The Break Down of a '69 Pontiac OHC inline six

Discussion in 'The "Other" Bench' started by TheSilverBuick, Dec 20, 2010.

  1. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    I am waiting on an exhaust valve so I can put together one head. They seem to be hard to find! :Dou:BUT yesterday I got an email saying a set of valves will be sent to me soon, and I'm getting them for free no less :beer


    A partial reason for a delay in this project is I just bought a house (well closing on it today!) and it has a good sized garage plus a nice 62ftx64ft pole barn with a section enclosed with concrete floor, insulated walls and a wood stove. So I've been delaying putting together the engine with hopes of NOT doing it in my basement! And it looks like the wait was worth it! I have a bellhousing swap and maybe an exhaust system swap to do on the Skylark before Drag Week, but otherwise I should be moving full speed on this once I move into the new place!

    This is how it sits in my basement right now.

    There is one bad valve, and the valves between the two heads I have are not interchangeable. Different lengths and different seat angles. One head has a bad valve and the other has a broken valve spring. And the parts weren't swappable =P
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    Ready to go back into the engine.
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    Avoiding assembling a long block in my basement =P
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    The new place.
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    In the pole barn.
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    Thanks for asking!
     
  2. sean Buick 76

    sean Buick 76 Buick Nut

    Very cool! Congrats on the wonderful new place!!! Leanne and I are moving into a new house in a month, sure will be great to have a warm home for my Turbo Skylark!
     
  3. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Thanks! I look forward to working on everything at ground level :pp

    I just got confirmation today that the guy that does porting on an Engine Masters Engine (first gen Hemi, with a MegaSquirt 3), is interested in doing port and chamber work on one of my cylinder heads. He asked for some pictures to familiarize himself with it before he gets the head. He has to make sure he is done with this years entry and has viper heads inline, but afterwards can fit mine in there. I need to get on getting a cam ground to custom spec's so I know what valves (lengths) and valve lift to go with to optimize the porting. Of course it's going to be turbo'd, so more is likely going to be better.
     
  4. sean Buick 76

    sean Buick 76 Buick Nut

    Sounds good! Just watch the overlap with the cam as you do not want reversion... I am sure you knwo that already though. :TU:
     
  5. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Things are starting to be on level ground. It's tough pulling stuff out of the basement!
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    Thinking of calling my barn the "Bird House" Thunderbird, Firebird, and the Skylark.
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    Inside the plywood area is insulated and has a wood stove.
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    And to not be completely off subject. I think I may of come up with a way to run sequential fuel injection right off the bat, before I get a crank trigger, on the OHC engine. I think I may be able to use the fuel pump eccentric as a cam sensor. Use a block off plate, tap a threaded hole into it, run a hall sensor to the high point of the eccentric then back off a hair. Then the points contacts will be the main Tach signal and the eccentric a cam sensor. I "think" this will work. I'm awaiting feed back from some other folks.

    The fuel pump is right next to the distributor.
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    And the shiny streak to the left of the gear is the fuel pump eccentric.
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  6. sean Buick 76

    sean Buick 76 Buick Nut

    Congrats on the new place! LOTS of room!!!:TU:
     
  7. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    It's a sickness I tell you (and heavy moving from a basement!)

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  8. sean Buick 76

    sean Buick 76 Buick Nut

    LOL, it is a sickness! There is no cure so enjoy the ride! I bought an acreage with a barn before I even bought myself a house LOL! But the Buicks and engines were safe and dry!:grin:
     
  9. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    UPDATE! The project looks like its going to start moving again!

    Got a box full of valves today! For the head that needed an exhaust valve I now have a full set of exhaust valves for it, but the intake valves I got have the wrong seat angle. One set of the intake valves might work in my other head, but that head set up needs a valve spring replaced. Since I'm just throwing this engine together I'm just going to replace the one exhaust valve.


