running a 351 cam in a 302??

[Hal9000]

Small point but I think that you guys might be talking about two different things... Dual pattern cams and dual grind cams...

Dual pattern: Different profile on intake and exhaust lobes to adjust for breathing needs of the engine.

Dual grind or dual profile(Like the Lunati voodoo series): Different profile on the opening side and closing side of the cam lobe. the idea is to open quickly and set down slowly to improve the amount of valve-open time and reduce valve float.

If I'm wrong and you're actually talking about the same thing then please feel free to ignore me.

[broncnaz]

I'd never ignore you.
They are the same things in a sense.
dual pattern is different durations for the intake and exhuast. ie 270/274 duration Single pattern cams are same duration for both intake and exhuast ie 270/270
What your talking about is more related to lobe shape and while it does/can effect overall duration its more suited to roller cams which can stand the effects of a fast closing/opening ramp. Its also the goal in flat tappet cams but the lifters can only rise so fast before wear becomes a issue. And yes it can also be used for both dual and single pattern cams. But still dual profile, dual patten, dual grind name it what you will is all baiscally the same thing.

[Hal9000]

Only reason I brought it up was the mention of the Lunati Voodoo cams. If I'm not mistaken, their big claim to fame was that the profile of the trailing (closing) side of the lobe has greater duration than the opening side. They might be dual pattern as well depending on the application though.

[ADNICK]

Yea I should have put "dual grind" in quotes, because it is grinding two separate profiles.... Int/Exh dur something like 213/219 and lift 483/489

On the dyno the only place the "RV" won on torque was under the under 1200 -2100 rpm--depending on cam and as long as one did not get too crazy with lift and duration....

Lunati is not the only one many others offer them, I only mentioned Lunati because they provided the cams used in the dyno test....Racing Head Service provided the heads....


Later,
Nick

[Miker]

Thank guys, I appreciate all the insight and pearls of wisdom. Here is the reason why I asked in the first place. The 351 rebuild might come in stages, that is the 302 in the '69 I'm getting is still fairly strong but I COULD put the new cam in the 302 until I was ready to pull it, then just pull the 351 cam and lifters, keep lifters in order, new cam bearings in the 351 and I could "in theory" get two uses out of it. So, having said that, what about this comp cam for both a 302 and 351
Comp. Cam # CL35-238
Advertised duration 262/270
Lift .493/.500
I can give other numbers if it helps you understand what I'm looking at.
I'm trying to get away with not purchasing two camshaft within a year,,,,
Thanks!
Mike

[BRONCO26]

i have always ran a 351 cam in my 302 and i have also put a 351 cam in a 289 also it slids right in perfect just change to 351 firing order and fire it up.it does have a more desireable firing order and is easier on the crank and rods.

[broncnaz]

In theory and most times you can get away with reusing the camshaft and lifters although I would recommend installing new lifters in the new block. But really if you dont want to buy 2 cams dont bother installing one in the 302 just save it for the 351. Now if it was a roller tappet cam then by all means reuse would not be a issue.
One other route is to buy a cheap house cam from summit racing or similar company they might have one real similar or even with the exact specs as the comp cam you want and install that in your 302 they are cheap.
You may also want to find out if stock valve springs will work with the cam you want to install. Sometimes they require heavier springs.

[Wyflyer]

My Bronco has an original 302. I bought and installed a cam and lifter for a 351 lightning pickup(94 model I think?). I can't say there was a noticeable performance increase, but it will allow me to install the EFI and wring out all the gremlins, then someday lift off the EFI and swap in the 351 block and I won't have to do an engine swap and EFI install at the same time.

[matts70]

Had the same experience as ohpoo2--bought a Bronco with a 302 and 351 cam and didn't know it. Long time ago, I decided to de-grease the engine, but didn't mark the plug wires before removing them. No problem, just find a 302 firing order and connect the dots. Not exactly. It created serious aggravation, lots of time, and plenty of money before the local repair shop even figured it out. Oops.

