Rocker ratio and hot cam

[cbr600rx7]

I have been on the phone with delta cams And want to pull the tigger on a mild re grind however we have hit a little confusion.

This has been my understanding:

Pre 88 Lima motors have a flat tapet cam with 1.5 rocker ratios.
89-94 rangers use roller rockets with 1.64 rocker ratios
95+ rangers use roller rockets with 1.86 rocker ratios.

However the rep at delta said he wasn't aware of any roller rocker ratio changes and was under the impression all rangers used the same rocker ratios. A 0.22 difference in ratio when multiplied by the cams lift can be very significant so if some one with experience and jump in here that would be great .

 

[cbr600rx7]

Any body?

 

[Mark_88]

Sorry, no experience with those numbers or engine builds in that detail. I took mine to a shop and they installed what they called a "mild racing cam" and it worked great.

Someone else might know this specifically but did you check the 2.3 specifications at the top of this page? There is a sticky with all kinds of specs of all the years and variations this engine was built with...

http://www.therangerstation.com/forums/showthread.php?t=9

You will also find a few names of members in there that have contributed over the years and they probably have discussed this in some earlier posts so a search might show up faster than a direct answer...

 

[Mightyfordranger]

Just a quick google here brought up this page http://www.route66hotrodhigh.com/2300Cams.html shoukd help shows stock cam specs and ratios

 

[Mark_88]

Just a quick google here brought up this page http://www.route66hotrodhigh.com/2300Cams.html shoukd help shows stock cam specs and ratios

Excellent find...

I actually have or had that website bookmarked but forgot about it until I checked your link...I remember someone on here posted it...

 

[cbr600rx7]

Hold the phone on that one. Not trying to knock the guy but some of his claims are a little out there. He likes to throw around HP numbers but has no real evidence to back it up. A perfect example of this is when he is talking about swapping out stock injectors that he claims are 14 pounds for 19 pound yellow tops with no tuning and says he gets better MPG and gained 10hp.

So here is just one of my rants on that sight.
Now before any one gets the axes and pitchforks out here me out. I have done a 19lb ford injector swap in a 4.0 with renix style ignition to get better performance. The truck started smoother and seemed to be more responsive. Most of the advantage was from the 4 hole tip vs he single hole I would expect and those motors also ran very lean from the factory. However here is the catch. When you compare the 4.0 renix injectors to the 19lb ford injectors at 44 psi they flow right around 18 pounds. I don't have the numbers in front of me but the flow rate was only like 3% less then the ford 19s. This is not the case when going from a claimed 14 pound stock injectors to a 19 pound injector and I would expect the motor to run terribly rich especially with a healthy pump or in a 98+ truck that has a even higher fuel pressure. I am sure with tuning you could run a 19 pound injector on a 2.3 especially if it was boosted or well bolted however I don't know if I would do it on a bone stock truck. Also his 10hp power gain seems a little ambitious for a motor that only puts down around 90hp at the wheels stock. Latter he talks about drilling into the MAF and other things that just seem like a bad idea or cheap solutions instead of proper tuning. In some of his other posts gen talks about Rich codes and some other issues he had with this set up. I think the guy is out to help other owners but I also know delta cams deals a lot with 2.3 engines and I would think they would know.

 

[Mightyfordranger]

Well not sharpening my axe on ya here but u asked for info cause deltas #s seemed off. I looked and posted what i found.but i will agree with your statements about the injectors and etc you make a good point there. But ill look and see where he got his info from if there is a sources page and get back to ya

 

[cbr600rx7]

Any one. I talked to them again today and they claim all ranger roller cams came with 1.8 rockers.

 

[tomw]

Given the way the geometry is set up, I'm not sure how you can change the ratio.

The only thing I can figure is you move the contact spot where the roller or the 'pad' touch the cam lobe. To increase, you'd move the contact towards the support lifter, but how can that be done when the cam lobe is staying in one place? Normal rocker arms, you can lengthen the arm, but you get an increase in the 'wipe' across the valve stem tip, so roller tips.
Is the cam follower moved in the roller cam followers?

tom

 

[55trucker]

Any body?

here's the cam spec from my '98 OEM manual on the 4cyl

the rocker arm is 1.86

see this link on a budget aftermarket cam & rocker arm specs

http://route66hotrodhigh.com/2300Cams.html

 

[cbr600rx7]

That claims that 89-94 rangers had 1.64 rocker ratios. However delta cams is saying that all ranger roller cams are 1.86.

 

[55trucker]

I'm inclined to take Eugene Blanchard & Allan Slocum's info as being correct, did you click on his link going to Merkuerenclopedia.com?


some good information in there on the various cams available, OEM & aftermarket performance & their profiles

 

[cbr600rx7]

So I called crower cams today and the tech said he was only aware of 1.64 ratio rockers for the ranger roller heads....

 

[55trucker]

lol.....

but we know better than that, don't we.........

 

[cbr600rx7]

So both rock auto and ford list different part numbers for pre 97 and post 97 ranger roller rockers. Clearly there is a difference but the real question are they in fact different ratios?