[BruceWilkie]

The pilot plate angles, hole diameters are fine. Yeah 3/16" should be fine.

As I've said before the adapter plate hole can be a a small amount larger than the pilot plate.

The pilot hole should be kept "tight fit" but not interference(press) fit to starter.

This allows "fine tuning" of pinion/ring gear clearance within the tolerances before welding it to the adapter plate. (especially if no access to a laser cut or cnc).

With a tight pilot hole, removing/replacing the starter wont require any readjustment and allows you to maintain pinion/ring gear clearance(tooth contact depth) within tolerance of .020"-.030" suggested by most starter manufacturers.

[jdw_poncho]

Thanks for all of the info guys. I just started back on my project and I was out measuring up the block to make a plate. Glad I stopped by to check things out.

[charlie66]

Originally Posted by gavin

I am about to go out for the day but just a few quick notes.I have put a starter together and assembled all the bits. The pictures show it bolts up well but the starter does not engage by enough maybe 1/8" short. And as you said it needs moving inboard as my center was slightly out not much but enough to chew the ends of the gear up.Pic detail is not great but maybe ok to see.Will get back to it later.may put a narrower spacer on end of pinion to see if it will come out more.Over all I believe it will work with minor mods.

Thank you for posting these pictures. Now I understand what's going on between the motor, adapter plate and transmission..

[gavin]

Brent has all the new info and is doing the new drawings. These will be put up in the next few days and has all the defects fixed.I will ask johnta 1 if he will replace the drawings with the new ones. For those of you not computer litrate(like myself) brent has offered to send Ubs sticks to take to your local laser cutter. I beleve he will charge a small fee for this but for all his work that's fair as you can get them for free if you want.Thanks for those have taken the time to improve the drawings I'll will back to you next week with more info.

[johnta1]

Sent them my way when done, Gavin.

[Tom Vaught]

Originally Posted by gavin

What I was really interested in was the hole center placement and that is whats important. Both you and tom come to a similar figure so if I change it to 7.352 it will be close.

Good Job, Gavin, on the extra effort to get the starter in the right location (Hole Center Placement) on the parts as well as help create some info for the other Pontiac Block configurations.

Tom V.

If you assume that the Ansen people knew their jobs, the 55-60 bellhousing offered in the "For Sale" section shows the starter bolt holes to be in line with the centerline of the starter shaft and at approximately at 63 degrees, from horizontal, not at 69 degrees (40 + 29) as in the Wilhite drawing.

[gavin]

Tom on the pic you have put up is that for the 55-60 starter rather than the 61-64? I have compared it to an early bellhousing and bolt placement is similar.Thank you for the input.Thank you johnta 1.I will be back to the island tomorrow so wont be able to check things in the shed so I am hoping I have given Brent all the info.To all that have helped thanks.Regards Gavin.

[BruceWilkie]

My hydramatic bell housing is similar. However the starter center is further outboard. Early ring gear is a larger OD.

A 58 starter the upper bolt or stud on starter has to thread into starter(no access starter side). With starter moved inboard for modern 13.98 ring gear its rather(very)difficult to access bolt or nut with with a transmission or bell housing bolted up. 59-60 starters are a different part number with a different drive.

I don't know if 59-60 starter upper hole threads into starter's housing or has room for a nut or bolt from starter side. Also no idea if its solenoid is located above or below starter or the pilot depth is same as 61-63.

Best bet is 61-64 big car starter. Either Delco or an IMI mini starter from Butler.

[gavin]

New drawing is for 61-63 starter using wilhite drw starter detail and the 7.352 center with stater plate at 3/16" thick for the 55-60 blocks.If one users the plate as was intended by wilhite you make the starter plate .438 thick.It is a shame the wilhite drawing was never corrected as it seem a very good resource and deserving of respect.

[BruceWilkie]

Thanks very much for your efforts Gavin.

Tom V thanks for all your input as well.

