Inliners International Forums General Discussion Blown and Injected Hacking together EFI on an Pontiac OHC Six

I have the injector bungs available in aluminum and steel if you need them and externally threaded if you would rather thread them into the intake instead of having to rely on epoxy.

Interesting!

If steel I don't need it externally threaded. How much for 6? 12? Then out of curiosity for future projects, aluminum ones externally threaded and what is the thread size and count?

The unthreaded aluminum or steel are $3.50 ea. Haven't decided whether to offer a threaded version in both aluminum or steel or just one of them. They will be slightly higher cost though of $4.50 ea. I planned them to be specifically for those wishing to convert a stock intake or aftermarket intake to EFI.

Thats a smoke'in good deal! I'd use the steel for my sheet metal intake and the aluminum for drill and tapping a cast iron or cast aluminum intake and threading them in.

PM me some payment details and I'll take a set of 12 steel non-threaded ones.

PM sent.

I pulled an intake spring off the engine and all my assumptions on it's size were bad, lol. Currently looking at summit it's a Comp 984 spring, which Amazon sells 12 for $40. It should give me around 120lbs on the seat and 220lbs over the nose. That should help with valve float compared to stock spec's of 100lbs on the seat and 175lbs, if the springs still test to "new" standards.

While I had the spring off, the valve guide seal on number one looked pretty good, so I wonder if the other's look as good. I'll find out when I pull the engine apart in a couple weeks and change the springs.

I pulled the trigger and ordered the springs. Looks like my ball hone showed up yesterday at 6:30pm. I was out in the barn pulling the spring when it arrived and noticed it this morning as I was backing out of my driveway to head to work.

Here is a nice throw back Thursday picture. This is the engine that is currently in the Firebird and taken at my friend's house just south of Phoenix Picked it up for $200 with 2-speed trans. Left the trans at my friend's place for scrap.

Just curious if you were getting valve float & if so what RPM were you running it up to?

MBHD

Power started to drop off at 5,300rpm and the engine refuses to go above 5,800rpm.

I want the MegaSquirt to control where it's limited (within reason). Though most agree, historically, the ports and such 5,300 is about where it starts choking off. Pontiac humorously put the redline at 6,500rpm for these engines. I'm probably going to port the head when I have it apart to try and gain some more airflow/rpm. I'm putting the top end back together tomorrow morning with the E-cam, that has more lift and duration.

What is the duration on the camshafts @ .050"?

MBHD

No clue. The only spec I have is the advertised number of 244º.

You can see the interesting shape of the cam lobe in this picture:


And you can see the chart about valve opening and closing rates being "faster" than the conventional in block cam. At least OE cams, probably fairly similar to roller cam's.

Yeah, those OHC have fast ramps on the cam lobes.

244 advertised duration is pretty meaningless.

I would think the camshafts are low duration & therefore will not rev that high.


It might have 200 degrees duration @ .050" but probably less than that.

MBHD

Car is up and running with the new cam. Fired right up. I haven't taken it out on the road yet though. On the surface, it sounds the same.

I've also changed up the alternator bracket again, utilizing the stock adjustment bracket with some spacers.

I've been driving it around town yesterday and today and the off idle bog from not having a TPS sensor was bugging me. So I cut and drilled a piece of angle iron and mounted a mid-80's sensor to the Holley carb/throttle body and used a small piece of cruise control chain to connect it. With minimal tuning of the accelerator pump shot it's running pretty good and 90% of the bog is gone. I still have a bit of work to do, but it's pretty good now. And of course the first time I wired it up it registered backwards so I had to reverse the power and ground wires.

Closed throttle


Wide open throttle.


Since I am not gaining the 1.5 points of compression with the 4bbl cam, I'm going to go install the adjustable cam sprocket I have and set it for a full 8º advance. Should help the low end and bring the power level down the band a bit. Might even pick up a few mpg's.

