valvetrain and cam swap questions

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valvetrain and cam swap questions

September 20, 2013, 03:08:53 PM

I have my old mustang engine on the stand. It has been there 3-4yrs. It ran fine when I pulled it.

I want to take out the B cam and put in a stock HO cam.

Do I need to keep the valve stems and 1.7 RR in the same spots?

When I go to install them back, are the roller lifters bled down? How do I install the pedistal RR and tighten them correctly?? I havent installed them before, my buddy did it years ago, and we had some shims under some of them.

valvetrain and cam swap questions

Reply #1 – September 20, 2013, 07:24:26 PM

I've always done it following these instructions:

http://www.lincolnsonline.com/tech/00078.html

As I hand tighten the rocker bolt to take all the slack out I try for 1/2 to 3/4 turn till I reach my torque spec. Than add or remove shims as necessary. Not sure if it's the proper way but it always worked for me, there's a lot of threads on the corral about it and I recently read that using the balancer marks to find which valves to do is not the proper way either. So read up and find what works best for you.

valvetrain and cam swap questions

Reply #2 – September 21, 2013, 12:51:46 PM

By valve stems I'm guessing you mean pushrods? I've always heard that you should keep the same rockers/pedestals/pushrods together as they wear into each other. I did when I swapped heads on my engine. I think it applies more to stock rockers then roller rockers though. Roller lifters on the other hand can go back in any order as they don't wear into the cam.

As for setting pedestal rockers I've followed this guidline for a few years and it has worked great for me http://sbftech.com/index.php/topic,318.0.html

valvetrain and cam swap questions

Reply #3 – September 21, 2013, 02:22:56 PM

Thanks guys.

Yea, meant pushrods lol

Can I get accurate results torquing them down with the engine that has sat for many years??

valvetrain and cam swap questions

Reply #4 – September 21, 2013, 04:19:03 PM

Quote from: mcb82gt;422033

Thanks guys.

Can I get accurate results torquing them down with the engine that has sat for many years??

I would think so. After all when you assemble an engine the lifters aren't pumped up.

As for a cam unless you have a stock HO cam I would get something just a bit more aggressive. I'm running this cam in my set up with 1.6 roller rockers: http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1048&sb=2

This one has similar specs to the one I'm running and is designed for the 1.7 roller rockers you already have: http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1059&sb=2

valvetrain and cam swap questions

Reply #5 – September 21, 2013, 07:29:22 PM

I do have a stock HO cam laying there. I figured it would idle/drive better than the Bcam in there.

I have no idea what those cam specs mean. I want good idle/drivability. Not sure though how much Im leaving on the table with HO cam and Edelbrock performer heads????

valvetrain and cam swap questions

Reply #6 – September 21, 2013, 08:38:46 PM

My old tbird ran edelbrock heads, cobra intake, tfs-1 cam, t-5 with 373 tc rest and 24 lb injectors and the car ran great... Good power and good drivability.

valvetrain and cam swap questions

Reply #7 – September 22, 2013, 08:40:03 AM

Im just trying to keep it really cheap on this motor. Its an old roller motor I got years ago with about 100K on it. I ran it in my Mustang with the Edelbrock heads for years and another 30K miles. It is getting pretty tired.

It got ran pretty hard in that Mustang.

My long term plan is to run it in my Cougar as long as it holds together. While TRYING to save to rebuild it and maybe do a 331, possibly a custom cam at that time.

valvetrain and cam swap questions

Reply #8 – September 23, 2013, 12:20:52 AM

Ah now I get what you're doing. If you're putting in a better converter (2500+ stall) you could keep the B cam in the engine. Being that you're probably going to keep the stock torque converter in the transmission you're probably better off running the stock HO cam, especially since you already have it. I thought you were going to buy a stock HO cam, which I why I suggested the Comp pieces. Since you're more than likely going to rebuild the engine at some point I would wait till then and pick up a cam for the rebuilt engine.

You're going to want a better than stock intake on the engine when you swap it in. Your best cheap bet is an Explorer GT40 intake and a 65mm or 70mm throttle body. I would convert to MAF and run 24lb/hr injectors as well. You might be able to get by with a SD HO computer and 19lb/hr injectors but you won't get the most out of the engine.

valvetrain and cam swap questions

Reply #9 – September 24, 2013, 09:48:26 AM

Ive got the Explorer intake, I was goint to have Tmoss port it, but Im going to wait on that(money). Ive got the 24lb injectors and Mass air pieces. Got a C3W computer. Im unsure on 65 or 70mm TB..... any advice? Probably just pick up an Explorer piece and convert it, (again, money).

I figured on doing a torque converter, I just cant afford the PI piece currently. I was considering a DirtyDog converter. I am also planning on Dan at SilverFox doing a recalibrated valvebody for me.

Ive got the TC rear in, with 3.73 gears.

Im just wondering about idle quality with the Bcam and auto tranny. It was pretty lumpy in my Stang. Im unsure about converter stall, just thinking a little higher than stock 23-2400????? Want good driveability and "good" mileage.

valvetrain and cam swap questions

Reply #10 – September 24, 2013, 12:32:44 PM

keeping the rr on the same valve is perfered,, since they have mated to eachother assuming the valves and rr were new when installed.
to help mis match, and just install anywhere, use your 1500 or 2000 grit sand paper and buff out the wheels on the rr, that will make you kind feel better about not having to track all 16 spots.

to tighten, follow the firing order with #1 tdc,,
this will put you on the base circle of the cam lobe,, actually anywhere on the base circle from tdc to bdc is fine... just make sure the valves are closed.

next snug down the rocker arm until the bolt stops by hand.
next set your torque wrench to approx 20ft/lbs
next position your torque wrench to where the end points at 12 oclock,, as best you can.
now rotate the torque wrench and tighten to 20ft/lbs. you should not exceed more than 3/4'' turn

speaking to the lifters... there really is only way to bleed them down to make them coorperate with you during your rocker arm re-install.

initially i would drop in all your lifters , snug down your old or even new rockers (dont torque), then rotate the crank such that the now empty pushrods take on the oil that was trapped inside the lifter.

new liifters out of the box you can push in the cap a little and make all the internal parts move back and forth.
pumped up lifters trap the oil from the last engine cycle and should in my opinion be bled down before going on to properly torqing the roller rockers your going to end up with.

