The Break Down of a '69 Pontiac OHC inline six

Right on buddy ......looks good... And a pain in the ass at the same time.....Jerry woodland is a good dude I've been dealing with him since I was 18.... I'm now 38.... He has helped me out ALOT over the years...

 

A few updates on this one.

April 13

May 3

May 4

May 5

May 6

 

Went and picked up the mother load of "stuff" this last weekend. There is so much I'm not even sure what direction I'll go first, but I'm leaning towards staying the course with the block I'm working on, but possibly using the pistons on the rods and crank I have. Then get one of the heads ported and set up, or may continue on with my current head project and save ALL the good stuff (except the forged pistons) for when I have the turbo R&D completed. To say I am excited is to under state it!

Got a u-haul trailer of stuff! Including 6 blocks, a couple heads, some cams, two '69 Firebird core supports and lots of miscellaneous parts.


Used a ramp, and some help to get the engines in, but didn't have too much trouble with a sheet of plywood and the engine hoist.


A snap shot of most the stuff. The engine stand came with the engine! There are accessory drives, starters, pulleys, tubing, misc. hardware, couple oil pans, etc.


A couple of cams. They may or may not be high-performance, but will check them out later. I already have my turbo cam for my main engine goal.


Cleaned up 250 head. Basically the same head that is in my Firebird now except it has nice new seats. I did get some valves so have to decide how I want to proceed from here.


This head has beehive springs on it. The stems measure ~.100" above spec, so would need to be cut down. I am considering just shaving them ~.050" and with my turbo cam needing ~0.050" taller stems, would put them right in spec. I'd have to come up with 0.050" shims for under the lash adjusters to keep the geometry good. There is probably some wiggle room on the lash adjuster side though.


This is the beehive head, I believe it's a 230 1bbl head. Pretty high compression on a 250 engine, but I think if the chambers are modified the compression with a felpro gasket may be right where I'd want it for the turbo engine. I've been working with a 1bbl 230 head already, so I have something to test with first.


A fully machined block and crank. A set of pistons and rings for it as well. I have a good set of OE rods with arp bolts already. I may confiscate these pistons for the block I've been modifying.


An engine just waiting for a good head... This is just going back into it's wrapping (and maybe more wrapping) and will sit in the corner until I'm pretty much done with all my turbo R&D work. Not sense in risking it on stupid tuning or other mistakes. It has a nice set of forged rods in it, and may even be a stroker engine (off set ground journals with longer rods).



Three of the engines, including the machined bare block, have all the cross bolt bosses cast in. It would likely take a TON of rpm and boost to require cross bolting, but if I ever reach that level of eccentricity I could have main caps made to take cross bolts. 7 mains is already pretty hefty though.

 

Looks like I haven't updated this in a while. Some steps forwards and backwards going on.

I've since removed my fancy home made intake due to vacuum leaks at the flange and re-installed the modified stock intake. I'm going to make a round 2 intake attempt after I get an intercooler mounted in the car to better optimize where the throttle body lands. I learned quite a bit when making that intake so hopefully can use that knowledge to build a better second one. Played a bit with trying to plumb in some piston squirters, but even with 3/16 pipe I couldn't find a good routing that didn't get tagged by the crank, rods or pistons. Messed some more with the oil/air separator to try and clean out the oil that eventually creeps to the intake manifold. No real progress. I just messaged Hector (CARHEX1) to see about getting a few smog pumps to experiment with making a crank case vacuum pump, but the general internet consensus is they seize up or flat out break when oil goes through them. So hence the experimentation. I'm going to try painting the interior and a few other "ideas" to see if I can get one to live.

I opened up the 4L60e I bought a year or so ago. It had minor amounts of crud in the pan, the magnet was virtually clear of shavings, and the fluid had signs of some water in it, but looks like mostly condensation to me. It was stored under a tarp outside when I got it and on a piece of plywood on a dirt floor in my barn afterwards. Nothing overly concerning. I have started with installing a shift kit and will initially be using the stock torque converter that came with the transmission. Interestingly enough, it had all the accumulators replaced with Sonnax pinless accumulators, but the servo was a stock truck one. I have a Megasquirt 2 I am going to use as a transmission controller. It takes more modification than I thought it did, but nothing I cannot handle. I still have to build the wiring harness for it.


