Bronco Forum - Full Size Ford Bronco Forum banner
21 - 25 of 25 Posts

·
Registered
95 5.8L MAF XLT, Hedman Shorties/MF SS Y & Muff, E4OD, Man hubs, KYB Quads, 31x10.5x15, 311K miles
Joined
·
1,683 Posts
Discussion Starter · #21 ·
If you're going to have to monkey with the programming for the injectors (provided you plan on exceeding the 260 hp mark), might as well go ahead and upgrade the ECM to something like PiMPXS..then you can run whatever cam you want within reason and keep the SD

Also, this particular use of a vacuum pump would be "experimental" i suppose, but they are used quite a bit in forced induction applications, plumbed into a reservoir then all the vacuum operated goodies like HVAC and Power brakes run off of it.

The first Gen Z-r1 corvettes from the 90's had a dual runner setup on their LT-5 DOHC engines, and when you put the engine in "Full" performance mode, this activated a small 12v vacuum pump that would open the secondaries under full throttle giving you all 405hp. I had one of these and that pump in particular is what made me think of the whole "auxillary vacuum pump" idea. 405 HP out of a naturally aspirated 350 engine in the early 90's wasn't too shabby.
BTW that manifold on the Vette I know about that as it came many years after my idea in College. My Senior Paper in 79/80 was going to be about a "Variable Runner Intake Manifold", but I stopped because of Political problems. There is the Variable Venturi Carburetor (Ford) way back when also. It got Really Deep the whole Idea/Concept. Just some Fun Facts from my past!!! Believe it or Not!!!
 

·
Premium Member
1986 Bronco Eddie Bauer 5.0 mostly stock
Joined
·
1,832 Posts
You want to "debate" and stick to "Facts" and the info supplied is that Rhodes very well MAY solve the problem I agree with your hypothesis, but the fact remains that nobody involved with this discussion so far, nor that i have seen has tested it, so its just as experimental as anything else mentioned. I don't want to be a guinea pig on this when there is already a proven solution in the form of computer friendly cam/lifters.
If someone was to try the rhodes lifters, they would have to do some major engine dissasembly, break in the new lifters to the cam, and hope that it works out for them...and if it does great, but if not...they got to go back in and buy a new cam setup, gaskets, engine oil, etc.
I get the spirit of the conversation, and it's truly an interesting idea, just a hard sell whenever theres already a solution for that particular problem...unless I'm missing something which is entirely possible.
I have read about the variable venturi carb, but one of the greatest pokes in the eye that i like is when Honda put their CVCC tech on an Impala in the 70's to prove there was a better way to lower emissions and make more power doing it. If you've never read this (you probably have) its very interesting.

 

·
Registered
95 5.8L MAF XLT, Hedman Shorties/MF SS Y & Muff, E4OD, Man hubs, KYB Quads, 31x10.5x15, 311K miles
Joined
·
1,683 Posts
Discussion Starter · #23 ·
@robbz28 they make Roller lifters also so no break-in necessary just remove old and drop-in new, then adjust and button up and go. Basically anyway...
I'll look into the attachment thanks I'm never too old to learn.
 

·
Man of endless projects
Joined
·
10,308 Posts
i understand what your trying to get at with these. and they may get good results on a carb setup to help it idle better with an aggressive cam. but i jsut think that the results are too unpredictable to attempt to fool a speed density EFI that has set parameters. this will go for low and high rpm range

my point with the variables was that when the engine is idiling and hot it might be fine. but when the engine is cold and idling it might not be leaking down enough to let it idle correctly. but also if your cam is still pretty mild, it might not work at all because it wont leak down enough. in the end you are taking a gamble on how well it would work. and i dont think anybody wants to be a guinea pig in testing your theory. especially when you can go with a something that they know will work and might just sacrifice alittle top end power.

because if you think about it and you attempt this by putting in these lifters and a more aggresive cam. if it does not work out that is alot of money wasted on. a roller cam is over 300$ that you will be swapping out. and if you put in a 'known-good' camshaft, do you really want to keep these lifters knowing you are loosing performance? yet alone the task of swapping the cam or lifters is really not that fun

also would you be doing this with stock heads and injectors? cause a cam will not really help that much with stock E7 heads. will it be an improvement? alittle. is it worth the experiment? thats up to you. i wouldnt even bother doing a cam swap with stock heads. too much of a pain for so little gain.

the 19lb injector will still be a limit for higher power if you do a head swap or something. yes people can raise fuel pressure but then you are still affecting the set parameters of the EFI. because it is now acting like a larger injector. but also the other specs of the injector are affected by higher pressure.
 

·
Forward Some Money
Joined
·
5,107 Posts
Not sure if it really adds to the conversation, but may be a bit of food for thought.....I ran a SD setup with a MAF cam shaft. I thought it was going to be the end of the world when I found out the builder installed the wrong cam. Figured that when I converted to MAF the engine would find incredible horsepower or behave differently. It did not.
 
21 - 25 of 25 Posts
Top