Had an engine rebuilt and kept the 351 cam. I don't know if the performance is any better--I highly doubt it. After all these years, I'm seriously contemplating a switch to an Edelbrock camshaft, Performer intake manifold, and carb.

Lesson to learn: write down the 351 firing order somewhere very, very obvious as a reference just in case!

[HoosierDaddy]

Originally Posted by Wyflyer

My Bronco has an original 302. I bought and installed a cam and lifter for a 351 lightning pickup(94 model I think?). I can't say there was a noticeable performance increase, but it will allow me to install the EFI and wring out all the gremlins, then someday lift off the EFI and swap in the 351 block and I won't have to do an engine swap and EFI install at the same time.

Good idea to work out the EFI issues on a known motor , but having the old 302 cam in there is pretty much a "non-issue". Mine runs pretty dang well that way , a hell of alot better than I could ever get it with a carb. From what I understand , changing to the HO firing order will just make it idle even smoother than it does now.

[Oatmeal]

Originally Posted by GOODOLEBOY84

i read somewhere one time that the 351 cam was actually better for the 302, it supposedly puts less stress on the crankshaft and main bearing, its suppose to make for more even pressure on the crank from front to back, dont quote me on this i just read that, also thats supposedly why for went to the 351 firing order with the 5.0 ho

I too, have heard that---------Hans

[DirtDonk]

I would think it would be a good thing too. I've heard the same, or similar things to what you guys are saying.
From what I remember, the original reason for the 351 firing order was that the Ford engineers detected just the slightest harmonic vibrations, that were effecting main bearing (and maybe rod bearings too?) life in the region of cylinders 7 and 8.
Either the double-hit of the consecutive power strokes on rod journals next to the same main journal of the crank, especially towards the rear of the engine, or maybe even possible plug wire inductance issues with adjacent cylinders (7 and 8) firing one after the other were the cause. Either way, they took care of it by simply swapping the pairs of 5/4 and 3/7.
Seems the vibration was more apparent, and more theoretically detrimental to parts, with the longer stroke of the 351W.

It was about that same time too though, that the 400 was under development (model year '70 release, I think?), so maybe they detected the same thing in the even longer stroked 400? Since it uses the same firing order as the 351W, it would make sense.
The 400 was slated for the big heavy cars and trucks, as a heavy load torque motor, so mabye it became more important still to reduce that bearing wear.
Lotta maybes in those paragraphs!

There didn't originally seem to be any real issues over the years on the 260's, nor the 289's, but why they didn't just change the 302 at the same time, I have no idea. Seems to me that development was taking place at about the same time so they could easily have made the running change I would think.
Oh well, lots of goings-on in a big corporation like Ford. Lots of committees that don't talk to each other perhaps?

And the way I understand the reason they finally changed in the 302, was that, as rpm and performance levels increased in the 302's in the '80's, it was decided to adopt the 351's firing order for the same potential reasons. To reduce whatever dynamic issues had been more apparent in the longer stroked (higher tourque?) engines.
Maybe those committees just finally started talking to each other and asking questions?
Or maybe, as computers were taking over all ignition functions, some programmer somewhere said, "Hey, what's up with the two different firing orders?" so they changed finally.

About that same time ('69 or so) they were designing the 400, which was a very long stroke by Ford standards, and it got the same 351 firing order
I think the 351W was a '69 model introduction and the 400 was a '70? So maybe development overlapped and testing showed it even more apparent on the longer stroked 400.
Even more maybes! In the soon-to-be-immortal words of the Mythbusters though, it all seems "Plausible".

Paul

[Miker]

Great insights and comments all around,,, so,,, at the end of the day, do I leave my computer to go get a 351 cam for my 302 or leave alone??

[Wyflyer]

Originally Posted by Miker

Great insights and comments all around,,, so,,, at the end of the day, do I leave my computer to go get a 351 cam for my 302 or leave alone??

Are you ever going to EFI it?