I was always wondering when you were going to get tired of driving that way w/no TPS.

Are you trying to see if it will run better for the 1/4 mile?
Or trying to get better mileage by using a 4 BBL camshaft?

Trying to jar my memory, but didn't those OVC engines have camshaft oiling problems?

How much more duration is the 4BBL camshaft supposed to have over the 1 BBL camshaft?

When you install a turbo, are you using this same 4 BBL camshaft?

Not sure what your goal is?


MBHD

Installed the Sprintbird cam sprocket set to maximum advance. The nice thing about the engine being a non-interference design is there is no risk to valve piston contact in the event of a goof up. I ran the engine before picture, so the timing mark doesn't line up in the photo.



and just a shot of the whole engine bay with the timing belt cover off. I installed the cover after the picture.


A short video of it running with the timing belt cover off.
http://youtu.be/Kb0T5-OFJnU

I've taken it for a spin around town and it's running pretty good. It is nice to have that bog gone.

Don't know the at 0.050" duration, but advertised is 244. I have a different cam for the turbo engine. It's a re-grind (because there are no cam cores available)but it has increased lift and more duration with a slightly split pattern on the duration.

If I end up installing the turbo on this engine, because I can, it will be with this cam. Long term goal, for the next engine build, is 600HP with a turbo. With a similar ground cam as my turbo cam (only difference is a wider LSA and slightly more exhaust duration) folks are making 300-320HP naturally aspirated with these engines. With more compression than I'm going to run though.

Primary goal for the turbo engine will be drag racing. Currently is just drive it often and to make it go faster and I'll see what the effects to mpg's is and decide if I want to compromise back to mpg's.

The stock oiling system was crippled by the factory to keep the lash adjusters from crushing the cam from too much oil pressure. I've remedied that by removing the two oil restrictions, upping the oil pressure relief spring from 30psi to 60psi and running an external oil pressure regulator to just the lash adjusters.

Nice!
Personally I like the look w/no cover over the cam gear. Good looking cam gear!

Looks like it needs a lot of tuning from the short vid?

Does it seem like it is fast at all?

ET estimate?

Maybe it's just me, but, It just seems this project is going in the wrong direction to go any quicker or better mileage (other than the cam advanced)
4 BBl camshaft install on a 1 bbl engine, w/ low compression.

I read you said this "Currently is just drive it often and to make it go faster "
But installing a larger camshaft usually does not make a low compression engine go faster.

I don't get it, it is ready for a turbo now, not later.
Just run low boost, & watch for knock.

But I guess as long as you are having fun tinkering with it, that is all that matters.

OK , I'm done .

This is essentially the "Science Fair" project. An experimental mule engine. The long block is currently just a $200 craigslist engine I put new gaskets in. I did lap the valves on my bench and replace one exhaust valve. With the radical oil system modifications I've made, the reverse flow cooling setup and the EFI patch work, I wanted to make sure it all worked prior to spending good money on a good engine.

With the 4.56 gears it feels like a rocket ship! I'm going to take it 1/8 mile racing in July and I'm contemplating taking it to a chassis dyno as well. But currently, it is slow, and I don't have any estimate for ET's.

I'll be driving the car and R&D'ing this engine while I build my good engine. I already have a second block with cylinder walls that sonic checked twice as thick as this engine's, like wise I have a second crank, re-conditioned forged rods, a head that's been trued up to a true 12 port and had bronze valve guides installed, as well has hardened seats. Its ready to go to a porting shop at which point in time valves will be bought and the seats cut. I've bought a set of forged pistons already, just waiting on delivery. And of course the turbo camshaft I've mentioned a few times. Even with all this stuff, the turbo engine is at least a year out, so I figure I'll be driving this engine in the mean time so I may as well make an attempt to get it to quit blowing oil, so doing a quick R&R on it next month.

