Hey guys,
So I've been pulling stuff apart on this 1974 F.5, and it got far enough down that we decided to just pull the head and refresh it since it's only a couple dozen fasteners away. I've got several questions (in bold below), bear with me please. Pics when I get a chance to update the thread, not near the truck at the mo.
0. The valve stem seals. Looks like the original part number 90913-02017 is NLA, but overseas distributors show Musashi MV120 as a replacement, which directly cross-references to the original P/N. I ordered 12 of these, coming from overseas (looks like Ajusa is reboxing the Musashi product, but I can't seem to find it at any of the domestic suppliers I normally solicit). These look like umbrella seals. My question: should I go ahead and use these for the head job, or is it possible to fit positive valve stem seals for a slight upgrade? On the usual engines I work on (read: much newer in design), I use EOK Viton seals and they've never let me down. EDIT: the valve stems and guides the same diameter between F.5 and 2F engines, I just checked the P/N's (same). So what I'm really asking is, what would you guys use?
1. Looks like the OE lifters are still available (supersedes to 2F P/N 13751-61010), as are the pushrods (supersedes to 2F P/N 13781-61010). I read around here that the original lifters aren't hardened on the face and thus wear out after a while; what do you guys recommend? Should I check for abnormal wear and replace lifters and pushrods, and what's the word on original vs aftermarket lifters? Engine has a serious (and I mean serious) sludging problem, where I'm mechanically dislodging giant chunks and sucking them out with a shop vac. Oil pan and pump are to be replaced, and I saw a lot of wear on the cam lobes (pics soon) so wondering if we should just rebuild the engine.
Thanks as usual.
So I've been pulling stuff apart on this 1974 F.5, and it got far enough down that we decided to just pull the head and refresh it since it's only a couple dozen fasteners away. I've got several questions (in bold below), bear with me please. Pics when I get a chance to update the thread, not near the truck at the mo.
0. The valve stem seals. Looks like the original part number 90913-02017 is NLA, but overseas distributors show Musashi MV120 as a replacement, which directly cross-references to the original P/N. I ordered 12 of these, coming from overseas (looks like Ajusa is reboxing the Musashi product, but I can't seem to find it at any of the domestic suppliers I normally solicit). These look like umbrella seals. My question: should I go ahead and use these for the head job, or is it possible to fit positive valve stem seals for a slight upgrade? On the usual engines I work on (read: much newer in design), I use EOK Viton seals and they've never let me down. EDIT: the valve stems and guides the same diameter between F.5 and 2F engines, I just checked the P/N's (same). So what I'm really asking is, what would you guys use?
1. Looks like the OE lifters are still available (supersedes to 2F P/N 13751-61010), as are the pushrods (supersedes to 2F P/N 13781-61010). I read around here that the original lifters aren't hardened on the face and thus wear out after a while; what do you guys recommend? Should I check for abnormal wear and replace lifters and pushrods, and what's the word on original vs aftermarket lifters? Engine has a serious (and I mean serious) sludging problem, where I'm mechanically dislodging giant chunks and sucking them out with a shop vac. Oil pan and pump are to be replaced, and I saw a lot of wear on the cam lobes (pics soon) so wondering if we should just rebuild the engine.
Thanks as usual.
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