[Bill Meyer]

I am trying to rebuild a 69 WS 400 for a friend. This is not a drag engine, but a "hot street" type rebuild. It's going in a '69 Judge, so keeping the WS (correct date code/not #'s matching) is important. The block is drilled for 2 bolt caps. The main caps were lost at some point in time.
I have tried 5 sets of main caps on this engine. They are all off (east to west) starting at #4 and getting worse towards the front, with #1 being the worst. The rear main seems to be OK, and could be corrected with a line hone. The others are so far off,with #1 being terrible, that a line hone will not correct the situation. It appears as if the jig? was off the day this was bored at the factory.
The only solution as I see it, would be to buy 4 new caps and rebore and convert to a 4 bolt block. This is at least a $1000 dollar solution, $1300 w/rear .
Have any of you engine builders seen this situation before? And am I missing any other solutions?.
- Thanks for reading -sorry for the post in "Race", but I figured it might get read by more in here. - Bill-

[twinturrbo406]

Originally Posted by Bill Meyer

I am trying to rebuild a 69 WS 400 for a friend. This is not a drag engine, but a "hot street" type rebuild. It's going in a '69 Judge, so keeping the WS (correct date code/not #'s matching) is important. The block is drilled for 2 bolt caps. The main caps were lost at some point in time.
I have tried 5 sets of main caps on this engine. They are all off (east to west) starting at #4 and getting worse towards the front, with #1 being the worst. The rear main seems to be OK, and could be corrected with a line hone. The others are so far off,with #1 being terrible, that a line hone will not correct the situation. It appears as if the jig? was off the day this was bored at the factory.
The only solution as I see it, would be to buy 4 new caps and rebore and convert to a 4 bolt block. This is at least a $1000 dollar solution, $1300 w/rear .
Have any of you engine builders seen this situation before? And am I missing any other solutions?.
- Thanks for reading -sorry for the post in "Race", but I figured it might get read by more in here. - Bill-

...... we've had a situation similar to that, we had to flip some of the caps around and over size the dowels to metric pins and cut the caps then linebore to size, but not sure what yours looks like without pics .... from your description it doesn't sound like ours were that far out .... now a nice set of Billet Splayed Caps are very very nice to have though ...

[Dragncar]

Well, I would find a good used iron rear cap. They are crazy expensive.
And go with billet caps since the fitting and line bore are the bulk of the cost for the job.
You can get the 3 center caps for around 275$, and buy a 2 bolt steel one for 80 more dollars. But you are fine with a iron front cap.
Splayed are nice and I would go that route and did. But if you are not a racer straight is fine and the machinist will want 200$ more for fitting the splayed caps.
But, if you are going to do it might as well go billet steel.
Hey wait, better yet.
PPR had straight ductile iron caps (the best, wish they made them splayed) for a good price. They would be the best straight 4 bolts caps available and I think they are less than steel.

[65nss4spdGTO]

Bill,

As far as being off, we've seen them all over, but I think for this build, this is what I would do. Forget about using the current dowel pins, focus on housing bore size, Get a set of Milodon (3) caps and factory ends, check the thrust cap first, if the clearance is close enough moving the cap without dowel pins, open the holes for alignment. Fit the caps, re-dowel the block, line bore and hone finish.

Calvin Hill
Hill Performance
708-250-7420

[BruceWilkie]

IIRC PPRs 4 bolt caps are Milodons. Fine for what you want and could be used as 2 bolt caps if you were really trimming costs.

[PONTIAC DUDE]

I have used factory caps without the dowels installed to get alignment. torque caps. Then redrill the dowel holes oversize and most of the time can get away with LINE HONING.
Pontiac seem to be a lot closer block to block with cap alignment then most American made engines.

[LenCaverly]

I've run into this problem in the past and I take a used main bearing and grind the tangs off and then put them in the bearing saddle but rotate them 90 degrees , install the cap without the dowels and torque to spec ,then redrill and and ream to the next size dowel. This assures that alignment will be as good as it gets, block will have to be aligne honed to complete job.

Len

[taff2]

I turned up an ali mandrel to fit in the mains saddles and bolted the caps on one at a time before re-drilling and replacing the dowels one side at a time,no need for a line hone ,it was all cock on.

[Bill Meyer]

Thanks for all the ideas!! I've got a full bag of tricks to head to the machine shop with tomorrow. This has become very timely, as most rear main caps are on backorder. Thanks again, Bill

[Tom Vaught]

Originally Posted by taff2

I turned up an ali mandrel to fit in the mains saddles and bolted the caps on one at a time before re-drilling and replacing the dowels one side at a time,no need for a line hone ,it was all cock on.

I have seen that deal performed, as was said, several times with modded used bearings or a mandrel with excellent results.

Good luck.

Tom Vaught