I got the e-mail Friday my 3/8 thick intake and exhaust flanges are done at the water jet company in Las Vegas. I'm going to pick them up June 9th when I'm driving through. I will start working on fabricating my turbo intake manifold at that point. It too will be bolted to this NA engine. Making sure everything fits, etc. As each piece comes together this engine very well may get a turbo put on it for a bit. As I'll want to make sure the intercooler lines up, plumb the turbo, etc. But there are some big costs that come with not just the turbo and intercooler purchase, but I will be getting a new radiator with built in 55gpm electric water pump to clear out the hoses I currently have and make room for a turbo to be mounted on the passengerside. I'm still debating on if I'm going to run two exhaust pipes to the turbo for a true twin scroll, or if I'll simply run one from my current collector.

Same guy that ported and re-shaped the chamber on this one is going to do my head.

That cyl head looks like the ports are huge. Looks nice.

What are the port measurements?

Are they opened up a lot from stock size?

MBHD

They are opened up a bit and cleaned up a lot. I don't recall the exact measurements off hand but I think they were essentially gasket matched to this gasket.

(this is my cleaned up head in the photo ready to go to the port shop)

This is what the head on the engine currently looks like. No work done to the ports.


I scaled the pictures best I could and cropped them next to each other to show the difference in the chamber shape. The top head is currently the one on my engine. Basically opened up around the intake valve to unshroud it.


Hard to believe this engine looked like this when I picked it up a few years ago.

Cool, & Thx for the pics.

Those ports appear to be pretty good size.

I would not think to open up the ports to gasket match them.
They look too big already, might be low on port velocity?
Hard to say, by just looking @ the pics.

Maybe if you had a measurements of the intake ports & exhaust ports I would have a better idea on just what size those ports are.
Valve sizes in, ex? I forgot.

I would definitely not lower the floors of the ports. You would want to leave those floors alone, unless there is a big mismatch between the intake manifold & the head.

On the 1 BBL intake , are the ports divided?
It's been so long since I have the seen the 1 BBL & 4 BBL Pontiac Sprint 6 intakes side by side I cannot remember how they looked.
Got some pics?

Did the 4BBL Sprint 6 have better con rods than the base line 1BBl Pontiac 6? I heard they did but never confirmed it.

Your paint job on the engine makes it look new.

MBHD

I just got an intake/exhaust flange water jetted and when I pick it up I'll port the head to match the flange. Then using PipeMax I'll get and use the taper and runner length for my sheet metal intake. It'll look similar to yours but far less refined, lol.

1.60" exhaust valve. The 1bbl intake is not divide, the 4bbl is, and both heads are divide EXCEPT about 1/8" gap short of being trued up with the mounting surface. My turbo head has that welded up and machined flat already.

Any rumor on the rods is complete crap. Pontiac re-designed the rods in later engines, but the 1bbl and 4bbl engines of the same year got the same rod. And they are forged, and they are forged of the same steel as the Chevy 230/250 engines per the numbers in the service manual. The 1bbl and 4bbl got the same piston as well, though the part number for the rings show the 4bbl got a better second ring (same top ring).

Paint = Lipstick on a Pig =P As they say, rattle can rebuild? lol

Here is my attempt at chamber re-shaping. Over all I am quite pleased. This was about 30 minutes worth of work. I had to account for a bigger/deeper chamber than in the picture because the one in the picture is a high compression head. I wonder if I should smooth out/open up the other side of the intake valve as well? Who needs compression anyways?

Hard to say on where to open up the chamber.

It depends on throat angles, valve job. Weather air swirls and follows air paths into the chamber or is very turbulent going into the chamber.
As I said before, not good at explaining how this all works, I do know how it is supposed to flow into the chamber though

Sometimes, a valve will look like it is pinched off & is so close to the side of the chamber, you relieve the chamber wall & it does not really help, well that is because that is not the way the path of air/fuel is entering the chamber.

