cam change @ firing order change

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3rdowner
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cam change @ firing order change

Post by 3rdowner »

Can you put an after market cam in an older 302 block and change the firing order from 15426378 to late model firing order?

ED
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craftsman
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Re: cam change @ firing order change

Post by craftsman »

Yes, just make sure you use flat tappet cam. To use roller you have to drill and tap for the spider plate that holds the lifters in place. Get it for the 5.0 h.o. then just change the plug wires around for the new firing order. :thup:
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Re: cam change @ firing order change

Post by rjewkes »

doesn't the crankshaft also decide your firing order?
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Vinniesempire
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Re: cam change @ firing order change

Post by Vinniesempire »

not always, think of the 4/7 swap on chevys.
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Ranchero50
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Re: cam change @ firing order change

Post by Ranchero50 »

You know, I've never read why the 351w had a different firing order. There has to be a reason. I wonder if it was a crank torque loading issue with the larger displacement? 4-8 only go to the flywheel, 1-5 torque all the way through the crank throws.

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Vinniesempire
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Re: cam change @ firing order change

Post by Vinniesempire »

the firing order change from the old 302 order to the 351 style for the 5.0s was for efi and NVH. the old order wreaked havoc on the knock sensors. i have no clue why 302s and 351s were differrent in the first place. i guess it might be because the 302 and smaller engines came out in i think 1960 and the 351 came out in 69.
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craftsman
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Re: cam change @ firing order change

Post by craftsman »

The 1983 5.0 ho were not efi and still had the 351 firing order.
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Vinniesempire
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Re: cam change @ firing order change

Post by Vinniesempire »

the change is also worth a couple horses depending on your combo. i know the 4-7 swap on chebbies can be worth up to 30 hp in a lot of cases, and sometimes it loses hp to. the 302 change over from old to new was during the development of the efi system for that engine.
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