[MarkS57]

Originally Posted by jhein

No kidding. That is beautiful. Especially the lifter valley.

I'll say. Musta been a great job to be one of the guys hand assembling these things in the Pontiac engine shop.

[johnta1]

Another cool feature is the rear cam gear structure. You don't see that every day. (unless you have an SD, or RAV?)

[mgarblik]

Thought I would answer a couple questions. Skip: SD valve covers are regular production "dripper" covers used on all performance engines beginning in 1971? No baffles in the system. Good friend with a 74 SD reports no oil or smoke ever in the line from valve to the intake. Locomotivebreath: Car was sold at a small dealer in the Marion, OH area. That's around 50 miles north of Columbus. I would have to look up the PHS to get the dealer name. Johnta1: The rear of the block is extensively modified for the dry sump provision and large distributor. Looks like a huge amount of revision was done there. I honestly would love to hear the reasons behind WHY they were so sure all those changes were necessary back there. I have never seen an actual dry sump system as Pontiac intended installed on an SD engine. None pictured on-line either. Don't know how it all would even fit in the bellhousing? All very mysterious. Very cool though.

[Skip Fix]

Guys just out of curiosity was there any baffling in the valve cover of the SDs for the PCV so it did not suck oil?

[PAUL K]

Originally Posted by Skip Fix

Guys just out of curiosity was there any baffling in the valve cover of the SDs for the PCV so it did not suck oil?

This is the factory PCV set up. I think the location of the valve keeps it from sucking oil.

I tried one of the aluminum valley pans with the provision for a PCV valve on an AP block... Even using a baffled grommet it was mosquito abatement.

[locomotivebreath]

Was it sold at a dealership in the Cincy area ?

[Skip Fix]

Mike thanks! I asked because the motor in my 78 the Butler aluminum valley pan sucked oil so I tried one in the valve cover(It has about 15 holes in it for venting, my old KRE had only 3 and did not. Better in the valve cover but was still "fogging for mosquitoes" enough on my test drive a DPS guy pulled me over! Now it just has a breather in the valve cover and no PCV.

[chuckies76ta]

Very nice Mike. Thanks for sharing.

[Dragncar]

The horrible oiling of the Buick V6 was their demise at the Indy 500 when they used to qualify #1 but could not finish the race back in the 80s.

[mgarblik]

Question for the SD guys: I was getting some gaskets and seals together and cleaning some parts. This engine has a 5 tab oil pan with welded-in baffling in the pan. So obviously, it is a replacement oil pan. Previous owner confirms the pan was replaced as part of the overhaul in 1980-81. Anything specific different about the factory SD pan? I assume it was a 3 tab at the rear. Anyone happen to have a pic of the interior? Just curious if the baffling was the same as the one I have. Thanks

[johnta1]

The stock pan had a baffle in it. No windage tray on caps.
Just make sure the corners of the pan at rear have the metal pieces under the bolts that help seal the pan gasket.

[mgarblik]

Yes, I need to order those corner reinforcements. I really like the look of the little trap door H.O racing added to the stock pan baffling. You would never see it and it would add a layer of security cornering and braking. I plan to drive the car when it's up and running. It's never going to see a trailer while I own it. I don't want to have to worry about those giant bearings starving for oil. A few things to think about.

[Skip Fix]

Mike I have an original HO pan on one motor and I bought a trap door form Canton and copied one for another motor in the 81 TA. I did find when using the HO pan autocrossing with road race tires a "stop box" at the end where you had to stop hard would drop the pressure some, but corners no problems.

I never had any luck sealing 3 tab pans. Seal was half round so it would slip easily and it seemed 1/8" too long so it was starting to move just laying it on the pan. I use a dremel to convert them to a 5 tab and use the flat 5 tab seal. Most aftermarket pans are 3 tabs.

