I had my engine built in 2006, and chose an entire valve train from Comp Cams. I actually picked it up from Year One just outside Atlanta while in the area visiting family.
From the start I had weak vacuum, resulting in non-working power brakes. I've tried a few things, including changing the intake as there appeared to be a slight crack by the vacuum port, changing the valve timing on the crank sprocket as it was originally installed 4 degrees retarted, a vacuum pump that shook the entire car, and finally a vacuum canister that kind of gives one decent shot at power brakes.
As seen in a previous post, I picked up an entire cruise control system from a 69 Parisienne, and checked with the guy that rebuilt my transducer. He said the cruise system needs 15" vacuum, or he could rebuild me another transducer for diesel engine use, they only require 7".
Well it's either add another band-aid, or reduce my cam.
So, it's time to change the cam. By checking with Comp Cams, they suggested staying in their Extreme Energy line, but going to the entry cam, instead of the all out one I presently run.
I'm part way through, but here's a before shot (from August 2012 when I was the feature car), and after about 2-1/2 hours of effort yesterday:
That big 4 core rad had some weight to it, and I'm not really looking forward to lifting the intake out.
I am interested in your process of changing the cam "in car" and the cam selection you will eventually use.
I have a Comp 270H Magnum in the 396 and I am only getting about 13' vacuum so my power brakes are a bit shy on vacuum. I am tempted to go a GM L34 - L36 grind of 3883986 by Crane which seemingly should provide factory like vacuum. But, that 3883986 is an old grind so perhaps something is a bit better than that particular grind.
I didn't do much on Sunday, just removing the harmonic balancer and distributor. Next up is a toss-up between intake or timing cover.
Comp Cams suggested going with their Extreme Energy 206/212, part # 11-230-3. It's RPM operating range is 600-4,800. This cam is a huge step down from the Extreme Energy 224/230, part # 11-242-3, RPM range 1,600-5,800, but likely the one I should have chosen back in 2006.
I changed the cam a couple times in the early 80's in this engine back when it was in its original 70 Parisienne. If I recall, there was just enough room to slide the cam out.
Comp Cams suggested going with their Extreme Energy 206/212, part # 11-230-3. It's RPM operating range is 600-4,800. This cam is a huge step down from the Extreme Energy 224/230, part # 11-242-3, RPM range 1,600-5,800, but likely the one I should have chosen back in 2006.
The Extreme Energy 206/212 @ .050, part # 11-230-3 RPM operating range is 600-4,800 and the lobe separation is 110, lift is .470 / .475. The info says more vacuum allows an increase in duration for improved performance and assists power brakes and best performance with aftermarket intake manifolds, headers and lower gear ratios.
Clint, just wondering which rear end are you running? And is your trans a stock TH400 a with stock converter?
How are you removing the timing cover Cam? Are you lifting the engine to drop the front of the pan or just prying it out of there?
I just leave the pan as is and pry the timing cover out. The dowel pins aid in getting it back on properly.
I would be worried about getting it sealed up properly that way. Maybe I'm just paranoid.
I did it that way back in the day, and even when I had the timing cover off about a dozen years ago to adjust the crank sprocket. I just be mindful of using a little silicone in the corners where the cover joins the block & pan.
Interesting read, a lot of interesting comments and ideas as to what each of us have done with our 454's .
I too built a 454 Gen Vi engine using the same 781 iron heads, mine were polished and ported as well , heads were built with 2.19 Int and 1.88 exh valves. I used a Comp Cam as well , part # 01-418-8 (37). Gross Lift is .510 Intake and Exhaust. operating range is 2200 to 5800 rpm. Duration @ .0.50 is 224 Intake and 230 Exhaust, Hydraulic lifers etc etc. The engine when dynoed produced 541 ft pds of torque @ 2950 rpm and only 310 hp to do it !!. We did 14 more pulls on the dyno and the highest rpm and torque achieved was 550 ft pds @ 4150 rpm. At 5100 rpm the hp maxed out at 497 and the torque dropped to 501 ft pds.
When I was selecting my torque converter for my TH 400 ( built) I referred to a statement that was written by B&M , " According to B&M the Stall speed of a converter should be rated at about 500 -750 rpm less than the engines peak torque RPM" . As mentioned , mine was achieved @ 2950 rpm , so I selected a TCI converter with a Stall of 2500 rpm, result is very good no slippage, very tight and the transmission temperature gauge sits on 100 Degress F. ( gauge can' t read any lower). BTW, The trans cooler is seperated from the engine.
With regards to the vacuum issue and power brakes I used a smaller 8" dual diaphragm unit with disc brakes all around and I may be lucky here, but mine work really good.
good luck with your choices and project.
