348 4" stroke query

[61BUBBLE348]

Got my 655 truck block back from machining, bore and hone, clean up the deck and fit cam bearings.
Have the crank in and number 1 piston and rod in checking for clearance etc. It appears that the rod bolt will interfere with the bottom of number 2 bore.
Scat crank and rods.
Do I get new rod bolts that have a lower profile or remove material from the bottom of the bore.

thanks in advance, if anyone has images of what they have done it would be greatly appreciated

cheers

 

[La Hot Rods]

I had to clearance the lower cylinder bores for rods when I installed the 427 crank in Toms 409 truck block.

 

[MRHP]

I had to make clearance at the oil pan rail for my 4 inch arm in my 409.

 

[Tooth]

If your rotating assembly has already been balanced I would clearance the block. Putting in lower-profile rod bolts would require you to rebalance.

 

[63 dream'n]

I took this picture off the website I believe it was of BSL 409’s block you can see at the bottom of the cylinders the relieving that took place

 

[303Radar]

For my 4" crank, the bottom of my cylinders were notched for clearance and the oil pan needed massaging as well in my 348/431.

 

[61BUBBLE348]

Many thanks guys, I thought this was the case after doing some searching, but wanted to confirm this. Wasn't sure if water went that far down.

Just for the curious, I am building this engine to go in my 38 F*%d Coupe, backed by a 700R, mild cam and 817 heads, single 4 barrel (Holley Sniper) looking for a mild revving stump puller.

 

[chevytaylor]

That'll be a cool build Grub

 

[cruzin]

I have a 4 inch Scat kit in my 348/440 with ”stroker rods” it was plenty of room in my block.

 

[1964SuperStocker]

I have a 4 inch Scat kit in my 348/440 with ”stroker rods” it was plenty of room in my block.

What rods are you using? I'm guessing that if you bought a kit that it is made to clear but wondering what they used to make that work.

 

[427John]

It will be dependent on the design of the rod,some rods whether they be thru bolt or capscrew type use a longer bolted area putting the bolt head or nut nearer the end of the rod.The longer bolted area usually provides a more stable clamping force making for a more perfectly round big end.If your application is a high rpm,high horsepower one dictating the strongest rod possible,I'd say clearancing is a small price to pay to gain that.If your build will be more like my finally underway build for low rpm torque a bolt with a shorter bolted area will probably be adequate and provide more clearance. Cruzin's picture above clearly shows the bolted area I speak of on either side of the parting line.Another variable that will affect the need for clearancing will be how far down the bottoms of the cylinders intrude into the crank swing area of the crankcase,but I can't imagine there being too terribly much variation there from block to block but maybe there is.

 

[Don Jacks]

Scat,like Eagle makes two budget level rod series that could be used here.The cheapest use the rod bolt design simular to the stock rod.The next step up uses the cap screw design and most of these are "stroker clearanced",but all must be checked.

 

[Michelangelo]

With a die grinder & decent carbide bit, it shouldn't take but a few minutes per cylinder. This is no big deal since you only need about .035" clearance.

 

[Carmine]

I had a 454 "4" stroke crank and 396 BB rods put in my 348 block at the machine shop. I know there was some internal grinding done on the block to have the proper clearances. I don't think it was alot and I'm not sure what exactly they did, but the motor does run nicely. It's in my '56 gasser wagon, Carmine.

 

[BRYAN FUGATE]

I had a 454 "4" stroke crank and 396 BB rods put in my 348 block at the machine shop. I know there was some internal grinding done on the block to have the proper clearances. I don't think it was alot and I'm not sure what exactly they did, but the motor does run nicely. It's in my '56 gasser wagon, Carmine.

Get that 56 gasser to the rock n race what are you waiting for

 

[Carmine]

Have to line up a trailer for it. The drag strip is about 1.5 hrs. from me. No way I'm driving it that distance. But, it would be interesting to see what it does with that "W" engine. Last year I did a video of some hole shots in the driveway. Have to have the wife help me with posting them. Kind of neat, Carmine.

 

[BRYAN FUGATE]

Have to line up a trailer for it. The drag strip is about 1.5 hrs. from me. No way I'm driving it that distance. But, it would be interesting to see what it does with that "W" engine. Last year I did a video of some hole shots in the driveway. Have to have the wife help me with posting them. Kind of neat, Carmine.

Get you a trailer and make it happen. Uhaul rents then if you can’t find one to borrow be great to have you