Now some exciting news! I bought one of the Sloppy Mechanic's "Denmah" turbo kits from VSracing. Same kit that gets around 600wheel horsepower out of a 4.8L LS engine. I don't expect to make anywhere near that HP, but figure the difference between a 4.8L and 4.2L is close enough to allow the turbo to work in this application. Supposedly it's even a bit undersized for the 4.8L, so all the better if so.



I'm going to do the first install pretty quick and dirty. I'll get some non-mandrel bent 1-3/4" pipes made up from a local shop and run it as a twin scroll set up. Front three cylinders and back three cylinders. If my calculations are right, I have enough fuel injector on the engine to cover about 350 horsepower, and based on 1/4 mile data the engine N/A is making around 175HP. I plan on having the turbo sit right about here. I'll do some clocking of the turbo to get the cold side outlet where I want it for the intercooler. I'll probably require some minor re-plumbing of the coolant and transmission cooler lines to keep them from interfering/melting.


Looks like I'll just have to do some minor hood latch support cutting to fit the intercooler in front of the radiator. Fortunately I have a spare core support to use to reference where I'll need to make the holes for the piping in the car. I'll likely need to re-locate the battery too, which is a bummer, but not unexpected.


And a reminder on how the exhaust manifold is. I've since cut out the cross over, and later I may build my own headers (I have a header pipe kit on the shelf), or even bolt the set of fancy headers I have on. I rather get the fancy headers coated before using them and not ready to spend dollars on that yet. If the twin scroll plumbing isn't quite enough to get it to spool up reasonably, I'll try some EFI tuning tricks to try and move it along better.

 

You, my friend, are the consummate tinkerer. I love it! Of course, this is all weapons grade tinkering.

 

That I am! That I am! :grin:

 

I love to read your posts, I have no idea what you are talking about when you "go long" on the electronic stuff, but I'm still just mesmerized.

Why are you fooling around in Ely, I Google Mapped it and it's lonely looking, instead of working in one of the OEM think tanks? The industry and the aftermarket suppliers have got to be looking for creative, forward thinking people like you.

Keep up the posts and maybe when I hit the lottery I can hire you to build me an off the wall engine.

 

Haha, I'm probably the last person you want to pay to assemble an engine! Actually that is all I really am in that regard, an assembler. I don't even seem to make the horsepower I "should" with them, but it goes back to the tinkering. Living where I do though, I put the miles on them. Practically can't leave town for less than a 500 mile drive round trip. 185 miles to the nearest Walmart and 250 miles to the nearest Target. I'm a Chief Mine Geologist at the copper mine just outside of Ely, it's pretty much what keeps me here though rural life isn't too bad. We produce a bit over a 100,000,000 pounds of copper a years, a few tens of thousands of ounces of gold, by moving upwards 300,000 tons of dirt a day and processing ~50,000 tons a day for copper. All I ask is all of you go out and buy several pounds of copper each month to keep me employed :laugh:


Each one of those steps is 50ft, aka 5 story building. The mast on that drill is over 80ft tall, and the tires on the haul trucks on the right side are 12ft tall.

 

Wife asks "have you hit China yet"?

That's a deep hole.

 

I'm waiting on some intercooler plumbing parts, and decided to make another go at building my own headers. I have some 1.5" primary pipes that I thought are too small to use as a high performance headers, plus I have larger header pipe on hand as well as an assembled equal length header that has a larger primary pipe diameter, so didn't think much about using them. But now, given I'm trying to make a twin scroll exhaust setup, the guidance I've gotten was to keep the secondary pipe fairly small, so with that in mind I could keep the primary pipes smaller as well.

So the plan is to use the 1.5" primary pipes into two individual collectors, keeping them as equal length as I'm capable of, then run two 1.75" secondary pipes to the T4 flange, and again keeping them as equal length as I'm capable of. I have several 90 1.75" bends on order to get the piping to the passenger side of the engine. I was going to simply have a local shop bend me up a few non-mandrel 90's and plumb off the exhaust manifold, but I was getting the run around by the shop I was going to use. So I'm abandoning that idea until I get frustrated with these headers, lol.