    Genuine GM.
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    Good, Bad, Good. The retainer height is wrong and the cam follower was rubbing the retainer, which could unload the retainers and drop a valve.
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    So since I can now move forward with the project I decided to clean the remaining valves. Remember the head has been hot tanked and checked for cracks already.


    My valve cleaning machine.
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    After some green scotchbright.
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    I'm on schedule to yank the 400 out of the Firebird this weekend. I now have all I need to assemble one engine. I think I'll assemble one engine, make the oil system modifications to bump the main pressure up to ~60psi and run an external oil line to the lash adjuster galley. I think I'll build an engine test stand to fire the engine up on while I get the engine bay prepped with the right frame mounts and some wiring harness updates. Plus I need to build another MS3 and wire the car up (and come up with the intake and EFI arraignment). I'm getting two sets of water jetted manifold flanges to weld up an intake and exhaust (or two sets of...)

    ---------- Post added at 09:29 PM ---------- Previous post was at 08:51 PM ----------

    Oh, and I've already commissioned a head to be ported and the chamber reworked and opened up around the intake valve. Should get done next month.

    The guy doing the work did this head.


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  10. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Started putting the 250 I got back together. I had both the 230 and 250 block's cylinder walls sonic checked for thickness and the 230 had around a tenth of an inch thicker cylinder walls (same bore diameter as the 250), so I'll use that block for the 'good' engine, and the 250 will be my 'throw together' engine with on hand parts and a gasket kit.


    I picked up a reproduction '69 Pontiac service manual. I hear the '67 manuals are best for the OHC stuff, but I will manage with the '69.
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    Got my work area laid out.
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    Measured all the main bearing clearances. Using the used bearings that came out of the engine, they all averaged a hair over .003x". The metal temperature was in the 40* range, so they might tighten up a bit at normal room temperature, which will still put it on the upper range of OE spec's. This was the tightest one.
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    Got the crankshaft all bolted down. I did the usual 'forget' to install the rear main seals until it's all torqued down. D'oh! But have it all in now.
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    ---------- Post added at 07:23 PM ---------- Previous post was at 07:22 PM ----------

    To show the awesomeness of the wood stove. When I went into the barn.
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    A nice fire. Instantly making it nice right next to it, especially with the fan distributing the exhaust heat.
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    And after a bit, just three logs of wood. Nearly 80*F.
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    I cleaned the carbon off the pistons.
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    Installed the pistons. Gives new meaning to a slant six :)
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    Didn't think about the fact these rod bolts would be smaller than my Buick's. My usual rubber hoses didn't fit :ha: Had to make new ones.
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    I checked all the rod bearing clearances. They were a bit tighter than the mains. Average was under .003". This was the worse one.
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    The bottom end all bolted together.
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    ---------- Post added at 07:24 PM ---------- Previous post was at 07:23 PM ----------

    Then on to the head. The valves and seats are in pretty rough shape. Realistically it should get some professional work, but I'm not going that route with this one.
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    Time to lap the valves!
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    Essentially what most the valves looked like before and after.
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    Essentially what most the valve seats looked like before and after.
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    ---------- Post added at 07:26 PM ---------- Previous post was at 07:24 PM ----------

    Now for something more exotic, the oil system modifications to the head. I've seen the right rear head bolt boss drilled through and tapped to provide external regulated oil pressure to the lash adjuster galley. I was looking at that today and did not like the location. I would have to cut off a mounting boss, and could possibly have oil seeping from the head bolt when pressured up (even though it's only 12psi). I instead opted for a middle head bolt that falls under the valve cover so that if it does seep it's not an issue and it places the regulator between the oil fill pipe and the accessory drive from which it'll get it's oil feed.


