Thread: 350 crank

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well as many of you might know from all my stupid posts, but i have a 350 with a 327 crank in it but it still has the 350 top end in it, i have been told this was done to get more hp at higher rpms, but all it seems to do for me is suck through my gas faster than my buddies 400 hp engine and it seems to hate speeds over 50 or it will blow up, but i have been thinking about putting a 350 crank back in it, but i have been wondering if i will have to get new pistons, will i need to get shorter ones or not, they are nothing special, just .060 over forged steel, aside from that i don't know anything about them, but i don't think i would need new ones.

IF i am reading this right you say you are running a 327 crank with 350 pistons ???

A 350 crank has a stroke of 3.48"
A 327 crank has a stroke of 3.25"

The standard rod length of these 2 strokes is 5.7"

So therefor the pin height in a 350 piston is higher in the piston than a 327 by.230".

First thing I would do is do a compression check, see how many psi reads on the guage.

>A 350 crank has a stroke of 3.48"
>A 327 crank has a stroke of 3.25"
>The standard rod length of these 2 strokes is 5.7"
>So therefor the pin height in a 350 piston is higher in the piston than a 327 >by.230".

Your point is well made from a technical perspective. However, the change in pin height would be equal to the change in crank throw offset, which is equal to half the stroke increase, thus it would be half of .230" rather than .230". Enough, as you point out, to reduce compression considerably.

Bob

Your point is well made from a technical perspective. However, the change in pin height would be equal to the change in crank throw offset, which is equal to half the stroke increase, thus it would be half of .230" rather than .230". Enough, as you point out, to reduce compression considerably.

Bob[/QUOTE

whoops forgot about that

as far as i know it has 350 rods on it,


so can i do it or not

see i am planning to change the crank all by itself, by just taking the engine out and leaving all the pistons in, anyone ever do this, what are some good ideas for getting all the pistons on the crank and keeping the timing gears lined up and things like that, remember i am most likey doing this myself

Originally Posted by Nineftfreak

see i am planning to change the crank all by itself, by just taking the engine out and leaving all the pistons in, anyone ever do this, what are some good ideas for getting all the pistons on the crank and keeping the timing gears lined up and things like that, remember i am most likey doing this myself

Just a question, are you planning to pull the cylinder heads, so that you can see if the pistons are down in the bore with the 327 crank that is in it ? Or are you just going to flip the motor upside down pull the sump and front accesories off, out with the crank and put in the 350 crank. with a whole forest of big end bolts poking up to guide onto the journals ?

Just asking

i was just gonna swap cranks without removing the heads

Okay.......... 2 points, You are going to have all the big end caps off your rods, dont mix them up, so this is going to be fun keeping track of where all 8 main caps go on which rod.

Then you have all 16 exposed rod bolts to control so when you put your crank in youwant to make sure that the exposed thread of the bolts dont scour a rod journal.

Added all up your chances of your motor going nunga,nunga, rrrrrrattleBANG are pretty high.

I dont like using this method on V design engines because there is to much to keep track of. On straights like 4's and 6's it is not to bad because the installation is easier

my rods and caps are numbered so that won't be a problem, the only real problem i have is getting the rods on the crank without scratching it all to hell