Advice on heads installation |
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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Posted: May-31-2022 at 10:08am |
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Thanks Tom. I appreciate that. I too am from the pre-internet era (3 TV channels,5 w/Reynolds wrap.)
Doing that at 16 is darn impressive. Taking thurs and fri off for a four-day marathon. I appreciate the attention to this. |
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mosinee77
Newbie Joined: March-28-2022 Location: Central WI Status: Offline Points: 39 |
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No you are not... good solid advice here....I re-built my first small block when I was 16, back before the interweb and the access to unlimited information, I used an old "Motors Services" manual in an old shed... the engine ran just fine and was abused severely by 16 year old me and the 4 speed behind it... been doing engine work for the (44) years since Swapping heads is more about looking for odd wear patterns on the parts (if used), and making sure the lash is done correctly and within spec. Hydraulic lifters are more forgiving on the subject of lash, but it still needs to be within spec. Good Luck.... Tom
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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Thanks. Going step by step!
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MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3750 |
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Best practice of course is to always keep the parts on the exact locations they come off of and if you can't to use new parts but many thousands of engines were repaired without the owner knowing this rule of thumb and I don't recall anyone coming back and telling us their rocker arms or push rods failed due to this. Even new parts will need to break in on start up. Follow a simple break in procedure and use a good assembly lube on the parts to help them break in and you will be fine.
Around 2002 I rebuilt an engine for my son's truck, we bought all our parts but at that time there was a nationwide lifter shortage, the only lifters available at that time were Moresa lifters out of Mexico, shops I know told me not to run Moresa back then because they were seeing 15-20% failures with them. ( maybe Moresa lifters are a quality part today, I have no idea but in 2002 they were trouble ) I installed the brand new camshaft in that freshly rebuilt engine with all 16 of the old factory stock lifters that had 120,000 miles on them, I took them apart and cleaned them well before install then I broke the cam in carefully on those used lifters and that engine ran great many years till we sold the truck. The lifter is much more critical and prone to failure than the push rod and rocker arm. It was the wrong thing to do I know that, but had no choice at that time. Parts can be re used if they are in good condition. Machine Shops do it all the time, but I have never seen a machine shop re use any lifters so don't follow my lead on that one.
Sealed Power still sells a nice assembly lube, part # LL5 comes in a 4 oz bottle and one bottle will take care of an engine assembly with lots to spare. It is a very high quality assembly lube and works well. |
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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Thanks. That is a huge help.
I don't have the old heads so i don't really know, but it's ok. New rods aren't expensive and it just makes me feels better anyway... kinda the same way you'd swear you car runs better after it's washed. Your remark on the wearing pattern makes sense and is also a relief. This is a budget restoration for the here and now... Plenty of winters to pull and re-do from the block up if it comes to that. I will meditate on the distributor...stay tuned. Many thanks to you both. |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11112 |
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As far as your distributor question way back in the beginning, you'll be better off rotating the engine so that you're torqueing the rocker bolts on a cylinder with both valves shut and then after everything is done and the intake is back on, put the engine at TDC on the compression stroke for #1 cylinder and installing the distributor.
You can find directions here on CCF or just ask if you're having trouble.
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11112 |
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Here's a link to some 85 stock replacement pushrods at RockAuto
They're 8 182 inches not the 8.185 that I said numerous times. PS i don't think you've verified what your 78 had for rockers yet, the stamped steel or the cast iron. If they're stamped steel, you could reuse the old pushrods.
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11112 |
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Since Ford's number for lifter preload is .020 to .060 inches, if you figure you had .040 (right in the middle of the range) and the new heads should have the longer pushrods to get you to the same general spot of .040 inches and you use the old pushrods instead, then you'd be outside of the range at .005 inches of preload.