    So I drilled through right here. I used a 5/16 bit for the actual hole to match that of the oil feed from the regulator, then I opened up the outside hole to 3/8ths to tap it with 1/8 NPT threading.
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    From the side.
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    I trimmed down the barbed fitting so it will not interfere with the head bolt.
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    This is with everything mocked up. I am thinking I will forgo the mounting bracket and get a straight pipe from the block to the regulator that will support the regulator. That would move the regulator away from the distributor. The feed will come from the oil pressure sensor location and I'll add a split so I can still get an oil pressure reading right off the pump. The lash adjuster will be regulated down to 12psi.
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    The next step is to block off the lash adjuster oil galley from the main line pressure. I think I'm going to try and get a straight tube, then drill out the opening where the restrictor/orifice tube went so the straight tube will fit snuggly. The orifice tube and passage from what I gather is slightly tapered, so a run through with a drill bit and a bit of sealant should be good.
     
  11. OHC JOE

    OHC JOE Mullet Mafia since 2020

    Hey bud looking good....have you ever talked to jerry woodland out in Utah or Richard mcdough in pharump nevada
     
  12. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Thanks. I've talked to Jerry on the phone a couple times and have been to Rich's house in Pahrump twice and bought some stuff each time. I'm just crossing my fingers this engine doesn't eat a cam!
     
  13. OHC JOE

    OHC JOE Mullet Mafia since 2020

    Yeah I know I used joe Gibbs break in oil...and make sure you prime that motor good before you start it and cross your fingers and toes
     
  14. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    I'm going to slather the cam and followers in moly grease also. With the modifications I've made I'll be doing several oil pressure checks before I actually fire the engine up, have to be sure the lash adjuster galley is getting only 10-12psi and to make sure that the straight pipe I'm putting up to the cam isn't depriving the rod and main bearings of too much oil pressure. If the pressure is low on the bottom end I'll see about installing a restrictor in the tube to the cam, but I'm hoping that isn't necessary.
     
  15. OHC JOE

    OHC JOE Mullet Mafia since 2020

    Jerry has the tube. That goes in the head also yeah oil pressure it the main thing all the way around on this motor
     
  16. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Got some work done today. Finished my oil system modifications, hosed down and cleaned the head to clear out any metal chips, installed the valves and springs, painted the block, head and oil pan and installed the oil pickup tube. I had to modify the oil pickup tube as I decided for this engine to use the 230 pick up and leave the original 250 pickup for the good engine. The difference is the tube is flattened in one spot to clear the throws of the 250 crank.


    Here is a picture of the narrow part of the 250 oil pickup.
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    I heated the 230 tube up with a torch and used a piece of wood as a backing and hammered a flat spot in about the same spot.
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    Installed the pickup tube seal, slathered it in a bit of oil before install.
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    The pickup tune has a hold down similar to a distributor hold down. Put some loctite on the threads.
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    Clears the crankshaft now. I didn't actually check, but it must of just barely rubbed without the mod.
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    My straight brass tube next to the original restrictor tube.
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    Threaded the end so I have a way to remove it if needed.
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    I drilled the oil hole open a hair to the diameter of the brass tube. That's as far down as I can push the tube, it gets real tight after that.
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    Slathered it up with black RTV to make sure it seals.
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    Then hammered it down in the hole. I actually had the head on my wood stove for a good while so the head was pretty hot. I'm hoping it get's tighter as the tube and head become the same temperature. One thing I checked though, once the cam housing is installed it will keep the tube from getting pushed up as the tube does not fit into the cam housing.
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    Started installing the valves.
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    Pretty straight forward stuff. Compress the spring until the keeper slot shows on the valve stem.
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    Install keepers. Always careful with spring compressors, if one of the hooks slips it gets interesting in a hurry. I made sure to wear safety glasses when doing this just in case.
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    Now some gratuitous end of day pictures.
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    Tossed a cam housing on there just because.
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    Tomorrow I'll do some work on the accessory drive, water pump and front cover stuff. Still not sure what I want to do for the paint scheme on them.
     
  17. OHC JOE

    OHC JOE Mullet Mafia since 2020

    looks good man i hope all works out...
     
  18. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Thanks, me too! Small update and a bit more color today.