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New Brunswick , 1950 Pontiac Silver Streak 2 Dr Sedan, 1967 Beaumont, 1985 Sierra 1500 One Owner
12 bolt rear w 2.73 gears. Turbo 400 w stage 2 shift kit and stock converter.
Similar to my setup but I think I have a 2.56 and my trans is a TH400 no mods.
I am certainly no cam expert by any stretch of the imagination however I have been researching this area and as I mentioned, the 270H Comp Magnum in the 396 with 110 lobe separation is only pulling 12 - 13 of vacuum. From what I read, tighter lobe separations like a 110 give less vacuum but offers other performance characteristics and lopey idle while wider lobe separations like a 112 - 115 gives more vacuum but you lose certain performance characteristics and gain a smoother idle.
If you look at the old 3883986 L34/ 36/ 78 grind that is currently reproduced by Crane (969391) and Howards cams (127061-13), they are running similar lift and duration as the Extreme but wider lobe separation of 115 and 113 respectively, and we know Mark IV's rolling off the factory floor with the stock 3883986 grind provided adequate vacuum to power the brakes.
Now, having said this, the Extreme Energy cam that you are looking at is designed for lower RPM operation of 600 - 4800 where as the Crane is 1500-3800 and Howards is 1200-4600.
Long story shortened, I am very interested in what your cam selection with a tight lobe separation of 110 produces in terms of vacuum once it is up and running.
Well I scrounged up some ambition after work today and pulled off the timing cover & intake. I took a couple shots of the timing marks on the crank sprocket, as some may have never seen this before. This is a Comp Cams 05-395A timing set, and can be installed at 4 degrees advanced, zero, or 4 degrees retarted.
In the first photo, you can just see the circle on the crank sprocket aligning with the dot on the cam sprocket. But you can also see the keyway on the woodruff key that has a small circle (0 advance) on it, and the keyway at about the 9 o'clock position has a little triangle (4 degrees advanced) on it, with it's corresponding triangle mark at about the 8 o'clock position. The final photo shows the square keyway (4 degrees retard), but you can't really see it's square near a tooth.
Well the heavy lifting is now over, and if I get ambitious I'll pop off the valve covers tomorrow, back off the rocker arms, pull the pushrods and lifters. I've already got a box punched with 16 holes to keep the pushrods in their appropriate place. I've also got a couple egg crates lined up to keep the lifters in order, however it's unlikely they'll ever get used again.
And incase any of you wondered, yes I remembered to pull off the fuel pump so it's pushrod drops down allowing the cam to slide out.
And I have also been tempted to put in the Crane Cam I ran in this engine in the early 80's. I'm sure it's in my garage, however it may have gotten tossed during a purge about 5 years ago. I'm sure I have it's cam card here somewhere, but I remember it had .488 & .508 valve lift.
I mustered up some ambition today and got past the halfway point.
Valve covers off and pushrods out. The rocker arms just need to be loosened off and tipped aside to pull out the pushrods. I used to use a shoebox to keep the pushrods sorted, this worked just as well. You can't really see it, but the box is labelled front and back.
Lifters out: Pulling lifters out of a 30,000 mile engine that has had regular oil changes and never winter driven was a dream. Certainly a lot easier than on a 100,000 mile engine that hasn't lived a pampered life.
And a trick I saw in Hot Rod magazine about 40 years ago. Use a spare tire hold-town bolt to start pulling the cam out. Once the cam is part way out the bolt can be removed. It can also be used when installing a new cam.
Where'd the cam go?
New cam, lifters & push rods installed, and a bottle of engine break-in oil additive poured over the cam & lifters. Push rods are just in place, will set the valves at a later date. Stay tuned.
Well this is turning out to be the worlds longest cam change. I just don't have the get up and go that I had in my younger days. I set the valves a couple nights ago, and today I put the timing cover / harmonic balancer back on, the valve covers & new fuel pump back on. Tomorrow is the intake and the rest of the stuff. With any luck, I'll fire it up tomorrow afternoon.
However, I learned something when setting the valves. I always thought when the cam & crank dots were dot to dot (as seen in the photo below) that meant the #1 cylinder was at TDC on the compression stoke, ready to fire. That is incorrect.
When the marks are dot to dot, it's actually the #6 cylinder's compression stoke ready to fire. Yes, both #1 & #6 pistons are at TDC (as the firing order is 1-8-4-3-6-5-7-2), but it's really just the start of the #1 cylinder's 4 strokes of intake, compression, power & exhaust. So, now that I've got it mostly back together, I've turned the engine over so both the crank & cam sprocket dots are at 12 o'clock, and once the intake is on I'll drop the distributor in with the rotor pointing at #1 on the cap. Then it'll be ready to fire.