[mgarblik]

I was able to spend a few hours looking over and taking more detailed measurements on this SD-455 engine. I have decided to make some small changes in my plans. First thing I did was measure every piston very carefully. These are TRW +.030 factory replacement SD pistons. To my surprise, they were very poorly finished for size. The skirt measurements at the tip varied by .004" through the set!! That's pretty bad, IMO and although pistons are definitely more accurate today, I don't remember them being that bad in general 30 years ago. Under the oil ring measurements vary by .002" through the set. Skirt taper varies from one piston with a negative taper of .0005", to an average taper of .002" on the other 7 which is OK. Overall, pretty disappointed in the quality of the pistons, although they look fine visually. That's why you have to measure everything. So my new plan is to re-hone the block and select fit each piston to a cylinder and set the correct .006" piston to wall clearance. Fortunately, they are all too tight now around .002", so it's just a matter of finish honing. The line hone is similar. Too tight. The housing bores are .0005'-.0007' tighter than I like them. I put them right on spec. and these are slightly tighter than tolerance. My understanding is this was typical 30 years ago as shops were concerned about spinning bearings in large main size performance engines. But since I have to hone the cylinders anyway, I might as well fix the line hone as well. Finally, after some careful thought, I have decided to change out the rod bolts. ARP makes rod bolts specifically for SD-455 rods. The head design is a little different. I hope the weight is similar. Will have to weigh them and see. I am concerned with stretching the original bolts 3 more times. once to measure the rod housings, again to dial bore gauge the oil clearance, and a third time for final assembly. Just too many cycles as these bolts may be original and I don't know how many cycles they already have on them. So a little work ahead to make sure everything is as good as I can get it.

[mgarblik]

Originally Posted by Skip Fix

Mike I have an original HO pan on one motor and I bought a trap door form Canton and copied one for another motor in the 81 TA. I did find when using the HO pan autocrossing with road race tires a "stop box" at the end where you had to stop hard would drop the pressure some, but corners no problems.

I never had any luck sealing 3 tab pans. Seal was half round so it would slip easily and it seemed 1/8" too long so it was starting to move just laying it on the pan. I use a dremel to convert them to a 5 tab and use the flat 5 tab seal. Most aftermarket pans are 3 tabs.

Agree, the 3-tab seal is a lousy design. Over the last 15 years or so, I have had best luck eliminating the seal entirely. I think I will weld up the 5 tab slots and just use a 1/4" bead of RTV. That has been working well for me .

[74SDformula]

This is the oil pan off of my '73 SD TA. As has already been stated, it is just like any other oil pan for that year. I do not use the 3 or 5 tab rubber seals any longer. Have had too many issues with them over the years. I use the long thin cork seal exclusively.

[mgarblik]

Originally Posted by 74SDformula

This is the oil pan off of my '73 SD TA. As has already been stated, it is just like any other oil pan for that year. I do not use the 3 or 5 tab rubber seals any longer. Have had too many issues with them over the years. I use the long thin cork seal exclusively.

Thank you for the picture of your SD-455 pan. The pan on my engine looks exactly the same with the exception of the 5 tab lip for the later seal. PO said that was the PMD replacement pan in the late 70's when he bought it. So they had already purged the 3 tab pans from the parts inventory I guess. Steve25: When I take the heads apart, we can talk some more and I will take pics and get measurements you are interested in. My plan is to just clean them and put them back together and check the springs. The original invoice from A-Hines says guide liners were installed. No other real details. Very hard to read. Hand written and 40 years of faded ink. Heads are assembled and bagged. Probably be a month to 6 weeks before I can get to them. I want to get the short block back together first.

[77 TRASHCAN]

I'm surprised that the pistons were NOT fitted to each cylinder.

Did you figure out if a torque plate was used by previous builder?

I've read a lot here about using the cork rear pan gasket piece, all good!!!

[77 TRASHCAN]

I'm surprised that the pistons were NOT fitted to each cylinder.

Did you figure out if a torque plate was used by previous builder?

I've read a lot here about using the cork rear pan gasket piece, all good!!!

[johnta1]

I also use the cork gasket on rear of pan. (with sealer of course)