[b-man]

The block plate serves to contain shrapnel from a clutch or flywheel explosion, it's not really there to protect the block. You can bet the block would likely not survive even with the block plate installed, the only thing that really matters is that you personally survive this catastrophic event.

[uneasyrider]

Originally Posted by b-man

The block plate serves to contain shrapnel from a clutch or flywheel explosion, it's not really there to protect the block. You can bet the block would likely not survive even with the block plate installed, the only thing that really matters is that you personally survive this catastrophic event.

b-man is correct. The bell housing is the real key component because it's YOU that matters and if the thing takes a massive dump I doubt the plate will save anything. But, if you want to put it on it won't hurt a thing. I have a Lakewood on my car without the plate and it's all good.

[ITSBACK]

No rush here.
Thank you.

[Chipped Tooth]

No hurry here

Whatever ya need just let me know

[old66tiger]

Wow, what a great guy. Nice to see someone goin out of his way to help others.

[old66tiger]

Wow, what a great guy. Nice to see someone goin out of his way to help others.

[ITSBACK]

Yes it is great when a guy helps out like that. I really appreciate it.

[TSMartin]

I have one of these as well but it's buried out in the garage. I never noticed this until I saw the tumbnail. There are 2 holes in the starter location that look very close to where the bellhousing mounted early starter would bolt up to. I drug out Pete McCarthy's book and looked at the drawing for the adapter plate and those holes in the block plate sure look they're in the same location.

TS

[Tom Vaught]

Be very careful about assuming that the print in Pete's Book is accurate on the starter dimension/location holes. Several people have found errors with that drawing.

Most have had to slot the hole(s) to get the Starter Pinion Gear to actually engage the flywheel in the right spot, (between the teeth). Also I believe that the bell-housing bolts on the 64-up blocks are 3/8" and the early blocks are different (maybe 7/16" if I remember right).

Tom Vaught

[BruceWilkie]

Originally Posted by Tom Vaught

Be very careful about assuming that the print in Pete's Book is accurate on the starter dimension/location holes. Several people have found errors with that drawing.

Most have had to slot the hole(s) to get the Starter Pinion Gear to actually engage the flywheel in the right spot, (between the teeth). Also I believe that the bell-housing bolts on the 64-up blocks are 3/8" and the early blocks are different (maybe 7/16" if I remember right).

Tom Vaught

55-60 for sure used 7/16" bolts not sure 61-64. The ring gear is a different diameter on the 64-earlier blocks (at least with bell mounted starter). The adapter drawing in the book positions the starter relative to that ring gear. I dont have that spec handy. Modern ring gear is 13.98" the early one is 14??? (I think 14-5/8").

I think I have the dimension from crank center to starter shaft center(radius) for use with modern ring gear written on one of my drawings. I'll check on it later.

BTW ...dowel holes... dont enlarge them they center the bell. If Bell is off center you use offset dowels to correct the difference. Early blocks thru 60 the dowel measures .498" nominal not 1/2". The newer blocks the dowel hole is .6216/.6226 NOT 5/8"(.625")

15/32"(.46875") holes for transmission bolts will accomodate 3/8" or 7/16" bolts. That is the hole spec on the adapter drawing. Most modern blocks use 3/8 bolts.

I'll follow up with more data.

[BruceWilkie]

Originally Posted by BruceWilkie

55-60 for sure used 7/16" bolts not sure 61-64. The ring gear is a different diameter on the 64-earlier blocks (at least with bell mounted starter). The adapter drawing in the book positions the starter relative to that ring gear. I dont have that spec handy. Modern ring gear is 13.98" the early one is 14??? (I think 14-5/8").

I think I have the dimension from crank center to starter shaft center(radius) for use with modern ring gear written on one of my drawings. I'll check on it later.