Nice work mate! Cool trick with the spare wheel hold down! Really enjoy a job with pictures.
Was reading a thread on a chev big block performance facebook page about the timing marks. I personally never have given much thought to what the marks on the sprockets means crank position wise and what stroke it was on for what cylinder. No matter what engine I have worked on I have aligned the marks as required the rotated the engine once together while watching the rockers on 1 for compression stroke, aligning the proven TDC mark and dropped in the dizzy.
I am changing my diff out and installing a posi and new gearset. I was considering giving it a crack myself. Watched a hagerty video on doing the job which was quite comprehensive and filled in some gaps in my knowledge. Wouldnt mind doing a post on that.
keen to see the next steps and how it runs!
-- Edited by koolconvertible on Sunday 14th of June 2020 04:31:27 AM
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cutting a roof off a four door is NOT a convertible.....
65 Parisienne convertible.one of 49 built for RHD export market,402BBC, T400, 2500 stally, posi rear, upgraded brakes with front discs, FUEL FAST efi custom built by me.
No matter what engine I have worked on I have aligned the marks as required the rotated the engine once together while watching the rockers on 1 for compression stroke, aligning the proven TDC mark and dropped in the dizzy.
Same! I never knew the marks on the gears were not together on #1.
I have always just watched the intake valve close, then brought the mark on the balancer up to the marks on the timing tab. That way you know for sure you aren't 180* out on the distributor. If the engine is out of the car you can't install the distributor ahead of time if the transmission is an automatic because it gets screwed up when you spin it to install the torque converter bolts later on anyway. I never install the distributor before putting in the engine because it just seems to get in the way. Once it's dropped in, set it on #1, drop in the distributor and Bob's your uncle!
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
I filled the coolant the other night with a 50/50 mix of Prestone concentrate and distilled water. I had a very small leak where the bypass hose goes onto the intake manifold, so tightened that clamp a bit more. Today I was planning on firing it up, but saw a very small leak from the thermostat housing, and the housing gasket was wet. I drained the system, and undid the thermostat housing, keeping the upper rad hose connected. I scraped off the gasket from the housing, and cleaned up the intake a bit. To be on the safe side, I took a small metal bar and wrapped some 220 grit sand paper around it. I used that to clean up the manifold side of the outlet a bit, it should make a difference. I remember doing the same thing on the 454 Laurentian.
I checked the orientation of the oil pump rod, and I used my specialty tool to prime the oil pump. I meant to post a photo of me laying on the engine working the cordless drill spinning the oil pump clockwise, but missed that photo opportunity. I then used a long screwdriver to put the oil pump rod back to the same orientation as seen before, so the distributor would drop down on it perfectly. This is where some pre-work comes in handy: Before pulling the distributor, I ensured I was on #1 TDC, then put some tape marks on the inner fender and battery where the rotor & vacuum advance were pointed. (the tape can be seen in previous photo's, one on the heater hose, and one on the battery). As the distributor shaft and rotor turns clockwise about 45 degrees as it meshes with the camshaft, I take that in mind before dropping it in. A little jiggling and distributor dropped onto the oil pump rod, and the rotor was pointing at my tape mark. I just turned the distributor housing so the vacuum advance was pointed at my tape mark, and tightened down the distributor enough that it can still be turned by hand.
I hooked up a timing light, poured about an ounce of fuel down the carb throat, and voila, she fired up right away. It stalled, but fired up right away again as the fuel pump pulled fuel from the tank and into the carb.
With the engine running at about 2000 RPM as recommended in the cam sheet, I spotted 2 fuel leaks:
1. Where the rigid line came out of the fuel pump, this was solved by giving a bit more of a turn with a 5/8" flare nut wrench.
2. Where the return hose connects to the return line back to the tank. I fiddled with it a bit, but it was too much to do with the engine running, so I shut the engine down. I pulled off the hose, saw the end was cracked a bit, cut off about 3/4", used a new clamp and put the hose back on. Fired up the engine and problem solved.
After running at high RPM for about 20 minutes, I figured that was enough. I cranked the idle down, then used the timing light to adjust the timing and put the idle down to about where it should be. I had to retard the timing from where the distributor was dropped in, but that's ok. I then tightened down the distributor.
A road test showed my manifold vacuum is significantly better, and a couple hits of the brake pedal made the front tires lock up, so looks like the goal of improved vacuum has been met. The engine doesn't have the power it had before, but there's still plenty there.
Oil change tomorrow to remove the cam break in additives.
'64 Parisienne CS "barn find" - last on the road in '86 ... Owner Protection Plan booklet, original paint, original near-mint aqua interior, original aqua GM floor mats, original 283, factory posi, and original rust.
