Guys that are running 127600 cams or locked out VCT

Those of you running bigger cams, are you running phaser limiters or lockouts? I'm thinking about just locking the phasers fully advanced and disabling the retard in the tune.

Just looking for input from others that have run bigger cams in both limited and or locked out configuration.

Thanks

What cams are you running and what is the intake center line? Phaser function seems to be more dependent on the valve springs than the cams.

People do it both ways. If you lock them out it's a good idea to have some retard so you don't run out of air in the higher rpms. Or, have cams ground with the icl around 108-110 depending on the cam.

Hi Bruce. Looking at Comp 127600 cams (http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=981&sb=0).

102° ICL using the 26125-24 springs. I can certainly degree them but comp tech support has no ideas what I'm trying to do so far in my conversations with them. I don't want to run the VCT (or at least I'd like to try running w/o the VCT) and they don't seem to understand what that means.

edit:

Is there such a thing as adjustable cam gears or crank gears for the 3V motors? I've got plenty of experience with pushrod motors but the OHV stuff is a little new to me.

csracing said:

Hi Bruce. Looking at Comp 127600 cams (http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=981&sb=0).

102° ICL using the 26125-24 springs. I can certainly degree them but comp tech support has no ideas what I'm trying to do so far in my conversations with them. I don't want to run the VCT (or at least I'd like to try running w/o the VCT) and they don't seem to understand what that means.

edit:

Is there such a thing as adjustable cam gears or crank gears for the 3V motors? I've got plenty of experience with pushrod motors but the OHV stuff is a little new to me.

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Yes, TFS has 2v crank gears that work with the 3v. I'd retard them 6* locked out. A 108 icl seems to work pretty well with the spr comp cams. I have what are basically 127500 cams with a 108 icl locked out and am very happy with them.

perfect. That's what I was looking for. Thanks for the info Bruce. I'll do some more research before asking more questions.

regards.

I have the Comp 127500 and locked them out, I can tell you I should have listened to Bruce about getting adjustable crank gears. I def. lost power up top due to no retardation.

Get the Livernois 10°degree limiter, with some trick on the vct tuning you can have a better curve and no issues.

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I am going with 127550 cams with my build and have Livernois lockouts and TFS adjustable crank gears to retard the cams 6 degrees for ~108 centerline. Are you saying that with Livernois 10°degree limiters I can keep VCT?

Will locked out be more reliable that keeping VCT? I may stick with reliable in exchange giving up VCT.

lito said:

Get the Livernois 10°degree limiter, with some trick on the vct tuning you can have a better curve and no issues.

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My custom Comp cams are basically the 127500 specs and I am running the Livernois limiters with them. I am very happy with the way these perform. I also have the Livernois springs and they are compatible with the limiters. If you have the Comp 26125 springs, I think you will need lockouts. I don't think the VCT can handle the high rate springs.

wht67 said:

I am going with 127550 cams with my build and have Livernois lockouts and TFS adjustable crank gears to retard the cams 6 degrees for ~108 centerline. Are you saying that with Livernois 10°degree limiters I can keep VCT?

Will locked out be more reliable that keeping VCT? I may stick with reliable in exchange giving up VCT.

Click to expand...

You can keep VCT with any kind of limiters, now, a few details and compromises.

The idea of limiters is to avoid PTV contact, basically, if you dont do it and you lose control (as you mostly will with certain cams and aftermarket valve springs) they go full retard and depending on stroke, piston design, etv, kaput.

So, the main idea of limiters are just that keep VCT with a safety net.

Depending on what combo you have one option usually works better than other, for a boosted app with strong springs/hot cams I would suggest locking and degreeing them with some retard, for NA, never locking them, NA horses are hard to come by and having the VCT helps, with strong springs/hot cam the short range limiters are good, help to have a broader curve.

Great info Lito. I've only found the 20 degree limiters from Livernois though..

http://www.livernoismotorsports.com/products/Ford-4.6{47}5.4L-3%2dValve-Cam-Phaser-Limiter-Kit.html

Call them, I just bought some a couple of weeks ago.

And BTW, why 10? because at that level you have zero VCT control and 20 degrees retard is too much, the system will work as noVCT-allVCT switch, keep it full advance all the time until you meet the conditions to go full retard and switch, with 20, that is way too much.

Fair enough. Thanks again Lito.

We recommend the limiters for a car with a blower or upgraded valve springs. If you have both we recommend the lockouts. Make sure you consult with your tuner as they may prefer one method or the other even out of application.

wht67 said:

I am going with 127550 cams with my build and have Livernois lockouts and TFS adjustable crank gears to retard the cams 6 degrees for ~108 centerline. Are you saying that with Livernois 10°degree limiters I can keep VCT?

Will locked out be more reliable that keeping VCT? I may stick with reliable in exchange giving up VCT.

Click to expand...

Good info here for sure, when I do heads I am going to be swapping out my lockouts for those limiters along with the valve springs.

Why would you need limiters with just a supercharger and a stock valvetrain?

Boost pressure can affect how the valvetrain works, so for any higher than the typical boosted application for stock longblock should consider springs and limiters, even for the stock cams.

I remember discussing this once before now, just not sure where the cross over point is where springs and limiters are required. Probably fairly high boost pressure. There's endless arguing on other forums about it, with people talking about boost pressure vs. valve area. I hopped on the school of thought where it's not that simple. There were anecdotal examples of people running high teens boost with stock valvetrain. There were others where the engine was nosing over at high rpm and a valve spring swap netted 40 or more horsepower.

I might just leave things alone, log the phaser operation, and address the "problem" as required. I'd really rather use the stock valve springs.

Good info. I have the heavy PAC springs on my heads. I will stick with lockouts & retard the 127550s 6 degrees with TFS adjustable gears.

wht67 said:

Good info. I have the heavy PAC springs on my heads. I will stick with lockouts & retard the 127550s 6 degrees with TFS adjustable gears.

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Still debating if I want to go with the TFS gears myself...