Author Topic: Hesco Hi - Po camshaft info (Read 4813 times)

Beachbum · « **on:** April 14, 2006, 01:46:51 PM »

I ordered a Hesco RV0B4 camshaft and double roller timing chain and gear set from Hesco today and learned a few things while ordering it. I thought I would share what I learned, someone else might find it helpful. I talked to a guy named Benny or Denny, I'm unsure due to a bad telephone connection. Hesco recommends that valve springs be changed for this cam if you intend to run high RPM's, but they don't have to be, I chose not to change them. He also reommended the timing chain and gear set, this set is keyed in 3 different positions on the crank gear, advanced, straight up or retarded. He recommended to install it in the advanced position, this will give a good smooth idle and good vacuum at idle, to provide a good signal to the MAP sensor and prevent check engine light coming on etc. due to poor vacuum. He said this cam installed in this way will work very well with the fuel injection and should provide 20 to 25 extra ponies and increase torque sustantially from off idle to redline. I hope this info might help someone else who is cam shopping.

Jeffy · « **Reply #1 on:** April 14, 2006, 02:08:54 PM »

What's the cam profile and how much did it hurt the wallet?

Beachbum · « **Reply #2 on:** April 14, 2006, 02:41:04 PM »

Here is the published info on this cam, it is available on the HESCO website. Model # RV0B4, advertised duration 264, duration @ .050 = 214, lobe centers 110 degrees, lift .470. Cam and lifters = $239.00, double roller timing chain and gear set $149.00. I also purchased a valve cover gasket and timing gear cover gasket.

supryj4 · « **Reply #3 on:** April 14, 2006, 06:31:00 PM »

That is the same cam I purchased I am still waiting for my head to come back from the machinest I decided to go whit the springs you need to have the sping seats machiened for the hight of the new springs.Just for your Info his name is Bennie and he is very helpful with any questions I have had. Did he also tell you about setting your preload on your lifters he said it should be at 50 thousandths.

Beachbum · « **Reply #4 on:** April 14, 2006, 07:31:08 PM »

Did you also purchase the timing gear set to install your cam in the advanced position? I decided to stay with the stock springs mainly because I don't want the downtime waiting to get the head done, if I find out I need them then I can get it done. He didn't say anything about preloading the lifters, are you milling the head? If so maybe that's why he mentioned it to you, I don't believe the valves on the Jeep engine can be adjusted like a small block chevy, I'm not sure how they are preloaded. I'm going to look in my Chilton manual and see if I can find anything about it, if not the instructions that come with the cam will probably explain the procedure. Good luck !!!!!!!

supryj4 · « **Reply #5 on:** April 16, 2006, 08:28:41 AM »

Yes I did get the double roller timing set.Yes I am milling my head but very minimal only 3 or 4 thousandths or so just to flaten it out.The preload should be at 40 to 60 thousandths but he said 50 is ideal.Bennie also said that if you rotate the pushrod in between your fingers as you tighten down on your rocker until pushrod gets snug then you want 50 thousandths preload from that point. Bennie sent me shims whith my cam when I ordered it.I have three different heads so I was not worried about down time and when I finaly get the head back I will be installing the head, cam, timing chain set, and adjustable feul pressue regulator, then we will see wat kind of differance it makes.

yellowta · « **Reply #6 on:** April 16, 2006, 09:05:04 AM »

Quote from: "Beachbum"

I don't believe the valves on the Jeep engine can be adjusted like a small block chevy, I'm not sure how they are preloaded. I'm going to look in my Chilton manual and see if I can find anything about it, if not the instructions that come with the cam will probably explain the procedure. Good luck !!!!!!!

If you shorten the head .03 you have to raise the rocker arm .03 or you will be compressing the lifter .03 further. Or you could just put up the coin for pushrods that are .03 shorter

.03

Beachbum · « **Reply #7 on:** April 16, 2006, 02:41:03 PM »

If it turns out that I want to install the valve springs and mill the head I'll probably do like you did, get another head and have it done, then install it (trying to keep costs reasonable). I see from your previous post you are also installing an adjustable fuel pressere regulator, are you going to install different injectors also? I've been wondering if changing the injectors would benefit the new cam, I'm going to wait and see how the jeep runs before ordering more engine parts. I have 2 more expensive projects to get done that I really need to concentrate on before more engine work. They are a Banks or Borla header along with a completely new exhaust system, this needs to be done before more engine work as it should help the engine breathe considerably better and help determine if new injectors are needed. The second big or expensive project I need to do is install 4.88 gears, along with brakes front & rear, and anything else I find that needs attention while doing these jobs. I'll just keep throwing a little money at the thing until I get it where I want it.

supryj4 · « **Reply #8 on:** April 17, 2006, 02:45:30 PM »

I was told that I should not need bigger injectors so I will try it with out them and see how it runs.

wrangler387 · « **Reply #9 on:** April 17, 2006, 04:02:20 PM »

^ since you purchased an adjustable fuel pressure regulator you will be fine.

Beachbum · « **Reply #10 on:** April 17, 2006, 05:59:35 PM »

I've got to ask a dumb question guys, what difference will the adjustable fuel pressure regulator make? I'm assuming increasing the fuel pressure will also increase fuel delivery to the engine. I'm guessing that the injector is open for so long, and the more pressure it has the more fuel it will deliver to the engine due to the increase in pressure. Did the fuel pressure regulator also come from Hesco? I've noticed they sell 1 for the 4.0L but didn't see 1 for the 2.5L. Maybe they are interchangable.

wrangler387 · « **Reply #11 on:** April 18, 2006, 01:57:17 PM »

^ Kind've. Under cruise conditions the ecu constantly changes the duty cycle of the injectors to keep the motor running at a 14.7 air to fuel ratio. (hard to do with the little narrow band O2 sensors). Under WOT (wide open throttle) i'm not to sure what the jeep is set up to do. Some vehicles under WOT the ecu doesn't use the O2 sensor, instead the ecu injects a certain amount of fuel determined by the MAP sensor and RPM. This WOT is like you were talking about, it is a set injector duty cycle. I'm not positive the jeep is set-up like this but it might be.

supryj4 · « **Reply #12 on:** April 18, 2006, 08:23:26 PM »

Yes the fuel pressure regulator is from hesco.The box says its for a 91-95 4.0L and 91-99 2.5L.

Bounty Hunter · « **Reply #13 on:** April 29, 2006, 11:58:27 AM »

Why not go ahead and change the valve springs, it's relatively inexpensive and easy to do. I used Mopar performance springs #p5249464.

sharpxmen · « **Reply #14 on:** May 30, 2006, 12:00:39 AM »

Did you install your cam yet? Post an update when you do.

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Author Topic: Hesco Hi - Po camshaft info (Read 4813 times)

Beachbum

Beachbum

Beachbum

yellowta

Beachbum

wrangler387

Beachbum

wrangler387

sharpxmen