Restarting my 348 project!!

[Tim]

Ok I’ll wait until the block is bored and decked to get what I need and make sure I get it right. I have 817 heads I’m getting from Dan and the 409 crank I already have from Tom, when everybody says “BBC “ I’m assuming it’s the 396/427/454 etc. ? The 6.135 rods are BBC and 6.09 are 409?

 

[Don Jacks]

Tim,Have the block bored and squared up,then do a mock up and measure the deck height.Once you determine that,then have the deck milled enough to get the piston to zero deck height.The stock 409 rod length is 6.09,the stock rod length for the big block is 6.135.The 6.385 rod is an aftermarket improvement,much like the 6.0 inch rod for a small block.The price for the 6.135 and the 6.385 is in most cases the same.The 817 head is a really good choice for what you're wanting to accomplish.The 409 length rod and the stock stroke 348 piston will give you a bit more compression,but the torque will be peaky.The longer rod,and the 7815 piston will have a bit less compression,is lighter,and has a broader torque curve,which is better suited in a street car for driving pleasure.

 

[Tim]

Here what I know for sure, 409 crank in a 348 block,bored 30 over, 817 heads,951 cam , 11-1 pistons to get what I want or close to 400 hp, I know the 348 rods won’t work, from what Don and Tom say the KB pn7815 Pistons with 6.385 BBC rods this should work.

 

[Don Jacks]

Yes,I like the 7815 piston and the 6.385 rod as a better overall combination.The big block[6.135] rod and the stock 348 rod are about the same length.

 

[boxerdog]

Don is right on (except I think 409 rod length is 6.010). The Icons are great pistons for the price, but in most cases they are down in the hole about .020 or better, so be prepared to do a mockup . Don's combo with the 6.385 rod is best, I think primarily because of the light piston.

I am just finishing up a "385" which I built mainly to use up stuff I had sitting around and I wanted something "period correct". So I am using early 348 block and heads, 409 crank and rods, Offy 2x4 intake, Isky solid lifter cam (definitely not a modern profile). I used the Icons intended for the stock stroke 348 which are nice pistons but somewhat heavy. So I had to do some serious decking to get to zero. I ported the 379s myself and added 817-size valves. Not a racer at all, but kinda cool. Maybe it really needs a 6x2 setup to be "right"??

So hang in there with Don's combo and I am sure you will be happy, but keep in mind it isn't an SBC and nothing is painless!!

 

[Don Jacks]

When my 348 block was squared up[I think that it took .008-.010 to accomplish],my deck came up to .014 down.What I did was use a .022 steel shim gasket to get my deck to come in at .036[.034 is considered by most as minimum].I'm using a 409 crank,6.385 rods,and the 7815p030 piston.

 

[Clint]

Ok I’ll wait until the block is bored and decked to get what I need and make sure I get it right. I have 817 heads I’m getting from Dan and the 409 crank I already have from Tom, when everybody says “BBC “ I’m assuming it’s the 396/427/454 etc. ? The 6.135 rods are BBC and 6.09 are 409?

Something to ask your machine shop . They might want to have the pistons before they bore. My guy always does.

 

[Tim]

All you guys Rock!!

 

[Tim]

Tim,Have the block bored and squared up,then do a mock up and measure the deck height.Once you determine that,then have the deck milled enough to get the piston to zero deck height.The stock 409 rod length is 6.09,the stock rod length for the big block is 6.135.The 6.385 rod is an aftermarket improvement,much like the 6.0 inch rod for a small block.The price for the 6.135 and the 6.385 is in most cases the same.The 817 head is a really good choice for what you're wanting to accomplish.The 409 length rod and the stock stroke 348 piston will give you a bit more compression,but the torque will be peaky.The longer rod,and the 7815 piston will have a bit less compression,is lighter,and has a broader torque curve,which is better suited in a street car for driving pleasure.

Thanks Don, I’ll source the pistons and rods locallly in case I have an issue. T

 

[Don Jacks]

The rods sourced locally shouldn't be a problem,the part number for the piston is a Show Cars part number and through them ,they are 599.00 per set.They have the best price that I've been able to find,but your friendly neighborhood tax and duty man may cause a signficant increase.

 

[boxerdog]

I always thought that these pistons were only available through Showcars, not directly from Icon as they were made to order?? In any event, they are very nice.

 

[Don Jacks]

The stock stroke ICON piston is a made to order part for Show Cars.The piston that we're talking about[7815] is available on K-B's website listed as a piston for the 348 with the 6.135 rod and a 4 inch stroke.KB pn IC958

 

[Tim]

I will see if I can find the Pistons locally customs and dollar exchange might charge me more than it’s worth to have them shipped from show cars

 

[Tim]

I checked a couple of places and you guys are right as always LOL I can only get them from show cars or KB site

 

[DonSSDD]

Tim, Show Cars will ship USPS, unless pistons would be overweight for USPS. Sometimes they come in that way without tax, sometimes not. If not, use Fedex, they will collect tax, but not charge a huge border fee like UPS.

 

[Tim]

Ok Don I’ll order what I need. I need to see if we have a FedEx account to make things easier.

 

[Don Jacks]

Tim,Are you planning on having this package dyno'd before you put it in the car? It would be interesting to see how well this low compression runs.

 

[Tim]

Yes I am Don, I’m one of those guys that I need to know. Might be January ish by the time it’s all together

 

[427John]

Tim if your heads are indeed 333's(I've never heard of 555's)they are by no means junk unless they have irreparable damage,as models stated before they have the same ports as small port HP heads(HP 348-hyd.lifter 409's)and are capable of not only accepting 2.06/1.72 valves but also 2.19/1.72 valves.While the 2.19/1.72 valves may not be optimum the distance between the guides will allow an intake somewhere between the 2.06 and 2.19 and still allow an exhaust valve larger than a 1.72,those 333's are essentially a clean sheet of paper that will allow you to choose the valves that best suit your combination,and have ports that can support your power goals.The down side is they do have a small combustion chamber that in combination with a double notch block will hamper comp. ratio.Are you sure your block is double notch,it seems when chevy went to the 333's on truck 348's they reverted to the single notch on 348 truck blocks.

 

[Tim]

The heads are definitely 555,s. there is an old forum “double notch block” that we went through what they are and are really odd but have small chambers and valves. Not much we could do with them. We were thinking at the time the engine was from a fire truck. Block is definetly a double notch too.