I reused a set of rollers but i took each one apart and removed all the debris that did not belong.
you would be amazed at how much stuff stays behind inside the lifter. the very very bottom area in the lifter body collects debris.
I sanded down the two moving round pump pieces and also cleaned out the side drilled hole,, also i cleaned out the bee bee / spring and cap area.

once you get the lifters bled down, you will see that the larger spring in the lifter is not conflicting the valve spring.

a stock lifter has approx .120'' of total travel for movment to carry the burden of pumping oil up.
to put this in perspective, that approx twice the distance as your spark plug gap... not really all that much you see.
when installed, your push rod needs to have available most of this travel distance.
on stock rockers you notice that will both valves closed, with some or little effort you can spin the push rod. ,,, thats because all the valve seats are uniformly cut to a specific depth into the heads thus all the valve stems are poking out at a uniform height.

if your valve seats were cut by hand individually, this changes the geometry of each individual valve but... you have the lifter to save the day because the lifter has .150'' travel. You start getting in trouble when the push rod is demaning too much depth into the lifter and so shims customized to each valve is calculated.

in my case, my son and i are still on the cuff of considering shims.... we are consuming about .030 on average of the lifter ,, that makes the push rods kinda tight when both valves are on the base circle.

several people here helped me get my head around this lash concept with roller rockers and really i cant see much difference in rollers vs non rollers considering the ratio is still constant at 1.7 from the factor or in roller form.
what i do know is that if valve seats have been re-cut or cleaned up, that could effect why you have shims on some valves and not others.

there are some vidios out there that basically say the following.........
-snug down the rocker only until you reach the point which the push rod starts to experience friction by spinning with your fingers.
-at that point you torque and if you exceed 1/2 to 3/4 of a full turn in order to reach your torque then you need to shim.
-----hopefully i bundled the whole process into the the above two sentences.

if you want pictures of the internals of broken down lifters, i can post them along with an increase oil lub mod.

valvetrain and cam swap questions

Reply #11 – September 24, 2013, 01:07:41 PM

Quote from: mcb82gt;422295

Ive got the Explorer intake, I was goint to have Tmoss port it, but Im going to wait on that(money). Ive got the 24lb injectors and Mass air pieces. Got a C3W computer. Im unsure on 65 or 70mm TB..... any advice? Probably just pick up an Explorer piece and convert it, (again, money).

I figured on doing a torque converter, I just cant afford the PI piece currently. I was considering a DirtyDog converter. I am also planning on Dan at SilverFox doing a recalibrated valvebody for me.

Ive got the TC rear in, with 3.73 gears.

Im just wondering about idle quality with the Bcam and auto tranny. It was pretty lumpy in my Stang. Im unsure about converter stall, just thinking a little higher than stock 23-2400????? Want good driveability and "good" mileage.

The Explorer GT40 intake should work fine with the heads. I’m running one with no issues. I would get the lower ported if you can as that’s the restriction. The lower on mine isn’t ported and I know it’s holding power production back a bit. The GT40 lower flows about 210-215 CFM (the upper flows around 250 CFM) stock. The Edelbrock Performer heads I have flow 245 CFM. With the intake flowing less than the heads the car is probably down ~20 or so HP. I’ll be sending off the spare GT40 lower I have in the garage to Tmoss over the winter to swap onto my car in the spring. The C3W computer should work fine with the 24lb injectors and a calibrated MAF. I’m running an A9P (basically the same thing, 5.0 HO auto trans MAF) with a 73mm C&L MAF with a 24lb calibration tube with no issues. As for the throttle body either a 65mm or 70mm will work. I had a 65mm and switched to a 70mm. The throttle response was better and the car went .5 MPH faster in the quarter so the larger TB may be worth ~5 hp. If you have a 65mm TB run it.

From what I’ve heard DirtyDog makes a good converter. Paring that with a SilverFox valvebody should really wake up the AOD in your car. With the 3.73 gears I would go with at least a 2500 stall converter, if not more. I thought a 2800 stall was going to be too much on the street when the guy who built my trans suggested it. Really it’s not. I drives just like a stock converter except it pulls stupid hard off the line when the throttle is mashed. Talk to the guys at DirtyDog and tell them what your combo is and how much the car weighs. They should be able to recommend a stall speed that will work with what you have. As a FYI my Thunderbird with every option except a sunroof and a full tank of gas weighs 3552lbs (with me at 152 its 3702lbs). These cars are heavier than Mustangs so they need more stall speed to get them moving off the line.

As for idle quality with the B303 yeah it’s going to be a bit choppy. Without a higher stall converter it will be a dog off the line. The computer would probably be happier with the stock HO cam. The stock HO cam would make more low end torque but with the right converter the B303 would be fine. “Good driveability” is a subjective term. The cam in my Thunderbird idles great with a bit of a lope but the stock HO cam in my Mark sounds smoother. They feel about the same at idle sitting in the car. The Thunderbird make much more low end torque, especially so with the PI converter. That is the key with any cam, even a stock one: upgrade the converter. It will make a hug difference and even make that B303 more tractable.