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I have a car with a burnt valve. I found a rebuilt head on Ebay, but the head has been sitting in the trunk of another car for years (15 I think). Can I buy this and just put it in?
I do not know what is involved in rebuilding a head other then usually new valves. What I know is I take it to the shop and say rebuild this head please. Are there parts that decay with age if not used? Rubber seals? There is a risk that it is not actually rebuilt, but I will take that risk if it is the only risk. I will save almost a thousand dollars if I do this.
Thanks
And the rest of you - shame on you. get your mind out of the gutter.
Location: East of Seattle since 1992, 615' Elevation, Zone 8b - originally from SF Bay Area
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Yes, there are parts that deteriorate, but worse, it can be cracked or warped and that may not be visible to the naked eye. You have no idea of the condition of the valves, valve guides, lifters, or springs. Why was it removed
from the original car? Probably not because it was perfect. I'd surely get it rebuilt. Besides replacing parts they will check for warpage and resurface it
for a tight seal to the head gasket.
I have a car with a burnt valve. I found a rebuilt head on Ebay, but the head has been sitting in the trunk of another car for years (15 I think). Can I buy this and just put it in?
I do not know what is involved in rebuilding a head other then usually new valves. What I know is I take it to the shop and say rebuild this head please. Are there parts that decay with age if not used? Rubber seals? There is a risk that it is not actually rebuilt, but I will take that risk if it is the only risk. I will save almost a thousand dollars if I do this.
Thanks
And the rest of you - shame on you. get your mind out of the gutter.
Lots of variables to consider. Not all heads are the same, and some engines were known for having specific kinds of problems with the heads. For instance, some SBC 350s were known for developing cracks in the heads between two specific cylinders. Others were not. Go figure...
If this were my vehicle, and I bought that head off eBay, I'd take it to a trusted machine shop & have them check it over. There could be cracks undetectable by the naked eye. It could also be warped.
I'd hate to see you go to all the work & expense of installing it, only to find that it's defective.
But if it's old head, then she'll need to pop her false teeth out first.
No drag that way.
Anyway, what is so unique or unusual about this engine that you can't find a good, low-mileage used version at the local boneyard? Or a reasonably priced reman unit from your local parts store?
I'd be sceptical about buying this one. I'd definitely want the backstory on why it was rebuilt and placed in a car trunk rather than installed on the engine it was rebuilt for. I've had my share of projects that I've started and sold unfinished so I wouldn't totally rule out the possibility that this is legitimately a good part, but I'd still want something to make me feel good about it before I took the plunge.
As far as what's involved in a head rebuild:
Dissasemble;
Clean the head itself;
Magnaflux head to check for cracks; check deck for straighness and/or pits, resurface if necessary;
Check tolerances on valve seats and guides, replace if necessary, otherwise recondition valve seats;
Check valve stems for straightness and faces for burns; replace if necessary, otherwise recondition the faces;
Check tension on springs, replace if necessary;
Check other parts for wear (keepers, rocker arms, etc, varies depending on style of head) and replace or recondition as needed;
Reassemble head using new valve stem seals.
That's it in a nutshell. If it's done properly you end up with a part that for all intents and purposes is every bit as good as a brand new one from the factory. If it's done wrong you could end up with something that's worse than it was before the rebuild.
Anyway, what is so unique or unusual about this engine that you can't find a good, low-mileage used version at the local boneyard? Or a reasonably priced reman unit from your local parts store?
I'd be sceptical about buying this one. I'd definitely want the backstory on why it was rebuilt and placed in a car trunk rather than installed on the engine it was rebuilt for. I've had my share of projects that I've started and sold unfinished so I wouldn't totally rule out the possibility that this is legitimately a good part, but I'd still want something to make me feel good about it before I took the plunge.
As far as what's involved in a head rebuild:
Dissasemble;
Clean the head itself;
Magnaflux head to check for cracks; check deck for straighness and/or pits, resurface if necessary;
Check tolerances on valve seats and guides, replace if necessary, otherwise recondition valve seats;
Check valve stems for straightness and faces for burns; replace if necessary, otherwise recondition the faces;
Check tension on springs, replace if necessary;
Check other parts for wear (keepers, rocker arms, etc, varies depending on style of head) and replace or recondition as needed;
Reassemble head using new valve stem seals.
That's it in a nutshell. If it's done properly you end up with a part that for all intents and purposes is every bit as good as a brand new one from the factory. If it's done wrong you could end up with something that's worse than it was before the rebuild.
