so help me try to understand this, this cam is so hard to control because it has the same lift as a larger cam but with less duration causing the ramp up and down to be much more dramatic, correct?

 

yeah i think what we need is a detailed parts list for all the valvetrain parts including the valves, retainers, locks, rockers and pushrods. i have asked for this before but never got a response

i have a feeling they at least need to be checked by someone other than who has already checked them

 

I don't think thats where the problem is.....

a detailed list wont help...... you can list things off all day long. everymotor is going to be different. Its not like anything is set in stone.

IMO these guys need a milder camshaft, but If springs will fix it then fine. Go for it.....

Its not hard to check rocker tip sweep so anyone with basic knowledge can do it. I really don't see that as a problem. Other than anything being bent Its not a pushrod issue

 

Think of it like hitting a 4" speedbump at 5mph or 10mph, at 5mph it will likely be a smooth experiance, at 10mph you test the bumpstops and need your fillings checked.
Not an exact example but is a easy comparison about how the same "lift" at different speeds(rates) is harder to control.

 

He listed in another thread that his pushrods were 7.45". I think they can be .300" off if those are indeed what he has.

I know for a concrete measurement you need to get down to an actual length test but my "guess" is that he needs a 7.1" rather than a 7.2". That is in no way me giving him advice to go buy some 7.1"s and throw them in there expecting it to solve his issue.

Totally agree... I think the cam is harsh and could be replaced but I don't think you are connecting the two threads where he stated he has 7.45" pushrods.

 

That is the way I understand fast ramp as well. The ramps are closer to "vertical" or "parallel" for lack of a better term meaning the lifter accelerates and very rapidly.

I would guess that one of two things is happening.
1. The lifter is being launched off the opening ramp once at the top.
2. The lifter is once it stats to descend, is unable to maintain contact with the closing ramp.

I think its the later. The same lift cam with more duration would lessen the fast ramp issue to some extent I think. Someone correct me if I m wrong.

BTW my pushrod length is 7.000" with dead center rocker pattern on the top of the valve stem face with a moderate overall sweep.

 

Good analogy. At the rpms up top it's hard to keep the lifter 100% in contact with the cam lobe when the ramp is so sharp.

 

.300 too long it would push the tip right off the end of the valve, I don't see anyway it could be that far off. It has to be closer to his needs even if it is wrong. .100 or .150 too long would be very noticable

 

That's why everyone has asked him for a list. His builder says they are 7.45". I'd be more willing to believe 7.15" was written down but not readable. At any rate this cam .....

 

thank you, that does help me understand it much better

thats what i was thinking too, and why i have a similar cam, but with more duration, and therefor much less problems

thats why i wanted a exact parts list, as far as i can tell i have a similar setup but with 7.150 rods, i know every set up can be different but with milled heads and a smaller gasket i have a hard time understanding how he could possibly need a MUCH longer pushrod

 

but it is easy to make a mistake, from what i understand it is very difficult to measure a pushrod with hydrolic lifters, and if he did do the right thing and make a solid lifter out of a hydrolic in order to test maybe he did that wrong or just made a simple mistake, which is why i suggested he at least have someone else check them at least to be sure

 

If there are adequate springs for this cam I'd almost treat it as a solid roller and pressure test them every couple of weeks if it's a daily driver.

 

yeah from what i understand bret even tells people that this cam will wear out springs prematurely, but every couple weeks might be overkill

man this is an awsome thread with tons of information, one of the best i have seen in a long time

 

I have stock lifters in the car, the heads have been milled, The heads were milled .042, they have almost a .020 thinner than stock head gasket, valves are .050 longer, valve job sunk so that moves everything up even more, 2.00 and 1.60 are the valves, the pushrods are 8308-16 hi-tech 5/16" 7.450" oil restricting from Comp..... , the rockers are pro mags 1.6 rockers 7/16 stud, trick flow guide plates, Pac 1218's beehive springs, Comp cams 10 degree super locks, part #
part#611-16 standard locks 11/32" and of course the B-spec-b4 cam from Bauer racing. is that enough on the parts list or do you guys need more......

 

Listing parts won't tell anyone about your geometry. You have to check it yourself. Like others have said if your pushrods were .3" too long your rocker would be sitting on the retainer and you would have dropped a valve by now.