: Building Tall Deck 427 need help
Aug 21st, 06, 06:43 PM
I'm building a tall deck 427 and I'm having a tough time finding the right pistons.
Does anyone out there know where to buy a set of pistons for a tall deck?
I'm being told they would be custom made pistons.
My specs are:
Rod length 6.136
Block height 10.200
Aluminum heads with 119cc combustion chambers
Any help would be greatly appreciated
Aug 21st, 06, 06:55 PM
If you are building the engine for performance, you should not run tall deck pistons. If you are just doing a stock rebuild, the tall deck pistons are available. They are on ebay all the time.
If this is a performance build, change the rod length to 6.535" and run a "car" piston. The difference between the car and truck pistons is this: The truck piston is .400" taller and has an additional compression ring. They are not to be used for performance (high rpm) due to their weight.
Aug 21st, 06, 06:58 PM
Is this an opportunity to make a stroker here? Tall Deck? Have you tried Speed 0 Motive?
Aug 21st, 06, 07:04 PM
Chris, will 6.535 car rods fit the original crank journals?
It's a forged crank and I'd like to use it.
Aug 21st, 06, 07:18 PM
Yes, 6.535" rods will fit your stock forged crank journal. They are available for under $400 from Competition products ( www.competitionproducts.com )
Aug 21st, 06, 07:24 PM
maybe you can sell that steel crank to one of the vette guys ($$$) and get yourself a stroker. You got near half an inch to fill, may as well put it in the arm, what's that work out too? 502?
Aug 21st, 06, 07:39 PM
These blocks can be stroked and bored to some BIG cubic inches. If you choose to keep your costs down you can build it with the stock crank and have a very nice engine. I can not argue with cubic inches. I chose to build mine with the stock crank and .400" longer rods. It turned out very well. I like it a lot.
Aug 21st, 06, 08:28 PM
You can do a 525 with that block. That's what I'd do if I had one.
Aug 22nd, 06, 04:43 AM
If you stick with the 3.76 stroke, you can use a piston with 1.27 pin height and run a 7.05" rod. There are several other rod/piston combos that will work. Just start with the deck height of 10.2, subtract half the stroke (1.88) and you arrive at 8.32 which is your rod/piston combo. Eagle makes about as many rod lengths as anyone for a decent budget rod - visit JE's/SRP's website and you can try the math with any number of combinations. You'll be able to do pretty much anything you want - you can put the wrist pin in the oil ring or keep it out, whatever you choose. I'm building a 499 with 1.270 JE pistons and 6.635" Lunati Pro Mod rods in a short deck 4.600 bore block. I have a Lunati Pro Mod crank, they made it 3.75" stroke rather than Chevy's 3.766" (where the hell did they get that stroke length???). HTH
Aug 22nd, 06, 04:50 AM
THANKS for all the great info guys!!!
I'll start pricing out cranks and rods and see what I come up with.
Aug 22nd, 06, 06:54 AM
Are you stuck on 427 cubes or is just because you have the 427TD block? Stroke it and use long rods for lighter weight pistons and a bit less side-loading on the cylinder walls. I'm going with the short stroke to kill off a bit of the bottom end plus the car's a 'vette and I've always thought they were kinda made for each other. Otherwise I'd stuff as much stroke in it as I could fit.
Aug 22nd, 06, 12:40 PM
What about the distributor??? Do I need to use a different distributor due the the increased deck height?
I'm using a dual plane intake which kinda sticks me with the factory spacers. The only intake I found that eliminates the spacers is a single plane. I want low rpm torque and streetability.
I'm seriously thinking about the stroker!!!!!!!!!
I stuck with the 427 because it's a Yenko clone but a few extra cu in never hurt anyone.
Aug 22nd, 06, 03:13 PM
The single plane Team-G tall deck manifold is machined so that a standard distributor will work. All the others will require you to put a slip collar on your distributor and adjust it to fit the tall deck.
Aug 22nd, 06, 07:13 PM
There is no more room in the crankcase than a std deck block. It is a real problem getting a long stroke crank in there without grinding the block to the point you get into water. Whatever stroke crank you use get .400 long rods and use the std piston for that stroke. You must use longer pushrods and a dist with either a sliding collar or one made for a tall deck. You either need an intake made for a truck block or spacers (a pain). By the time you get done it might be easier (cheaper) to find a late 454 block and use you 427 parts in it.
Aug 23rd, 06, 04:25 PM
That said, I figure my '75 454 P/U block will swallow a 4.375" stroked crank with minimal grinding b/c it swallowed my 4.25" crank with NO grinding whatsoever to make my 496!!
AND I figure the 427TD motor is made with the same bottom sand cast molds that the later 454 was made with so the 4.375" crank should fit fine!
As always, imho!!
Aug 23rd, 06, 04:36 PM
I thought the same thing Paul, but when I went to install H-beam rods onto the stock 3.76" crankshaft, the cap screws hit the block casting. I had to grind it for clearance with the stock crank. My block is a marine block and seemed to have a lot more meat than the other tall decks I have built. Perhaps that could have been the difference(?).
Aug 24th, 06, 04:08 PM
I'm using rebuilt truck rods here so maybe it's the rods themselves?
Aug 24th, 06, 06:06 PM
Yes, it was the rods. The stock rods fit just fine.