I HIGHLY suggest that BEFORE welding the starter pilot plate to the adapter plate(the adapter plate starter hole can be somewhat larger than the pilot hole in the pilot plate. The pilot hole needs to be a snug fit)... mock starter up(with solenoid off so you can manually engage starter pinion to ring gear)... lightly tighten fasteners and check that ring gear/pinion clearance is between .020"-.030"(.025" nominal). With pinion retracted it should also clear ring gear by 1/8" and engaged depth shouldn't bottom drive against ring gear.(wear patterns on several used drives indicate @1/8" before it bottoms)

This is last chance to correct starter position due to tolerance stack up. Such as actual block dowel dowel center to pan rail or vertical centerline dimension(or both) plus any minor machining error. (Same reasons you check an aftermarket bell housing for run out)

This also insures repeatable (in tolerance)clearance if you need to replace starter in the future.

I didnt drill the t400 dowel location until bolting up a bell housing and checking/setting run out. (I used a borrowed Chevy bell as lower 4 bolts are all you need while checking/setting). I zero'd runout, tightened housing down(rechecked runout) then used a greased 5/8 drill bit in a hand drill to lightly start dowel center then later did final drilling on my drill press. FWIW trans dowel holes are smaller than 5/8" as Tom W's print shows . SO WERE several 5/8" drill bits I mic'd!(none a true 5/8) Same thing with 1/2" bit used for block dowels which are not a true 1/2"!!! My dowels are all a tight fit as is my starter pilot. Take things apart and reassemble and they go back together at nominal tolerances I set them to.

Extra work? Yes but worth it. Having been an aircraft mechanic when I was young I tend to be somewhat fussy about tolerances. Even if I had a CNC'd piece I would still have inspected to see that it was well within tolerances and likely make corrections if at or very near outer tolerance range.

[Tom Vaught]

Not a knowledgeable person on the 55-60 stuff at all, Gavin.

Saw the Ansen bell Housing and saw that it had same centerline for the upper and lower mounting holes vs the Willhite drawing which is obviously for another configuration.

Agree 90+% of the drawing, created years ago is close but the math was just a bit off in some cases, as Bruce said. Drill Tolerances, specifications, etc can all stack up to screw up the installation. When you are trying to make a proper adaptor for installation in customers conversions the dimensions become even more critical.

Keep working at it and the Pontiac community will have some great adaptor plates for the early engines to the Turbo 400 trans.

Tom V.

[BruceWilkie]

Originally Posted by Tom Vaught

Good Job, Gavin, on the extra effort to get the starter in the right location (Hole Center Placement) on the parts as well as help create some info for the other Pontiac Block configurations.

Tom V.

If you assume that the Ansen people knew their jobs, the 55-60 bellhousing offered in the "For Sale" section shows the starter bolt holes to be in line with the centerline of the starter shaft and at approximately at 63 degrees, from horizontal, not at 69 degrees (40 + 29) as in the Wilhite drawing.

fwiw
I checked a 56 hydramatic starter pattern angle... Its straight across and at 60 degrees to dowels. Upper starter bolt is 7/16" and lower is 3/8". Upper bolt goes thru a boss from back of bell. Early bell has starter further outboard than a 61 up due to larger diameter ring gear. The starter center was also @ 1/2" higher relative to pan rail.

The housing made a nice template for starting housing bolt holes on my adapter. I started my dowel holes(1st) with a pin drill in my dremel at scribed marks, then on drill press gradually increased hole size. Put dowels in plate and housing over dowels to locate the rest of the block holes.

I've got more pics of my adapter plus some starter info I'll add to the thread later.

[Tom Vaught]

Good Info, Keep up the good work!

Tom V.

[Fast 69]

Looks like a lot of good work is going on with this project. Is anyone going to have an adapter for the 59 style blocks for sale anytime soon of are these all for ones personal use? Im debating on either building my own or just using a later model block.

[BruceWilkie]

Butler sells a 61-64 adapter...

http://www.jbp-pontiac.com/products/...terAdapter.htm

looking at pics it would take very little work to add the 55-60 pattern to it. Material would need to be added in two spots for bolt holes(1 per side) above the dowels and the starter pad would need to be 1/4" thinner.

Here is a pic of mine with arrows pointing to 55-60 pattern other holes are t400.(note mine is drilled for 58 starter but will be revised to 61-64 big car pattern when I make a prettier plate.)