From what the ported guy did to the other cyl head chamber walls, it looks like a lot of airflow enters the back side (close to the spark plug hole) of the chamber. That is how my cyl head picked up a lot of CFM, but mine is aftermarket.



If that guy knows how to port those Pontiac heads & is rebuttable I would just try & copy his porting techniques.
Or were you going to have him port it?

As far as compression goes, I would shoot for 8.5-9.0 compression ratio.

Again, not too sure you should go as big on the ports as the gasket is? Unless your flange is made smaller than the intake/exhaust gasket.
Bigger is not always better.

MBHD

Hank, your comparing his ports to a siamese head that are way too small for those Chevy engines. A 250 has the same cylinder volume per cylinder as a 350 SBC does. And these OHC engines were designed for HP in mind, while the 250 Chevy was not. I bet if he was to cc an intake runner, it would still be smaller than an average stock SBC runner.

I will go to the flange size on the ports, regardless of the gasket size.

The guy that did the fully ported head in the pictures has R&D'd it with a flow bench to get to that shape, so it's what the air wants in this setup. Remember the valves are also canted at 14º off vertical, so the air is definitely racing towards that part of the chamber.

I took a dial indicator and some calibrated rocks and set the intake valves at 0.438" lift, which is how much lift my current cam has to show the difference. It was recommended to me, if I can, to get 0.020" shaved off the bottom of the head if I can. Hmm, I may try that after I port and re-shape the chamber on my running head, I'll see if the Machine Shop in Elko (2.5 hours away..) can shave the head in the same day. In the past they have been able to do same day work for me when scheduling it in. I need to run some numbers, but l don't think it's possible to bring the compression up too high from shaving the head while using a head gasket that is around .030" thicker than the stock steel shim gasket that is impossible to get now.

I adjusted the color for more contrast because the sun was white washing it out.


Then I brought it indoors. See that step in the chamber above the intake valve? That step is what lowers the compression, the 4bbl head doesn't have that step. So I will likely smooth that step out around the intake as well.


You can see where I was working with the dial indicator as it scrapped the carbon off the valve on the right. I just shifted the set up left to do the other valve.

Look's good. Wish I'd known you needed intake and exhaust flanges for the OHC engine.

They are a bit different than the Chevy L6. For $90 I'm essentially getting a 3/8th thick steel gasket. Which then I'll have fun cutting up into the individual flanges =P I bought two of them so I can build one intake/exhaust and have a spare if I need to do it again.

I pretty much just looked up a place that does water jetting in Las Vegas as I pass through there from time to time. I'll keep you in mind when the next thing that I need cut out of steel pops into my head.

Called the machine shop in Elko and he said that it would be no problem getting same day turn around time on getting the head shaved on June 20th. I'll cc the chambers before and after I port them (namely after) and calculate the compression numbers with the different head gaskets and such to see how much I want taken off.

So the plan is:
June 5: Drive 475 miles to California.
June 6-8: drive around 150 miles
June 9: Drive 475+ miles home, stopping in Las Vegas to pick up the intake/exhaust flanges for this engine from the water jetting company.
June 14: Pull engine, start tear down.
June 15: Re-assemble engine from head deck down.
June 16-19: Port, port and port the head. Lengthen and clean up the engine wiring harness. Probably go to the friction tape like Squirrel.
June 20: Shave head to regain compression.
June 21: Re-install head and set engine in car.
June 22: Finish hooking everything up and hopefully start it up to take to work on Monday.

Be ready to go on the Car Craft Anti-Tour July 25th and down the 1/8 mile track.

June is going to be busy after all!

Piston rings and bearings showed up today. Interestingly enough Northern Autoparts sent me 8 rod bearings. The included invoice says 8, but my Amazon order definitely shows 6. Oops. Tracking says my engine gasket kit and valve springs are due here tomorrow.

Sounds like fun.
Found you on another forum.

