Bad oil sample. engine decision help needed.

Hello, I am once again looking for some advice from you all knowing Buick engine guru's.....

I received my oil sample report on the Skylark 350 in the mail today, not looking real good, I would say that this will be her last summer before I need to tear the engine out.

Report came back Action Required: Potassium and sodium extremely elevated indicating coolant in oil, and also copper and lead quite elevated indicating system wear. This is why I sample...... now to prepare.

So my plan is to go thru another engine over this summer and fall while I enjoy the car, then in the winter I will swap. I have a decision to make now, I can buy a low mileage running 455 complete for $350.00 or a low mileage running 350 complete for $200.00. I would want to pull the heads and pan on either engine to inspect, regasket, probably change cam, etc. Now the 350 is cheaper and will drop right in, but the big block would sure be more fun in the long run. I know I would need to change motor mounts and the radiator, just wondering what kind of can of worms I would be opening to do this swap?

What would you guys do? If I go with the 350 I would want to do the oil mods before I install it so which choice is the least expensive and least headaches?

 

Depends on year of either engines.

 

Depends if you already have $500+ headers for the 350.
Buy them both! Everyone should have a spare engine!

 

Right now there are more performance parts for the 455.
Keeping the 350 will be easier, and I have a feeling the 350 will rise in popularity when the aluminum heads come out.
Forged rods, pistons, roller cams, single plane intake, are already available, and HOPEFULLY a deep oil pan sometime soooon

 

I know the big block is a 74 and the 350 is a 72.

 

Thanks Mark, I am leaning towards the 350 right now just because it is a direct swap, no headaches, but my inner child wants that 455

 

Buy both, those are good prices. Make a chart of ‘pros and cons’ of both (350 is direct swap; 455 will require coil springs, maybe radiator, and so forth). In the mean time, give a little love to the current engine. If you plan to drive it this summer fix your coolant issue.
Patrick

 

I would love to buy both but work has been really slow due to this crazy weather so..... I figure the coolant issue will require pulling heads which kind of ends my season, have to send heads out to machine shop, check engine deck surface, and it goes on and on. This is why I wanted to make it thru the season, I only put about 800-1,000 miles on per year.

 

Buy both....
Put the 350 in....
And build the 455 , while collecting the parts and knowledge for swap. ....Jim

 

Do a gasket set , rings and bearings, front cam bearing on your 350 . Then pipe in a single turbo.

 

Your current coolant leak may not require all that. It might be intake, which is a driveway job. It might be a head gasket, which still can be a driveway job. If you’re limping this thing through the summer, find the leak and change that gasket. No machine shop trip needed.
Patrick

 

Ditch the 350. The 455 swap is easy enough and only a little more work. The car will be worth more with a 455 and way more fun to drive.

 

Key word is WHEN the heads come out..... just saying

 

Might be intake yes. maybe I am overlooking something but just how would you pinpoint the source of this leak? I can pressurize the cooling system but that will only eliminate external leaks. so now what, pull the intake and look at the gasket? I understand it is only a couple gaskets that can be changed in the driveway but how are you sure of the cause of the leak without tearing the engine apart?

 

tried to buy both but the guy would only sell one. which ever he didn't sell he was keeping. I bought the 350. 32,000 mile engine so he says...... we shall see. turns nice, I tore the valve covers off and cut the filter open, looked good so I continued tear down. needs cam bearings, cylinders look good. my problem is that I can not do any project on the cheap, I have to do everything top notch. A smart man would throw rings, gaskets, bearings, and run it, I never claimed to be a smart man. I just cant see having it down this far without raising the compression with some good pistons, maybe 9.5:1..... decent cam, new timing chain, new timing cover and oil pump, aluminum intake, Im already counting the thousands..... damn it.

 

This the guy that was selling the suncoupe?

 

Seeing how you're going down the rabbit hole, this is a good thread to read to consider a stroker build;

http://www.v8buick.com/index.php?threads/the-dyno-numbers-are-in.200499/

You don't have to run boost if you do a stroker, the naturally aspirated dyno numbers @ only around 8.5:1 compression with a flat tappet cam are very impressive. The numbers would be even better set up not to run boost with more compression, around 10:1 and cammed to run more RPM. Depending on how well you have your heads ported(or how well you do it) will dictate how well your stroker build will run.

You'll also be able to run the new SP3 single plane intake to raise the N/A HP to the next level. If you get around 240 cfm of intake flow out of your heads, you could see over 460 HP with the right cam. GL

 

yes, red 72 suncoupe. nice guy.

 

any guess on what kind of money it would take to do the stroker naturally aspirated?

 

Not to much more than a "stock" rebuild and a bit less than as a non-stroker performance build.