When I digitized the exhaust ports to calculate the area, they averaged 1.82sqin, and 1.5" pipe should be around 1.77sqin, so fairly close. I'm going to keep the pipe tucked up along the top of the port as best I can and stretch the metal downwards from there. I believe there are two headers worth of pipes, hence the huge pile of U's. I'm currently on hold for progressing though until some parts come in to build a collector. I need the collector location to be established to really start on the headers.

 

Progress! First set of headers I've ever attempted to build, but so far I'm satisfied with the progress. Before I stitch the tubes together I'm going to get a smaller wire for my welder to reduce the chance of blowing through the metal. Once I have the tubes welded, I'll build a pair of collectors down to the 1.75" pipe, then do final metall stretching and welding to the flange.







I'm going to be giving it more thought, but I think this routing will let me use the pipes I have as is. I just need another 90 coupler or two. This routing will require just one hole through the core support on the driver's side. Then I'll build a new intake manifold and line up the throttle body with the tubing.

 

Been a long time since I've updated this thread. Mostly from moving at the end of 2016 and really having long passed simply tearing one of these engines down. Now I'm building up a serious one with the goal of making it to Drag Week 2018.

Got a head ported, with some good valves installed.


The chambers.


Intake ports.


I picked up this unfinished prototype intake, intended for a Chevy L6, to finish for the Pontiac L6. Three or four were casts, the inspiration for the design was based on my sheet metal intake.


Unfortunately the runners were too narrow to match up to the recently ported heads.


This was solved by welding 1/4" aluminum plates to the runners.



The welds cleaned up.


The ports opened up to match the head.


I picked up this 4" turbo down pipe from Summit's clearance rack for $20.






I am ready to install the 4L60e I put the shift kit in over a year ago. I've purchased a Microsquit transmission controller and wired it in. I've also picked up a pair of mid-2000 4L60e's for a grand total of $160 so I can see about rebuilding one myself and possibly use one as a core for a performance transmission shop.



I've got a set of scat rods and ross flat top pistons showing up this week. I've ordered an IO extender board (Input/Output) so I can monitor a ton of things on the engine/car to run on the safe side of the ragged edge. Going to be monitoring and logging crankcase pressure, pre and post intercooler pressures and temps, coolant pressure (watching for the head lifting under boost), engine oil pressure and lash adjuster galley oil pressure.

I just started the process of pulling the front end apart to change out the cooling system and install the intercooler. In another Summit clearance rack deal I picked up a Goodmark 2nd gen F-body 2-row aluminum radiator and "spare" replacement Meziere water pump motor (as well as a 4L60e torque converter). So I'll be fabricating brackets to hold the radiator and intercooler in place, as well as possibly making holes for the turbo cold side plumbing. My wife got me a sizeable Summit gift card for Christmas so I can buy a 55gpm Meziere water pump to replace the 21gpm pump I had on there.



Fun fun!

 

Some goodies showed up yesterday. 6" SCAT rods and some forged Ross pistons to go on them. I plan on having some valve reliefs cut into the pistons to keep the engine non-interference. They are "thick" crowned for nitrous or boost use.





Then woke up this morning to see the throttle body side of the intake manifold has been worked on.

 

Man bro still on this car crazy.
Hey I'm looking for some man a fre intakes
I found an old school Foundry and the guy in there said he can probably make some.
I also posted on the ohc6 board

 

Some minor updates. Just a bit here and there. I have everything I need to assemble a short block. I have the head back with valves, but need to source valve springs and retainers to complete it.

The intake was finished. Unfortunately my header runners interfere with the intake, so I am going to make a new set of headers, and step up the pipe size a 1/4 inch.


Dowel pins were added to the head to locate the intake reliably. This picture was taken before final port matching, pretty close out of the gate.


Mocked it up on one of my core engines to get an idea where the throttle body would land for the cold side plumbing.