    Did lots of cleaning today. Pulled apart the accessory drive to clean it up. I removed the stock 30psi pressure relief spring and installed a spare Buick 60psi spring. The white spring in my Skylark actually nets me 75psi with 10w-30. If I find it's too much for the OHC engine I'll start cutting coils off it until it caps out around 60psi.


    Spring comparison.
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    I guess I've settled on my paint scheme. Buick runs too deep in me, I have to have some RED! I'm going to paint a different cam housing Pontiac blue with red stripes and the timing belt covers are painted like that now and drying. The red capped with black kind of just fell out that way. To top it off the distributor cap is black when it goes back on the engine. I actually put the lower sprocket on just to take the picture, it has to come off to install the front crank seal plate. Still have to install gaskets and I'm going to get new bolts to hold the accessory drive.
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    And one more picture just because.
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    Remember this is what it looked like when I got it. I've actually used the 230 oil fill tube and cap.
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  19. OHC JOE

    OHC JOE Mullet Mafia since 2020

    Looks good I have an extra motor also...as soon as I drop the motor in my 49 I will put the ohc back on the stand and repaint it......
     

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  20. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    This post is a pile of updated posts from another thread I'm maintaining, so there is some redundancy.

    Picked up some stuff from the for this build.

    I actually got 8 injector plugs then found a nifty northstar fuel rail and injector harness. I grabbed a coolant and air intake temp sensors as well as an idle air control valve for a throttlebody that was given too me.
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    The nifty thing about the fuel line is how the injectors clip to the line so you don't really need a hold down bracket. I've read that these plastic lines are easily installed and removed when placed in boiling water. I know one guy that has used them on an AMC Gremlin and said it was a piece of cake. I'm going to see if I can source some new line so I can customize the lengths for the OHC engine. It came with a fuel pressure regulator too that will be useful before the turbo install.
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    Found another northstar engine intact while walking around there. I should of grabbed that one too =/
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    Picked up ~18"/$15 worth of new 3/8th and 5/16th plastic line at the parts store in the Help section under fuel line repair, enough to play with and "test" with.

    Also finally mailed out the semi-blank cam I got from Jerry Woodland a couple years ago to a cam grinder for some final grinding. Asking for a "Full Race" grind and will likely cut into the cam core diameter a decent amount to gain some lift and duration. I had to get on this because I have a head at a machine shop to be cleaned, checked, intake dividers welded up and machined truly flat and divided, bronze valve guides and new valve seats. Next step will be porting, new valves and new valve springs. I need to know the final cam core diameter to know what length valve stems to get so I had to get that cam mailed out.

    An update! And a critical mistake identified!!
    Got word and pictures some head work has been completed. I'll let the pictures tell the tail.
    The head cleaned up.
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    Another view.
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    The intakes ports welded up.
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    Time for some gasket matching port work.
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    Harden seats and bronze valve guides installed.
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    So now my critical mistake! It was pointed out to me that my head bolt passage was intercepted by the oil drain back passage. It didn't make sense to me, that Pontiac took the time to give the drain back it's own passage in the block and figured that the head would be the same way, but went and looked, and sure enough that damn passage is opened to the head bolt boss (for no apparent reason) I tapped my oil regulator into. You can see the return passage below the head bolt boss.
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    So for my work around for the time being is on this build I think I'm going to tap the top and bottom of the oil return passage and install pipe plugs sealing off that return. There are three other returns in the head that will have to take up the slack. For the new head I have what I see as two options. Option #1 is to simply move the regulator forward one head bolt as that one does not have a return passage intersecting it, but it does clutter up and/or interfere with the distributor. So if I go that route the good engine will have to start off distributorless, which isn't necessarily a bad thing. Option #2 is to simply find something to sleeve the return passage with and keep it from connecting with the head bolt boss. I'll make that decision later.

    Also, I ordered 32 injector bungs off of ebay so I can start modifying and building intakes for the EFI.
     

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