I finally got around to rebuilding and upgrading the Y block for my 55 T-Bird altered chassis dragster.

I Originally built the engine in 2010 and it was in the car most of 2011. I broke it the last race of the season. Autopsy showed 2 broked lifters and a wiped out camsaft. I tore it down last spring and sent it to the shop to get checked out. I finally got it back this fall and after upgrading several components it is almost ready to go back on the dyno.

It is 333 cu in 3.83 bore and 3.61 stroke. Cast crank, 2 inch rod journal

Features originally included 6.3 inch Crower rods, Wiseco pistons ,12.1 compression. G heads ported by Joe Craine, an Isky custom cam with 248 duration at .050 and about .500 lift. I ran it with a ported Blue Thunder intake and Hilborn injection. With the 4bbl intake it made 435 horse and 462 hp with the injection. Power peaked at about 6700 rpm. I was within a few 100ths of dipping into the 9's when the valve train broke.

In addition to a broken lifter I had 1 rocker arm seized on the shaft. Pulling the main caps revealed that they had been "walking" in the block register.. When the crank was check it had a couple of stress cracks in it, right at the fillet area.

Given the multiple failures I decided to upgrade in several areas.

I had another cast crank reground, but this time with much more generous fillets in the journals. To prevent further cap walk I had a machine shop turn out some steel main caps that are the same height as the pan rail and fit very snug in the block... I am using an Eaton girdle which sits tight against the top of the steel cap. I am hoping this will give me a very stout bottom end.. I know I should have a billet crank at this point, but the wait is long and the cost is high.. I know of FE guys that put a lot of rpm and horsepower through their 428 cast cranks, so we will see.

I have upgraded to Mummert heads, fully ported by Joe Craine, and flowing like crazy. Also a Mummert intake, also ported by Joe. With the smaller chambers in the heads my compression is up to 13.5

The cause of my valve train failure was not obvious. Some possible causes could be spring harmonics, insufficient guide clearance, material failure in the lifter, or camshaft lobe failure.

To address as many of these problems as I could I did the following..

New tool steel lifters made by Trend Performance. These things are like jewelry with a highly polished and hardened face. full Harland Sharp rocker setup. Comp Cam beehive springs to accomodate .650 lift. New cam by Jones Cam Designs in Denver NC with 268/274 duration at .050 and .635 valve lift. Lobes are nitrided to assure proper hardness.The cam should make max power at 7500 rpm.

Ted says Mummert heads are worth about 70 horse, so I am hoping for 540ish with the carb. The big cam, extended rpm, and higher compression might get me a little more than that. The Hilborn injectors are consistently worth about 30 hp so I am setting a stretch goal of 575 horse for this combo.

Hopefully I will have this engine on the dyno before spring. I will run it with the intake and carb first. Eventually I would also like to switch to Alky with the injectors, and that requires a different setup.

I have attached a couple pictures one showing how the steel main caps and the girdle fit together

8's?

Looks pretty stout Royce!  can't wait to see the numbers.

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

RB: Don't know.. but I would suspect that the lifter breakage you experienced was likely related to the seized rocker on the shaft. Either insufficient clearance & or not quite enough oiling of the valve train, at high RPM. Your cam was an Isky. John Mummert has found that the cam blanks have insufficient depth in the centre journal oiling groove. Was that problem covered in your engine?..

Paul

Looks sweet RB! That bottom end looks bullet proof.

Glen Henderson



Freedom is not Free

Letohatchee, AL

Royce.  Thanks for the pics.  Those are some really serious main caps.  Looks like another ‘Terrorizing Y’ is about to break free.  This aint no plain bullet for sure.

Lorena, Texas (South of Waco)

Looks like hes using Armor Peircing bullets to Me! Great Job!

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

That thing looks great Royce. Can't wait to hear more about it. Especially with the injection you set up.

       A  L  A  N   F  R  A  K  E  S   ~  Tulsa, OK    

That's one wicked looking YBlock Royce, Beautiful!!!!! Now go Kick some scrub booty.

-Gary Burnette-

Paul, I don't know why one of the rocker arms seized... I am confident it was not a lack of oil.. I did all the modifications to make sure a good supply of oil was getting to the rockers.. The seized rocker was very strange. It was not galled or scarred, and none of the other rocker arms showed any signs of wear. There was a tiny area on the rocker arm that had gotten very hot and fused to the rocker shaft about like you put a tack weld in just one small spot.. I am speculating that a piece of metal debris worked its way under the rocker and caused it to fuse in just one small area. Another strange fact is that none of the pushrods were bent.. Normally they act like a fusible link if something tightens up in the valvetrain. In addition the lifter that showed the most carnage was not the one under the seized rocker arm.. Some very strange circumstances indeed.