4.5" stroke in 427 Truck tall deck block

[P R S]

I've done several 4.375 cranks in production 454 blocks and getting rods to clear wasn't fun.Never done a 4.5" that wasn't in a Dart or similar aftermarket block,so is there enough room in the production Chevy 427 t/d block or will It get into water/oil galley? Will be a drag race deal so a little block filler is no problem but don't know how close to the main oil galley it will get.Any info is greatly appreciated.....Thanks ,Victor

[pdq67]

I think the old book, "How to Build Monster BBC's", lists that the longest stroke is a 4-5/8" jobber, but as noted you have to do a lot of crankcase grinding.

You come out with something like a 440" to 450"+ engine using the 427 tall deck truck block. Something like 4-3/8" b x 4-5/8" s engine here.

pdq67

[Schurkey]

I've done several 4.375 cranks in production 454 blocks and getting rods to clear wasn't fun.

I was under the impression that the tall-deck 427 blocks with the extra clearance cast-in would take a 4.25 stroke and steel rods without grinding, and a 4.375 stroke and steel rods with little problem. Not all 427 TD blocks had the extra clearance. I believe all the 454 castings had this extra clearance.

Am I wrong?

[John Ross]

I believe this engine was built on the standard deck block:

http://www.twperformanceparts.com/index ... ct_id=5302

JR

[P R S]

Some of the 4.375 were easier than others because of rod selection,same as 4 1/4 as some required more grinding some none at all.But ive never tried to do a 4.5 unless it was an aftermarket.I guess I will find out,just hopefully not the hard way..........Thanks Victor

[Frankshaft]

It's harder, and you risk hitting oil and water. How about this, grind a 4.5 to 2.1,.not offset, just grind journal and maintain stroke, then run a molnar 2.1 journal rod. I believe they are more compact, he has or had those. I know Carrillo has them, or will make them, but kinda defeat s using a production block. Those rods with 625's in em, would be about the same price as a dart sportsman block

[SupStk]

A couple points here, block filler like whats aquired from HardBlock or Moroso will not seal water if you break through. Need to seal with epoxy.
The truck blocks I've had in the shop which has the oil gallery along the pan rail, its the same spot as car engines. I know with Manley and Eagle rods with a 4.375, 2.250 journal there is hardly any material left before breaking through. Anywhere between .025 to .040 according to the sonic tester. Maybe with correct rods a person could go 4.500 but I wouldn't bet the ranch on it.

[DCal]

In the 1980s Nick Arias, Randy Goodwin and I ran a 541 cid truck block with 4.5 stroke Cola crank and BME rods. I believe there was Hardblock in the lower part of the block. Those three companies were only 4 miles apart and there were many trips back and forth to get that assembly to swing.

[Racerrick]

search is your friend. The newer blocks marked 7.0l will clear 4.5 stroke with cylinder notching, the block has relief for the rod bolt.

[pdq67]

I'm sure most are aware of this, but there are no production 454" Tall Deck blocks, only the little 366" and the 427" TD's.

My about a '73 or so 454" truck block swallowed my 4.25" crank with thumb rods to make my 496 with no grinding whatsoever! I did do the bore top notches and the oil pump bolt area.

I figure that it would swallow a 4.375" stroked crank easy!..

I really like the idea of a 9.8" deck height after market block max bored and a 4.375" crank to make a 588", "stealth", engine. But it would probably have to be sleeved to reuse it because of cylinder wear.

pdq67

[vortecpro]

In my own experience 4.310 x 4.375 looked good on the dyno, was a train wreck at the track. My question does this run fast for other people at the track? I've always gone away from stroke after my own track testing with the 4.375 stroke, of course I was using GM oval port heads, I had 822 dyno HP but never got any where near that on the track, but I also had windage issues as well. I also will not have the piston coming out of the bottom of the block, bad for everything.


The oil galley is sleaved with a tube.

[pdq67]

I believe this engine was built on the standard deck block:

http://www.twperformanceparts.com/index ... ct_id=5302

JR

Anybody know the rod length that's in the engine in the link?

pdq67

[tt 383]

In my own experience 4.310 x 4.375 looked good on the dyno, was a train wreck at the track. My question does this run fast for other people at the track? I've always gone away from stroke after my own track testing with the 4.375 stroke, of course I was using GM oval port heads, I had 822 dyno HP but never got any where near that on the track, but I also had windage issues as well. I also will not have the piston coming out of the bottom of the block, bad for everything.


The oil galley is sleaved with a tube.

Interested in any comments on this. Combination I am looking hard at for a TD build. Mark if a standard deck could rid angle be causing a loss in seal, maybe coupled with the extra windage? How drastic was the performance loss? Seems odd a 1/16 on either end could be the only culprit...

[pdq67]

Don't forget that the BBC 8.1L block has a 4.37" stroked crank in it.

If not mistaken, it's all metric, a tall deck, and the head bolt pattern is some different than the Mark IV block. It also has LS- type intake ports.

pdq67

[Schurkey]

it's all metric, a tall deck, and the head bolt pattern is some different than the Mark IV block.

Three head bolts on each side are moved less than a diameter. Makes it really hard to "fix" and re-drill.

Almost like they wanted to prevent the old heads from getting installed on the new block.