BTW ...dowel holes... dont enlarge them they center the bell. If Bell is off center you use offset dowels to correct the difference. Early blocks thru 60 the dowel measures .498" nominal not 1/2". The newer blocks the dowel hole is .6216/.6226 NOT 5/8"(.625")

15/32"(.46875") holes for transmission bolts will accomodate 3/8" or 7/16" bolts. That is the hole spec on the adapter drawing. Most modern blocks use 3/8 bolts.

I'll follow up with more data.

I did write down the dimension for locating the starter centerline when using a bell mount starter and modern 13.98" ring gear.... From crank centerline to starter center the radius is @ 7.3725". The vertical distance(not radius) to the starter centerline from the dowel horizontal centerline(modern bell) is still 4.565"/4.575"

On the plate itself make the starter pilot hole 3-3/8" to 3.5". Make your pilot plate 3.25" for a tight fit around the starter pilot. Dont drill the bolt holes yet(in either piece).

With plate bolted to block,flywheel/flexplate installed, and solenoid removed from starter...clamp the starter to the plate snug but loose enough to allow hammer tap to move it. actuate pinion into flywheel and check pinion to ring gear mesh. Should be .020"-.030" between outer edge of ring gear tooth and "valley" between pinion teeth. (average paper clip is right around.025" if you need a tool...but mic it 1st).

Once you have that set, tack weld the starter pilot plate to block plate. Recheck gap before final welding.
Then install the solenoid and position starter as you want it and mark the bolt holes.

Not shown in the adapter drawing... Dowel horizontal center to pan rail(crank horizontal center. I checked a few virgin blocks and the dowel center to pan rail measured from 2.328" to 2.330".

The T400 drawing may mislead you on the vertical centerlines off the lower outboard holes and the dowel vertical centerlines.
Crank centerline to dowel centerline is 7.690"
Crank centerline to lower hole centerline is 7.800"
Lower hole centerline to dowel centerline is 1.880"
Middle bolts center to crank centerline is 6.300"
Middle bolts from dowel horizontal centerline to bolt center is 2.500"
Upper bolts centers from crank centerline is 3.540"
Upper bolt centers from dowel horizontal centerline is 6.26"

The starter pilot plate is 7/16" on the 61-64 block adapter.

The 55-60 block the starter pilot plate is thinner because the bell face is recessed more (relative to the crank flange) than 61 up blocks. I used 5/16" plate but you could try 3/8" plate if your starter over engages.(or use a 1/16 shim with the 5/16 plate)
Dowel holes... 0.498" or .6221" ...drill smaller and ream to size... they need to be a very snug fit.

OK... here are the 55-60 pattern dimensions. These can be overlaid on the t400 to 61-64 adapter dimensions to fit a modern trans and 61-64 starter and modern flywheel to to early pattern blocks.

Observe comments above on starter mounting and pilot thickness.

First off Pan rail to dowel centerline was 2.806 on my block (another block with machined rail was 2.774). (good reason not to weld starter pilot till all is fit to block)
Note the early dowels are higher than 61 up blocks and smaller at .498". Early blocks use 7/16" bolts.
Quarter inch plate puts modern bell in same plane as modern block with no crank/flywheel spacer needed. It will require welding nuts on plate(or riv-nuts if aluminum plate) where modern trans bolts will go... except upper two which are very close early to late. (hole enlargement in bell to accomodate 7/16 bolts.)
Also suggest Flat head counter sunk allen head bolts(7/16) to mount plate to early block for clearance reasons.

The dowel vertical center to crank vertical centerline is 6.861"
The lower bolts center to dowel center is 2.32"
The lower bolt center to crank centerline is 6.98"
The middle bolt hole centers are 2.329" from dowel horizontal centerline.
Middle bolt centers are 7.242" from crank vertical centerline.
Upper bolt centers are 5.779" from dowel horizontal centerline.
Upper bolt centers are 3.5525" from crank vertical centerline

BTW IMI has a mini starter for 61-64. A 55-60 starter can work if you change the bolt pattern to straight across. RobbMc has a mini for Buick nail head that has infinite clocking and pilot is same 3.25" the bolt pattern looks like 61-64 Pontiac. RobbMc also has a mini with 3.25 pilot and straight across pattern for Eldorado and Toronado and could be fit as well.