I'm planning on going. I'm a bit indecisive if I am going to bring the Skylark or the Firebird. I'm leaning towards the Skylark due to wanting to run at a track and the Firebird's oil consumption issue, but a lot can change between now and July!

http://www.bangshift.com/forum/forum/bangshift/general-discussion/925567-car-craft-anti-tour-2014

http://www.bangshift.com/forum/forum/ban...ohc-six-project

What does the Skylark run?

MBHD

I'm all over the internet =P Bet you can find the Firebird project on at least three more forums =P


I don't actually know. The goal was run as close to 11.50's as possible. It weighs 3,800lbs on the nose with a full tank of fuel and me in it and the quickest it has ran was 12.95 at 108mph and a 1.9 60ft(full 1/4, the event in July is 1/8 mile). It's a 462 big block Buick, aluminum heads, 10.3:1 compression, a relatively small roller cam and roller rockers, full EFI/coil pack treatment. Two things limited it in the past, one is it would start leaning out above 4,000rpm and was at a dangerous 15-15.5 :1 AFR by the end of the run, but fortunately didn't hurt anything. I was out of fuel pump capacity. Kept upping fuel commanded, and duty cycle would increase, but AFR's wouldn't drop. The second was I was running 3.42 gears in a nearly stock GM 8.5" rear, so I left the line with a light launch and I was crossing the finish line at 108mph, but only 4,800rpm. I shift about 6,000rpm.

So changes I've made since the 12.95 run. Second fuel pump staged in, had the heads professionally ported, from stock 1.55 rockers to 1.65 roller rockers, rear axle swapped to a 9" with a true trac carrier and 3.89 with aftermarket axles. I should no longer be running lean, I should be able to launch much harder, and I should be crossing the finish line at 5,500rpm or above. I intended to run it all out in Drag Week last year, but 600 miles into the trip getting there my pressure plate started siezing up and I failed to get the car to the event. I had over 20,000 miles on that pressure plate, including Drag Week 2012. Fluke? I have a new clutch set in it now and is working great. Oh, and I added electric cut outs to the exhaust to run open 3" exhaust instead of the dual 2.5" pipes that were on it.

The Skylark is the car I got when I was 16 and starting in 2008 had become my test bed for all my EFI and performance stuff. You can see in an earlier post, I tow small trailers occassionally with it too. I've put around 80k-85k miles on it since 2008. Basically my daily driver when it's not snowing or down for upgrades/repair. It's in the parking lot here at work right now. It gets 17-18mpg on the highway (with the 3.89 gear), which is about the same as my '07 Silverado with a 6.0l and 3 mpg less than the Firebird got with 1bbl cam.



Right after I went distributorless


Pictures to big to insert. Folks joke I have the engine installed with velcro and wing nuts because I have it out practically annually for upgrades and it only takes me about an hour to pull the engine/transmission.
https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-prn2/740444_4737397786544_1507922316_o.jpg
https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-prn2/740229_4737742315157_92691588_o.jpg

Looks like a nice Buick.

Was wondering what size injectors are you using?

I know on those brass fuel fittings you have on the fuel rail they are highly restrictive. The ID gets real small in the 90 degree turns.

3800 LBS, time for a diet?
Does it have those 5 MPH bumpers w/gas filled shocks?
What trans are you using? 5 speed?

A guy on another forum I go on got a crew cab 6.2 Silverado.
he shows it gets 17-18 in the city & 23-24 MPH on the highway.

A co-worker just bought a 2014 Silverado double cab & told me he is getting 31 MPH on the highway w/a 5.3.

Those cylinders shutting down is really picking up the mileage.

What is the Eaton supercharger for, the 6?

MBHD

It's a street car, heavy bench seats, steel wheels, the OE bumpers, the A/C works, etc.

It's a TKO-600 5-speed.

The Eaton was an idea originally for Jeep Cherokee I had with an L6. I've since gotten rid of the Jeep and never made any progress on adapting it to it. So it sits for a maybe some day on something project.