In the above example if you had .030 instead of .040 inches and used the old pushrods, you'd have a gap of .005 inches between the pushrod and lifter and it'd be banging and clanging like an old singer sewing machine. Knowing the guy you got the heads from, he PM'd me that they were stock, no machining of any kind and low hours and good running when removed. I'd bolt them on and use some new 8.185 pushrods to give you a much better chance of being near the middle of the spec. Somebody might say that you're mixing and matching new parts and old, in this case new pushrods and old rocker arms and lifters. They should wear together with no problems. Most everybody here on CCF who's replaced their original heads on say an 80's 351w with gt40P's has reused their old correct length pushrods without giving it a second thought and their pushrods and rockers wore to match each other just fine. They might have needed shims that were mentioned earlier in the thread if the heads were milled down quite a bit at the machine shop, but yours have had no machining. If they used the original rockers, then the rockers and the valve stems would have to wear to match each other. Kind of a vicious cycle, something has to wear to match the old and new parts unless you're replacing everything. The earlier link to an old thread with the "Shep72 method" works good for showing that your preload falls in the recommended range. Keep in mind that there are more sophisticated methods of checking preload but this works good I've done the same swap on a 70's engine with 80's heads and pushrods with no problems and lots of running hours later it's still doing good. I hope that all this makes sense to you And thanks for the info from that unnamed character you got the heads from.
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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Warden Keno,
I'm assuming that .035 doesn't fall within that range of 'just enough" to land me in jail. Is that correct? |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11112 |
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Did it in my head and checked it with an abacus, a slide rule, an old Texas Instruments calculator, then checked it again on online calculator.com.
It kept coming out the same..................035 difference So what's your "old math" telling you?
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MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3750 |
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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Willco sir
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11112 |
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Those words should be saying "This won't be bad at all"
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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I'm without words....
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11112 |
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Not really Here's a link to an old thread with some good info So do you have the same style rocker arms on both the newer 85 heads and the older 78 heads? What do you have for pushrods? If needed, new stock pushrods to go with your 85 stamped rockers are cheap They're .035 inches longer than your 78 pushrods 8.185 inches vs 8.15 inches
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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Boy I'm in trouble....
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Gary S
Grand Poobah Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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Google lifter preload and also look for youtube video's. On Fords depending on what rocker arms and their mounting systems polylocks or different length pushrods for rail rocker arms or shims and different length pushrods on the newer style pedestal mounts. Using different length pushrods requires you measuring their length and having them made to your spec's. If you have the later rockers the easiest method are these shims- https://performanceparts.ford.com/part/M-6529-A302
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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I didn't think lash had to be set with hydraulic lifters. I've been imagining 19ft/lbs was the requirement. |
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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The 85s were taken off the other engine and I've only cleaned them up. I haven't done any measurements with respect to the pushrods. The bad heads are still at the machine shop where they're waiting for their $100.
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mosinee77
Newbie Joined: March-28-2022 Location: Central WI Status: Offline Points: 39 |
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KENO, I usually live my life being a "decade off".... |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11112 |
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You're about 1 decade off on the pedestal mount rockers ,,,,,,,,,,,,,1978 Since the engine in his 1978 boat may be a 1977 as they commonly weren't necessarily the same as the boat year, that why I asked him the same question about the rockers
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mosinee77
Newbie Joined: March-28-2022 Location: Central WI Status: Offline Points: 39 |
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You need to make sure of the rocker arms being the same and the pushrods need to be verified. Also, in the mid-late '80s Ford changed the mounting again to a pedestal mount for the rockers. This will look quite different on rocker mounting.
Bottom line, whatever heads you have, can be used, you just need to make sure to have the correct rockers and pushrod/length for the application. I would set the valve lash as outlined numerous YouTube vids and online, it is very easy to do correctly. If you have taken the lifters out, make sure they are wearing properly (not scored or mis-shapen) and make sure they go back into the same bore they came out of, same with pushrods if you are re-using. Good Luck! |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11112 |
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Do your old 78 heads have the same rocker arms as the 85 heads?
The 85 will be stamped steel and the 78 might have cast iron rocker arms. They used slightly different pushrod lengths (just enough to maybe screw up your lifter preload pretty good) What's the history of the 85 heads, rebuilt or just taken off of another engine?
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NeilMcG
Senior Member Joined: September-20-2021 Location: Pittsburgh, PA Status: Offline Points: 228 |
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78 SN. Had to replace both heads (cracked.) Got a pair of '85 heads and have them cleaned and ready to go.
Engine hasn't been rotated since disassembly and the rotor's position was marked prior to pulling the dist. What do I need to consider when replacing the heads? My thought was that tightening the rockers would return the valves to their proper position by the push rods/cam lobes. Is there a need to rotate to TDC? Can I just tighten up, put the dist in with the rotor to the mark and go? |
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