarket 10 degree or Super 7 retainers and who knows what valve spring. They might work but they will need to be tested to make sure that the loads are appropriate for your application.
#7
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Further to this... I believe these heads have pressed in rocker studs which have been known to pull out some with high rate springs. Back in the day the fix for this was to pull them and drill n tap the holes for screw in studs, but again that is more $$. For a stock or near stock rebuild these OEM studs are fine as high rate spring sets aren't needed for a relatively mild cam.
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#8
Further to this... I believe these heads have pressed in rocker studs which have been known to pull out some with high rate springs. Back in the day the fix for this was to pull them and drill n tap the holes for screw in studs, but again that is more $$. For a stock or near stock rebuild these OEM studs are fine as high rate spring sets aren't needed for a relatively mild cam.
#10
I'd inspect those heads very carefully and completely - The heads may have micro-cracks from where it ate the piston, and valves may be bent from debris in the cylinder as well. BTDT.
I had a pair of aftermarket iron heads that dropped an intake valve seat insert that got munched by the piston. Being that intake valve was essentially open at that point, the debris was sucked/blown around the four cylinders fed by that 'half' of the dual-plane intake, damaged those pistons and also a few valves that were held off their seats by debris when the piston came up - bending those as well. This carnage happened at start-up/idle! By the time I would have paid for a half dozen valves in both heads, a new (oversize) valve seat insert, and machining costs for the above, it was a no-brainer to simply buy another set of heads.
Unless those D0OE 351W iron heads were professionally ported, you'll probably be better off with just about any aftermarket aluminum heads. I was able to score a new pair of aluminum RHS 200s for less than a grand, shipped.
I had a pair of aftermarket iron heads that dropped an intake valve seat insert that got munched by the piston. Being that intake valve was essentially open at that point, the debris was sucked/blown around the four cylinders fed by that 'half' of the dual-plane intake, damaged those pistons and also a few valves that were held off their seats by debris when the piston came up - bending those as well. This carnage happened at start-up/idle! By the time I would have paid for a half dozen valves in both heads, a new (oversize) valve seat insert, and machining costs for the above, it was a no-brainer to simply buy another set of heads.
Unless those D0OE 351W iron heads were professionally ported, you'll probably be better off with just about any aftermarket aluminum heads. I was able to score a new pair of aluminum RHS 200s for less than a grand, shipped.
#12
#13
Sorry to take so long to get back to you all, got busy with work and the truck got put on the back burner. Took them to my machinist and he cleaned them up and inspected them, no cracks to be found and he straightened the slightly bent valve out and inspected it for damage which there appeared to be none. Throughout this process I found out that these heads had both been ported and had hardened seats installed so they were actually worth my time. I brought them back home and reground all the valves and seats then lapped them all and installed them. Fast forward a week or so and they are installed on the truck and seem to be quite happy there but now I'm chasing carburetor problems which is a whole new ballgame within itself as you all know. Thank you all for your time and insight, I'm now going to debate buying a new carb as Summit Racing is only a mere 50 minutes from my house.
#14
Interesting to hear that your machinist straightened a bent valve.
I did this on a DOHC Honda a couple years ago the second time the valves hit the pistons, two valves were just a little bent. I was kind of exasperated with spending lots of money on it, and bought the cheapest head gasket on ebay etc. for the thing.
After straightening the valves to within 0.005" runout or so I refaced them and reinstalled, and the engine has run great for many years now.
Many years ago it was normal to straighten then reface slightly bent valves.
I did this on a DOHC Honda a couple years ago the second time the valves hit the pistons, two valves were just a little bent. I was kind of exasperated with spending lots of money on it, and bought the cheapest head gasket on ebay etc. for the thing.
After straightening the valves to within 0.005" runout or so I refaced them and reinstalled, and the engine has run great for many years now.
Many years ago it was normal to straighten then reface slightly bent valves.
#15
Interesting to hear that your machinist straightened a bent valve.
I did this on a DOHC Honda a couple years ago the second time the valves hit the pistons, two valves were just a little bent. I was kind of exasperated with spending lots of money on it, and bought the cheapest head gasket on ebay etc. for the thing.
After straightening the valves to within 0.005" runout or so I refaced them and reinstalled, and the engine has run great for many years now.
Many years ago it was normal to straighten then reface slightly bent valves.
I did this on a DOHC Honda a couple years ago the second time the valves hit the pistons, two valves were just a little bent. I was kind of exasperated with spending lots of money on it, and bought the cheapest head gasket on ebay etc. for the thing.
After straightening the valves to within 0.005" runout or so I refaced them and reinstalled, and the engine has run great for many years now.
Many years ago it was normal to straighten then reface slightly bent valves.