I realized that it is a street car.
But trying to run 11.50's & weighing 3800 LBS is asking a lot out of that Buick.
It's not a BBC

Just suggesting something to help you run your numbers.

Having open dump 3" cutouts is going to change your A/F mixture by a lot. Not only that, most tracks have to be a certain DB level, if it is too loud, they will not let you run.

I thought B.O.P. like to run tall gears, they are torque monster engines.
Not sure if the lower gears will help, you might spin too much, can't fit a big tire in there.
Just thinking out loud. Don't mind me.

After you had the heads ported, what did they flow?
What is the guys name that ported them?

MBHD

Jim Wiese from http://www.trishieldperformance.com/, he does all Buick stuff.

It should have the oomph to get me there, or close enough. The cutouts don't change the AFR's that significantly. I've checked plenty of times.
http://youtu.be/5lQ2fpHvCSE

I'm always monitoring how it's running.
http://youtu.be/RGROrwcl-LY

In any case, there is pretty much no time out on the street I can aggressively put the pedal to the floor without the tires starting to break loose on the pavement, so plenty of fun for street driving. And as I said, it gets 17+ mpg.

Back to the Firebird. I properly re-timed the cam, it looks like with the thicker than stock head gasket on it the cam was timing was 1º advanced. So I dialed back what I set it too on Monday and set it to what should be 4º advanced. More realistic setting.

The valve springs and engine gasket kit arrived today, so I have everything I need to rebuild the engine now.

Keep us posted!

Let me add some comma's.

"In any case, there is pretty much no time ,out on the street, I can aggressively put the pedal to the floor without the tires starting to break loose on the pavement, so plenty of fun for street driving. And as I said, it gets 17+ mpg."

Basically in the first four gears on street tires if the pedal is on the floor the rear tires have no traction. Either on the track or on the street. I've never met a person with a carbed 450+ cubic engine engine cranking out 500+HP getting over 12mpg. Especially with steep gearing. Being significantly lean is why it did not make the power before, that and being nearly 1,500rpm under it's powerband for half the track.

I've done plenty of idle, cruising and WOT blasts with the cut outs open and closed. No video, but plenty of datalogging. Not hurting for data in that respect. Believe me I was expecting a change, but it did not happen. I think most people get an AFR change from reversion up the collector to the sensor, my cutouts are almost three feet past the sensor, so no reversion issues messing with the sensor reading. That and the EFI compensates for efficiency changes far better than a carb.

Fortunately the guy doesn't need the website to stay busy, he's got enough backlog of work from reputation.

I was merely saying, the website does not work on any link.
When you post a link to a website normally you would go to it , see what they offer, what they have done, customers cars etc, his website,,,, nothing.

MBHD

We're pretty far out in the weeds.

Getting back on track. I've ordered an HHR fan/shroud assembly for $54 off Amazon with free shipping. I wish I had thought/known about it sooner as the fan I have on there is a 1200cfm unit that cost me $56, and the HHR one is a 3,000cfm unit and comes with a shroud for even better efficiency. I should be saying good bye to getting warm at a stop. Its never gotten hot driving, nor actually overheated on me, but it's made me wonder a few times if I sit in 30+ minutes of Las Vegas traffic this summer would it over heat or not.

I've cleaned the shop area out so when I get back from California with it next weekend I'll be ready to go for engine removal, overhauling the bottom end and doing the porting work. While sorting stuff I found the scrap sections of the pipe I used to make the exhaust collector pipe and I thought it was 2-1/4" pipe, but it is actually 2" OD pipe, so I'm now I'm seriously considering going through with plumbing my turbo system as a true twin scroll system. Still haven't evaluated what type or size turbo I'm going to get yet though.

Ready for work. I have the new gasket kit, rings, bearings and valve springs on the counter in the back and the metal table cleared for the head work.

(should of seen it yesterday morning, couldn't even see the floor from all the tools, parts and packaging scattered everywhere)