The engine is a lotus 907. There are not a lot of them around. If there are five 907s in junkyards in the US I would be surprised.
The head was supposedly rebuild but they never got around to putting it in. It sounds like it is probably not worth the risk. I just wanted to try to save both money and time.
I suppose that I will just find a cheaper core and get it redone at a place I know can do it right. I wanted to use stainless steel valves (or sodium filled valves if I can find them) anyway. The valves burn out easily and it is a pain to replace becuase they have mechanical lifters that have to be individually shimmed. I cannto find anyone in Michigan who can/will do the work for me. I do not want to do it myself having done it twice before - it is an awful job and I just do nto have time for it. . I may have to send the car to a guy in Georgia to swap out the heads what a PIA.
I have a car with a burnt valve. I found a rebuilt head on Ebay, but the head has been sitting in the trunk of another car for years (15 I think). Can I buy this and just put it in?
I do not know what is involved in rebuilding a head other then usually new valves. What I know is I take it to the shop and say rebuild this head please. Are there parts that decay with age if not used? Rubber seals? There is a risk that it is not actually rebuilt, but I will take that risk if it is the only risk. I will save almost a thousand dollars if I do this.
Thanks
And the rest of you - shame on you. get your mind out of the gutter.
Can this be done without extra work............NO!
I'm not going to tell you that gonzo repairs like this won't ever work it's just that there is 99.9% odds that it won't work correctyl
When it comes to parts like this I would never use anything but a professional fresh rebuild that included the proper machining. Anything else is just asking for issues and is a major dice roll.
The engine is a lotus 907. There are not a lot of them around. If there are five 907s in junkyards in the US I would be surprised.
The head was supposedly rebuild but they never got around to putting it in. It sounds like it is probably not worth the risk. I just wanted to try to save both money and time.
I suppose that I will just find a cheaper core and get it redone at a place I know can do it right. I wanted to use stainless steel valves (or sodium filled valves if I can find them) anyway. The valves burn out easily and it is a pain to replace becuase they have mechanical lifters that have to be individually shimmed. I cannto find anyone in Michigan who can/will do the work for me. I do not want to do it myself having done it twice before - it is an awful job and I just do nto have time for it. . I may have to send the car to a guy in Georgia to swap out the heads what a PIA.
I'm finding it hard to believe that nobody in Michigan can/will work on this head, given all the speed shops and competent independent automotive machine shops there.
This head is no more difficult to work on than a Jag or an Alfa-Romeo, to name but two DOHC alloy head design motors that have been around since the 1950's and use solid shims to adjust the valve clearances. With all the latest motors using alloy heads and 4-valve designs ... such as the DOHC Subaru's of the late 1990's ... this type of technology is neither rare, difficult to work on, or so unusual that nobody has the knowledge, experience, or tooling to work on them.
Your biggest concerns on this head will be that it is straight, within specs for flatness, and is crack free. A magnaflux inspection and pressure testing will confirm that it's OK or not; any competent automotive machine shop can do this work.
I wouldn't use stainless steel valves in this application but would try to find stellite faced valves as these are more durable and the 907 series motor was well known for having less than sturdy valves in it. Sodium filled ex valves would be nice, but an unlikely find.
While there may not be a lot of parted out cars/motors of this series in the USA, an available head that was "rebuilt" some years ago should be a good starting point for a serviceable head now. After 15 years, if it wasn't securely packed into a plastic wrap with some light preservative oil on it ... it may have rust issues at the valve faces/valve seats, or other steel items in the head. But it wouldn't take much to tear it down, inspect it for these issues, and to determine if it can be restored to proper functioning.
I know of at least 6 machine shops in my local area that I would trust to do this work for a reasonable cost and it can't be that difficult to box up and ship a head UPS or FEDEX to them. Alternatively, it wouldn't be that difficult to remove the engine from the car and ship it out to a shop for the top end work if you're not inclined to do the top end yourself.
For starters, besides the actual condition unknown, how was it sitting in the trunk. Was it flat, on a side, cocked. Trunks are never perfectly flat. Then check the deck for straightness, and if its not, you can always get it decked. Then someone else mentioned the rest, some you can visually inspect, like the valves, what color are they, and some parts may be worth it to replace while the head is out.
I trust you are keeping this rig. I know many folks who thought they could fix and sell a Lotus for big bucks. Last auction I went to, one went for under $200. Nickel and Dime expenses of restoring one goes negative real fast.
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