Also a pic of Butlers plate... Excuse my scetching with my mouse... here is approximate areas on Butlers plate that would require welding extra material for 2 of the bolts for early pattern..

[BruceWilkie]

Some starter pics. 58(55-60 style) and a 61-64 big car. Also minis from Butler and Ram Air Restorations. Note bolt pattern of 58 vs 61-64 big car. Also pics arent showing how they are clocked when installed other than where you see cut out.

I'm going to buy a mini for 61-64 vs the stock replacement 61-64 starter because I have a kicked out oil pan and want flexibility in solenoid location for clearance for headers or turbo piping. The 58 works but requires 5/16-3/8 inch pilot plate thickness and upper fastener needs to be a stud. That location makes access difficult as nut ends up under transmission flange. It also put solenoid just about touching a cheap old 3 tube header. If I lower starter on same radius I could probably make starter R+R easier but that doesnt help solenoid to header pipe issues and could make lower bolt tougher to access(especially with oil pan kick out).

The 61-64 starter bolt pattern is offset which resolves R+R issues. The upper stud ends up sufficiently under t400 flange for clearance.(55-60 there was a boss on original bell where bolt came thru bell to mount starter. Not an easy option on t400)
On 61-64 big cars the t400 adapter needs a 7/16 thick starter pilot plate(with 61-64 starter). Because a 55-60 block is 1/4" more recessed from flywheel mounting surface to bell surface the pilot plate only needs to be 3/16" thick.

Alternate starters could be made to work if you want to tackle the challenges. Pilot OD, proper pinion, engagement and disengagement clearance, solenoid location all have to be taken into consideration. Pinion in retracted position should clear the ring gear by 1/8"(or more) , when fully engaged the bendix needs to clear ring gear by @ 1/8" as well. (I base that on wear pattern of various Deloco used starters. There always seems to be @ 1/8" of gear length left un-worn.)

When starter is engaged the pinion-ring gear mesh should be .020-.030". A common thin paper clip typically measures @.024"(mic it if your going to use one.)
Many new style Delco type GM replacement starters from Auto Zone etc come with a rod for a gauge and it is used to measure clearance from starter shaft to ring gear. I think it measures .15?" ??? (I lost mine)

There are nose depth, pilot depth, as well as starter drive length differences on alternate starters as well. I'll post pics of some after this post.

[BruceWilkie]

Here are some starter noses and starter drives.

1st pic is unknown app marine starter, 58 starter, 65-up starter, inline Chevy 6.

2nd pic is 58 starter drive, 65-up starter drive, and drive from the marine starter.

3rd pic is 58 starter, marine starter, 65-up starter, and Chev 6. I tried to clock the first 3 in approximate position they would fit a Pontiac, except 6 cyl starter would end up nose down.

Dont have much info on the marine starter...its old, ugly, functional and was a freebie and told it came off a boat. It rotates correct rotation. I'd need an 11/16" pilot plate to use it and solenoid would clear my pan but not my header. Only ID on it is 430 cast on starter nose. I havent found a cross reference for it.

[BruceWilkie]

Making this adapter is somewhat easy btw. I'm working on a write up that will be easier to follow than my "normal" posting and plan to have some video to go with it. Gavin will be involved as well. So you can either follow the prints hes doing and cut/drill yourself or have your stuff water jetted or laser cut.

Ultimately all the info in one thread and hopefully a sticky. Without all the clutter of various posts and threads.

[gavin]

Brent has finished the drawing and has cut a sample plate and also the starter adapter. one will be to sent to Bruce as soon as I get home next week so he can check it out.I want to check the sample before I send it off to him in case I have given Brent some incorrect info.If I am happy with the sample we will put all the drawings up including the laser instructions.It would probably pay to wait until Bruce has checked it out before you get to carried away.If Bruce thinks we need to change something we will up date the drawing.Sorry if we seem a bit slow but we really want to get this right.

[gavin]

Brent has sent a photo to my phone and I have just worked out how to put it on my pc. There are a few extra holes around the starter we will remove when we put the drawings up but this the one bruce is getting once I check it.