Classic American cars

Buick 455ci 7.4 litre V8 in for a rebuild

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The Buick big block is one great engine. Big cubic inches making big horsepower in a small package. Approximately 100lbs lighter than a Chevrolet 454 big block, little more than a small block Chevrolet! When this one left the factory it was already putting out around 350 horsepower and 510 lbs. ft. of torque.

So it’s a good engine. Unfortunately it is let down by a poor oiling system. The stock oiling system is ok if you like to drive around town nice and easy but totally inadequate if you like to get serious.

Luckily there is nothing wrong with the Buick that cannot be sorted with a little work and ingenuity.

First thing to do is clean the block down to bare steel and grind off all the casting flash. Finish off with a fine file or grinding wheel to get a good smooth finish. All the time inspect the block, look for cracks etc, particularly near the top of the block just under the cylinder head mating surface(the deck).

Now it goes for a dip in the hot tank. I like it nice and clean for crack testing. If you don’t have a hot tank then wash with Gunk etc and steam clean until perfectly clean! Normally it would be sent to the machine shop for boring now, then put through the cleaning process again but the bores on this one are so good it’s staying at standard and has been final honed for the new pistons. Various oil ways in the block have been drilled to enable greater oil flow to the essential areas.

And don’t forget, before any assembly, clean, clean, clean until you can wipe the block inside and out with a clean lint free cloth and the cloth stays clean.

New cam bearings have been fitted, supplied by TA Performance Products from Scottsdale, Arizona. These are heavy duty bearings, teflon coated and with two grooves running round the back of the bearing to improve oiling to the right lifter gallery. Normally the oil goes to the gallery through the inside of the front cam bearing but these easily get blocked, particularly if you are running a big cam. The front bearing tends to ‘melt’, blocks the oil way with debris and so stops oil getting to the drivers side gallery and that’s not good ! Usually the first you know things have gone wrong is clattering on the drivers side from the lifters and by then it’s to late.

In addition to the grooved cam bearings we have taken out a bit of extra insurance by using a coupling pipe between the rear of the lifter galleries, screwing into the rear of the block instead of the rear gallery plugs. A simple but very effective solution. (SEE PHOTO)

The engine block and associated parts have been painted using Hammerite Smooth Red supplied by the owner.

After careful preparation the paint work has turned out very well indeed.

The original Buick valve covers have been cleaned and painted and will be used until the end of the build, when a pair of chrome covers will be fitted.

The Buick iron heads have been fitted with new hardened exhaust valve seats, new valves, springs, retainers and locks. The new valve guides have been machined to accept teflon seals supplied by POSTON Enterprises. A great improvement over the stock seals.
Valve springs have been adjusted with shims to obtain the required spring pressure.
New rocker shafts and rockers are ready to be fitted once the heads have been fitted to the short block.

Brass core plugs have been fitted and the front oil gallery plugs have been fitted and staked.
Iif you are going for all out performance you can tap the holes and use screw in plugs. Not necessary in this build.
We always use brass core plugs. If a steel core plug is going to corrode you know it will be the most inaccessible one and they always start letting your precious coolant out at the worst possible time!

The stock Buick crank is casting number 1379242. It has been ground 020 on the big ends and 010 on the mains. Oil passages in the crank have been chamfered then the journals were micro polished.

The Poston GS113A Cam is on the installer tool. The tool is about 3 feet long to give good control as the camshaft is inserted into the block. We do not want to damage those precious cam bearings! Camshaft spec’s are 510 lift and 286 duration on the intake and 491 lift and 302 duration on the exhaust.

It’s a hydraulic grind and should have a lumpy idle and be pretty snappy on the throttle.

Always get your pistons ready for fitting, keep everything clean, oil the pistons well and use a good assembly lube on the big ends.
Fit a sleeve on the con rod bolts, make one out of hose if you don’t want to buy the proper thing. They are indespensible, those rod bolts will kill your expensive crank in a second.

Use something firm to tap the pistons. I use a shaped chunk of nylon (seen in the piston photograph), it’s firm and can’t hurt the pistons. Never hit them with a hammer or try to force a piston into the bore. If it won’t go in there is a reason for it, those rings will break very easily. Take the piston out and have a look, make sure the rings are fitting fully into the ring compressor. Always use a good quality ring compressor preferably the one piece type.

With the camshaft in the next thing to do is fit the timing set. We are using a Cloyes double roller set which gives you the choice of standard timing or 4 degrees of advance or retard.

Our timing set is fitted on the standard setting because the camshaft has 4 degrees of advance already in it’s grind, something I didn’t find out until I checked it with a dial gauge and degree wheel. It is not mentioned in the cam literature, you have to check every camshaft every time just to be sure.

This next modification is one that should always be carried out as the Buick big block does not get enough oil to the distributor/camshaft gears and will fail very quickly under severe duty.

As you can see we have tapped into a gallery feed in the front cover. The oil pressure will feed a generous amount of oil directly onto the distributor drive gear and the cam gear. This should eliminate premature wear of both gears, the excess oil then drops down onto the oil pump drive shaft which will help with lubrication in that area and will also splash onto the timing chain.
One thing you must do is ensure the oil feed pipe or union cannot come into contact with any moving parts. The timing chain will be running quite close to the pipe so push the oil feed pipe close to the inside of the cover.
New front timing covers are still available, we are going to use the original cover. When you have finished carrying out the modifications don’t forget to clean the cover meticulously, swarf gets in everywhere.
We will not be cleaning it up yet as we have another mod to do before we are finished with the front cover.

New oil pump gears, piston, spring and gasket ready to be fitted. Setting end float on the gears is essential for good oil pressure and long oil pump life.

New oil pump cover is also ready to be fitted, it’s a new part modified for better oil flow from Poston Enterprises.

The next modification is to make up a camshaft ‘bumper’ to limit fore and aft movement on the camshaft. Movement fore and aft accentuates wear on the cam, bearings and timing chain and also alters the timing so needs to be limited.

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