Is there a significant advantage to changing the firing order of a 289 and using the 351w firing order? I've heard of power increases by doing this and wanted to better understand. I have a '65 289 to build, thinking maybe 331 and wanted to research inexpensive power increases. I had initially planned the Comp Cams 280magnum with about 10.5 compression. Using Edelbrock Performer RPM, Holley 570cfm Street Avenger, and Pertronix Billet distributor. It's a 4-speed car with 3.25 gear.
289 with 351w firing order
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I don't think there is any power advantage. I think the 83 5.0 got changed because they threw a 351 boat cam in it. It used the 351 firing order after that. If there is any chance you will use a Ford sequential injection system you want the 351 firing order. I have a Lunati cam in my 289 and the VooDoo only had the 351 firing order. If you can afford it I would use retro hydraulic lifters or a 5.0 roller block.
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Actually my cam grinder, Cam Research, preferred the 289/early 302 firing order over the 351w firing order when he ground the cam for my 351w. Something about the harmonics of no. 4 and 8 cylinders firing sequentially on the rear crank journal. However, with the 289/early 302 firing order, the front two cylinders fire in a row, so go figure. I don't think it makes a pinch of sheet difference in performance or reliability to the common street car.
I saw an episode of Horse Power TV where they did the firing order switch on an SBC, with before and after dyno runs to measure the results. There was definite power increase in using what we would call the 351W firing order.
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years ago I recall ford saying it was to " revise main bearing loads.." the old SBF and SBC each has the same firing orders, they just number the cylinders differently..
correct on taking the load of the 2nd and 1st mains
best order is the old one with 8/2 swap and a internal balance crank
If you can get a flathead firing order camshaft, that's the best. 2/8 swap. 15486372.
Kaase uses it on a lot of big blocks, but I don't know of anyone using it on SBF. IIRC, it's the similar to an LS-1 firing order just numbered differently.
I asked Scott about it when I had my last cam ground, but he said its a waste. Looks to me like that particular order would work very well, however I am not THAT deep into firing order changes and their affect on crankshaft harmonics, intake pulse tuning and exhaust pulse tuning. I wish I knew a way to try it without having to spend $750 on a custom core camshaft for my 438".
Kaase uses it on a lot of big blocks, but I don't know of anyone using it on SBF. IIRC, it's the similar to an LS-1 firing order just numbered differently.
I asked Scott about it when I had my last cam ground, but he said its a waste. Looks to me like that particular order would work very well, however I am not THAT deep into firing order changes and their affect on crankshaft harmonics, intake pulse tuning and exhaust pulse tuning. I wish I knew a way to try it without having to spend $750 on a custom core camshaft for my 438".
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Ford changed to the 351W firing order on the 302 / 5.0 HO motors because of strength issues.
Around 78 Ford removed / thinned up material around the bores and removed about 8 or so lbs frome the main webs.
This caused some issues. Main web issue was that with the std 302 firing order no 1 main was highly stressed. By using the 351 firing order it reduced the stress on the front main brg.
For a while Ford used both firing orders depending on if it was a lopo or the HO motor.
Reducing metal in the motor was just a cost save
Around 78 Ford removed / thinned up material around the bores and removed about 8 or so lbs frome the main webs.
This caused some issues. Main web issue was that with the std 302 firing order no 1 main was highly stressed. By using the 351 firing order it reduced the stress on the front main brg.
For a while Ford used both firing orders depending on if it was a lopo or the HO motor.
Reducing metal in the motor was just a cost save
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Perhaps to gain fuel mileage as well?
you mean by the less block weight , yes for the mpg plus a few dollars in iron cost for the factory
no for the firing order
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If you build a 331, I might be interested in your 289 stuff.
And that placed the load on the rear main bearing. NVH was what I was told for reasoning to change. Said the HO/351 order was supposedly smoother. I ASSume there was more to it than that...I'm not an engineer, just another backyard engine builder with no money.
I can see where crankshaft harmonics could be in play. With the old order (1,5 firing 90° apart) the crank has more of a tendancy to "whip" or twist. With 4 & 8 firing at 90° apart, there is less twisting of the crankshaft. Of the 3 crankshaft failures I've personally had with SBF engines, 2 were broken behind the #4 main journal and both of them were old 302 firing order camshafts-whether that makes any difference or not. The other crank failure was the block's fault. Spit the mains out and with nothing to hold the crankshaft securely, eventually it failed. I should have quit running it when the oil pressure was down but figured it was ok as it did not fluctuate; just consistently low. That was a direct result of a main web being broken away from the block.
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I had a complete short block 289 that I could hardly give away a couple of years ago. I finally decided to pull the rods and pistons and took the block and crank to the recycler. It was all low mileage and had been totally gone through, hot tanked, magna-fluxed line bored and cylinder bored .030 over. Even the crank had been gone over. I did keep the pistons and rods and still have them.
They are Speed Pro forged aluminum flat tops with four small valve reliefs. I don't know what cc that took up. The rods were checked out and re-sized and they are still together. One piston has some scoring on the walls and I'm not sure if it should/could be re-used. The cylinder it came from (1 or 2, I recall) was a little lower in cranking compression and it started to burn a little oil but nothing crazy. I'd replace it if it were me.
I would take just about any offer (really) for the set and would throw in the original oil pan that came on the car too. It's been sitting on my garage floor for about 3 years and is time to go. Shipping might be the deal killer 'cause I'm not paying for that. I'm in SoCal so pick-up's an option for someone maybe. If you, or anybody you know wants this stuff PM me so I don't miss it.
John
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Huh?
I dont understand THAT statement.... Can some 'spainin be done?That said, WAAAYYYY back in the day when i first got my Mustang, during my young dumb days, the engine had been swapped and a windsor put in place of the Clev, and being a broke young guy did what i could with the windsor. (both 4v motors) At that time the 51 W wasnt cool, and had to make do with what few pieces were made and forget anything over a RV cam for em, so I used 289/351 cams, which caused some ppl some confusion as my 51W had the 289/302 firing order.... As can be seen in my signature I am back to the cleveland and still behind the times....
:bs:A little off topic but Oldfart, you're right on the money about the 351W. I can remember when if you had a 51W, unless you were talking to a guy with a 283 or a six, you kept your mouth shut as they were for grannies and family picnics. Back then, I knew a guy with a shop who had a 351C totally built, balanced and blueprinted ready to go except for intake and he still couldn't sell it for $800 so who would ever want a Windsor? How times have changed.
that problem was on a 292 with a 2x4 intake ..Huh?
That said, WAAAYYYY back in the day when i first got my Mustang, during my young dumb days, the engine had been swapped and a windsor put in place of the Clev, and being a broke young guy did what i could with the windsor. (both 4v motors) At that time the 51 W wasnt cool, and had to make do with what few pieces were made and forget anything over a RV cam for em, so I used 289/351 cams, which caused some ppl some confusion as my 51W had the 289/302 firing order.... As can be seen in my signature I am back to the cleveland and still behind the times....
what brand it was , I have know idea , when swap for the factory 2x4 intake it ran correct .
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