Mounted the intercooler and 2-gen F-body radiator. I need to get new bolts for the upper IC mounts, and waiting on some rubber radiator mounts to finish the radiator mounting. I was surprised at how little trimming the hood latch support needed to clear the IC.




Hole sawed through the core support and just need another 90º coupler and to shorten the pipe a bit and it should line up perfectly with the throttle body. I am tempted to get a carb hat and put a little boost to this engine, lol.


A little too far forward to make a good inlet for the hood scoop.


I'm at the point of trying to figure out where to fit the water pump because the hot side plumbing has taken over all the space I used before, and the new pump is way larger. Once I have the new pump installed thought I'll be able to go back to driving the car some as I work on it.


Since this picture, I've remade the turbo mount, pulling it forward and stronger, and I've trimmed the exhaust tube by about an inch to pull it away from the firewall.

 

This is AWESOME
Long live OHC's

 

Ridiculousness is still on-going. My welding could be better, but should get the job done.



Headers built.


4" pipe to the rear axle, down to 3" over the axle.

 

That think looks wicked sweet

 

Oof, I just up and stopped updating this thread right as it had the potential to get really good! Unfortunately the machine shop did not get my engine short block back to me until a month after Drag Week, and I am only now putting the finishing touches on the new engine to install it. Though it took me cracking cylinder #3 to finally make the swap, lol

I did make it to Drag Week 2018. Drove across the country, completed the ~1,100 miles of Drag Week, then a friend towed my car to his place in northern Montana where I eventually picked it up and drove it 900 miles home. The short version is, I was in such a rush that at some point a wire got pulled in the harness that disabled coil #5 and I didn't notice the whole 2 weeks I was in the car. The engine always consumed oil, so the plugs didn't show the miss, the inline nature of the engine didn't vibrate with a miss, and the turbo was a new addition, new sound and an exhaust note dampener and I didn't pick up an audible miss. After I got the car home I was trying to figure out why the turbo was so laggy, which I assumed was from being oversized (I bought a kit for an LS engine), and at some point realized #5 wasn't firing. Got that fixed and it really really woke up. Especially at 10 psi, but it does still have a fair bit of lag down low. Here's a few pictures.

DW2018. Best run was 15.17 seconds at 93mph. I figure it was making around 240hp on ~7 psi carrying a dead cylinder and flooding the other's with fuel because I was trying to fix a "lean" condition.






Driving around over the last few years.




I got concrete out back a few years ago, which has made working on all cars very nice.


A few video's testing out the boost, rev limiter and two step. I eventually learned that the rings really did not like the spark cut rev limiter. It would pressurize the crankcase immediately.
https://www.youtube.com/shorts/g9lXrICAzOc

https://www.youtube.com/shorts/BWsrUxhPmJc

https://www.youtube.com/shorts/5CsU1qLkH1Q

https://www.youtube.com/shorts/uLhRBNbLiTw

This was after it cracked cylinder #3.
https://www.youtube.com/shorts/zQGO2N19eoQ

Wah wah wah.....

 

New engine is pretty much all together. I'm wrapping up a few modifications from stock. I've made a full length windage tray, which required adding a 1/2" spacer on the oil pan. Every time the car hit second gear the oil pressure nosed dived to under 20psi, so I wanted to have some better oil control and improve windage control as well.



Bearing clearances are really tight. Tighter than I'd like, but not really much I can do about it, so going to run a good thin oil, improve the oil feed and hopefully its enough. After pulling the other engine apart I feel better about crank flex.


Pontiac didn't mess around, the OHC L6 used 1/2" bolts on the mains and heads. I've replaced them with studs, but the Chevy L6's use 7/16" bolts.


I've added EGT sensors to each port.


Full length windage tray.




With the windage tray and pan spacer, the stock oil pickup tube wouldn't be ideal. With some testing I've found the accessory drive oil pump can be modified to accept an exterior oil pick up line, so I modified an oil pan for an external oil pickup line and looking at my Buick 455 SRE oil pan, I added some front and back baffles somewhat patterned off it (now only if my welding was as good! lol)






I've got a few more minor things to do on the engine, and in the mean time I've been completely re-doing the EFI wiring.