What do these engines rev too?

[WesB]

I installed a tach this last week on my B2. Last night was the first time I had driven it with the new tach installed (it's my toy, so I only drive it about once a week). I floored it to see what it revved to and at full throtle I shifted at 3800 rpms. That seems really low to me. Do these engines just not rev? Are they really that inefficient? I wanna switch over to a 302, but am kinda curious as to what these engines are capable of with some head work, cam, duraspark conv (which I haven't done), and better exhaust.

 

[igiveup]

Hello

I have seen my 2.8l with dura spark rev at 6000-8000 rpm on the tach. Cheap tach so it could be wrong. 4 low in first gear to the floor in 3 feet of mud.

igiveup

 

[Surrey]

Thats about the range my 1989 Bronco2 shifts at when Im on the throttle, just under 4000rpm.

 

[2813josh]

Hello

I have seen my 2.8l with dura spark rev at 6000-8000 rpm on the tach. Cheap tach so it could be wrong. 4 low in first gear to the floor in 3 feet of mud.

igiveup

8000RPM? Holy shit!

 

[Vanner1993]

I blew my 2.9 at 8000 haha. I don't plan to bring it up there anymore.

 

[Twister]

I have had mine at 4k - 4300 rpm because of a dying a4ld. Some have had it at 5k.

 

[JoshT]

I installed a tach this last week on my B2. Last night was the first time I had driven it with the new tach installed (it's my toy, so I only drive it about once a week). I floored it to see what it revved to and at full throtle I shifted at 3800 rpms. That seems really low to me. Do these engines just not rev? Are they really that inefficient? I wanna switch over to a 302, but am kinda curious as to what these engines are capable of with some head work, cam, duraspark conv (which I haven't done), and better exhaust.

What is it you are trying to ask about? Is it do these engines rev high? Are these engines efficient? Or do they make power? It is important to remember that not all engines make power at the same RPM.

Couldn't tell you what a stock 2.8L will max out on revs at, never been around a stock one. I know the one in my 84 listed in my sig would have no problems getting up there in RPM with over 160K on the odo (that's assuming it only rolled over once), but it had no tach at that time. Since the rebuild it has no problem hitting 5 or 6K, that's with a bad tuning on the vacuum secondary carb. Pretty sure it would do better with the double pumper sitting on the shelf waiting for a rebuild.

 

[dangerranger83]

I have had mine to 7,000 rpm without a load on it and with a load up to 6,000 rpm before i let off. Is there a need to go that high, not that I have found, not unless you plan on desert racing it or something needing high rpms.

 

[WesB]

Thanks to all for the info.
JoshT, I am just trying to figure this engine out. Shifting at 3800rpm with wide open throttle just seemed low to me. That tells me that the eingine isn't very effecient and shouldn't be revved very high. On the other hand, I'm still running the stock comp carb and it runs extrememly rich and that could be hurting my shifting points.

 

[Frank The Tank]

Your foot must be broken........ my truck shifts when i hit the clutch at any rpm I like.

Frank

 

[dangerranger83]

I shift mine at 3,000 rpm when Im really accelerating all the way up to 3rd gear. Also when I get to 3,000 rpm, I dont have to use the clutch (dont do that) to get up to 3rd gear.

 

[Surrey]

I think he is talking about an automatic tranny shifting...

 

[WesB]

yeah, I have a c5

 

[Mudhound]

Well, that certainly explains the "low" shift points then. On my 5sp BII, I hit 2nd at about 10-12 mph, and 3rd around 25, 4th around 60, pray REALLY quick, hit 5th and merge into the interstate traffic. No tach, just wait for the valves to make more noise than the exhaust does to tell me when to shift it. Most likely has ALOT to do with why the poor 2.8 doesn't run as good as it used to, along with the clutch not liking me much either.

 

[dangerranger83]

I would never put an auto behind mine, hate not have full control of what it does. If you wanna fix the problem, put a manual behind her.