Thanks to Jack Gifford and Taff2 for their dimension info below.

[TSMartin]

I was just making an observation .... not any claims of accuracy.

TS

[GTO Dan]

If you don't use the block plate you are getting better protection than the factory piece but nowhere near the protection the scattershield and block plate provide.

As already stated the block plate is there help contain the flywheel/clutch in the event of catastrophic failure. Don't lose sight of the fact that there are about 20 bolts that attach the blockplate and scattershield to make it like one unit.

I'll never forget the guy on my block (when I was kid in the early 70s) that lost part of his right foot and his right hand when the clutch exploded on his Z28 during a street race.

Lastly if you race at a sanctioned track the scattershield is not legal without the blockplate, all the attachment blots must be present and it can not be modified in anyway...there is a reason.

Be safe.

[Tom Vaught]

Remind me never to line up or drive next to uneasyrider on the street.

I did not understand the function of the plate either many years ago.

As you see more bad events/explosions with the stuff, you get a lot more safety minded for you and your passengers IF you are going to hammer on the car.

I blew up 5 rear axles in my life and they did not fail due to granny shifting.

Tom Vaught

[misterp266]

What about making a larger plate that could also be a rear engine mount plate? Maybe make it .250" thick. I was thinking of doing that with the Lakewood I have. If so, I'd have a plate I'd sell to someone.

Rob...

[uneasyrider]

Originally Posted by Tom Vaught

Remind me never to line up or drive next to uneasyrider on the street.

I did not understand the function of the plate either many years ago.

As you see more bad events/explosions with the stuff, you get a lot more safety minded for you and your passengers IF you are going to hammer on the car.

I blew up 5 rear axles in my life and they did not fail due to granny shifting.

Tom Vaught

"Remind me never to line up or drive next to uneasyrider on the street."

Oh stick it Tom. If I don't know and you didn't then just tell me and everyone else what you learned. Safety is the key, right...?

"I did not understand the function of the plate either many years ago.

As you see more bad events/explosions with the stuff, you get a lot more safety minded for you and your passengers IF you are going to hammer on the car."

[Tom Vaught]

I had the same thought but did not want to "pile on" when the guys were offering to do a couple of people a favor with the STP file and the offering to make a few plates.

That being said, I think that a Rear Engine Plate/ Bell-housing Cover Plate would be an excellent idea for the racer side of the Forums. I too would buy one but we would have to have a good idea of where the ears would need to go on the plate.

Tom Vaught

[GTO Dan]

Originally Posted by Tom Vaught

I had the same thought but did not want to "pile on" when the guys were offering to do a couple of people a favor with the STP file and the offering to make a few plates.

That being said, I think that a Rear Engine Plate/ Bell-housing Cover Plate would be an excellent idea for the racer side of the Forums. I too would buy one but we would have to have a good idea of where the ears would need to go on the plate.

Tom Vaught

Sorry to hijack...I would buy a one piece block plate/mid plate as well. I was going to fab it since I have a plasma cutter but would rather buy to save time.

[Nicks67GTO]

Let me make a suggestion. When you install that lakewood scattersheild.....make sure you get grade 8 allen head bolts to bolt the bellhousing to the block. It makes the install so much easier.

[marks73ta]

If someone made one .250 thick with ears for mounts that would be great. The early 55-60 pattern fits inside of the late pattern and could be used to make an adapter to late bolt patterns. I did this with an Indian Adventures rear motor plate but it is only .125 thick and requires another 1/8 inch spacer to bring it out to proper late bellhousing face dimensions. This .250 plate can then be used as an adaptor. Better yet if someone would add the early bellehousing bolt and dowel pin holes too. The end user would just have to figure out how to attach a starter then. Mark L