Hey all,

So last weekend I was chasing the cause for milky oil. I've ended up taking everything off besides the timing chain cover and oil pan. Since I have the engine this far apart, I'm considering changing the cam. I have. 71 350 engine with an Edelbrock intake manifold, a converted exhaust manifold from single to dual, and number 7 heads. I plan on driving it on the weekends, it is not a show car. Can you suggest a cam that would get the most HP out of this engine while still running it on pump gas with some reliability? I already have to get new rods because there were 3-4 bent ones, so I don't mind changing their length. Also, is there anything I should automatically replace before putting this engine back together? Any help is always appreciated.

 

I'd look into raising the compression ratio via new pistons.
I'd use a 214/214 on a 110lsa. It would be a custom cam with .472 lift on both,

 

Go with Cutlassefi, great guy to deal with.

 

Do you have a particular spec to look for in a piston or a brand to stick to? I'm hesitant to change the pistons since they look good and the cylinder walls are all in great shape. is upping the compression ratio the best way to increase HP? Could I get the higher CR from modifying the head? I'm planning on sending those out to be reworked anyway.

 

Speed Pro L2321F would be the piston to go with if you're on a budget.
Otherwise you'll need to mill upwards of .060 or more to get the compression where it'll actually start making power.

 

The CR went down the moment the heads came off as the shim style gasket isn't available. I am running the pistons Mark suggested and will also say he is an excellent resource of information and has helped me and many other members.

 

Did you have to bore out your cylinders to fit the new Pistons? The ones of that part number I have found so far are 30 over. Is milling the head 0.060 actually an option? What about flat top pistons?

 

Yes, the cyl needs to be bored and honed after final measurement to set the piston to wall clearance to .004-.005 (with the speed pros). You don't have to go .030 over...but why wouldn't you? It's cheap and you get a perfect new mating surface in a unit that is almost 50 years old.

You can mill the heads to raise the compression ratio. .006 = 1 cc..but again, why? Excessive milling of the heads could make for trouble in terms quench distance and the price at the machine shop.

Mill the heads down .060, stuff flat tops into a 0 deck block and you'll have TOO much compression. I try and contribute on as many of these threads as possible and I can tell you the best way to make these decisions is answer these two questions:

-How much power do you want (Think of this in terms of drive style, don't think of it as a number.) I wanted to be able to smoke the tires from a roll and turn heads at the light while it thumps away.

-How much do you want to spend. That one is numeric

The best part is the people that can really offer the best guidance are right here and most of us are excited to help.

 

i appreciate the help as this is my first restoration and I really don't know what to do. The reason I was trying to avoid boring the block is that up to this point the engine is still in the car and the cylinder walls all look good. Also, I don't want the costs to get out of control but I can ask around and hopefully find someone nearby that does quality work for a reasonable price. I was told that the person who had this car before me was planning on taking it to the track so for all I know it could already have upgraded Pistons and cam in it. For some reason I can't upload pictures to this site from my phone, otherwise I'd let you guys get a look at the internals to help me figure out what I have.

 

Ok,

http://tinypic.com/

This website is what I use to upload photos. I snap a picture with my phone, email it to myself and then uploaded it to the site and then to the forum. Might not be the fastest way but I'm no techy.

Also, even a vacuum reading will tell us a tiny bit about potential upgrades. Let me be clear- no assumptions can be made but if you're pulling 20" of vacuum at idle, most likely, the camshaft is not a "performance" piece. I'm going to duck now as I can see the tomatoes coming..

 

Here is another option I am considering. http://www.rockauto.com/catalog/moreinfo.php?pk=3638025&cc=1217494&jnid=432&jpid=0
Does anyone have any experience with this?

 

Hey guys,

Here are some pics from the tear down.
IMG_3041.JPG

IMG_3045.JPG

IMG_3047.JPG

IMG_3048.JPG

 

Yes, there are lots on here to help, good site. I'd mill the heads if you don't want to pull it apart but it looks to me like you have the better/smaller dish piston in there.

 

So with the smaller dish pistons, how much can I mill the heads and would you still recommend the same cam profile? I'd like a nice burn out and I'm not worried about gas mileage haha

 

Thank you for the clarity Mark, I have more questions about that but I'll PM, don't want to get side tracked.

 

Someone definitely was in there before, I would bet the cam has been changed at some point with the Comp roller tips on there. Are those 6cc or 14cc dish? Definitely don't look like the factory 24cc dish. Any markings on the pistons? If those are 6cc dish, you won't have to do any amount of milling. I would look at 2" or 2.07" intake and 1.625" valves with bowl blending for work on your heads. Get a cam, lifters and springs from Cutlassefi plus a Cloyes billet timing set, gaskets and your done.

 

According to the Sealed Power spec sheet, the L2321F 6cc dish pistons have a .076" deep dish. Factory 6cc dish pistons were .077" deep x 2.54" diameter.

The 14cc pistons had dish dimensions of .130" deep x 2.88" diameter.

Should be easy enough to measure those pistons to determine which ones they are, but just from the pics to me they look like the 6cc version.

 

Thanks for the info guys! I couldn't find any markings on the pistons. I'll go buy a caliper tomorrow to figure out which ones they are. Here are some pictures of the heads.

IMG_3051.JPG

IMG_3052.JPG

 

The casting numbers for the pistons are typically on the underside so you won't see anything from the top.

 

i confirmed that they are the 6cc pistons today is the a measurement that I can make to check if the heads have been milled before? I don't want to take too much off if someone else already has.

 

Have the heads cc'd. Stock #7 heads are listed @ 64cc (however, they have commonly been found to be anywhere from 64-69 from the factory according to some builders on CO). If they cc at, say 59 cc's the head has been milled.

I'm in agreement with olds 307 and 403, have the big valves put in (something I did not do and truly regret) and once all the details of the build are in focus go custom cam (something I'll do with the next build)

 

All you need is a piece of clear plexiglass the size of one chamber and a hole drilled in it. Seal it with grease or petroleum jelly and buy a syringe marked in CC's. You will be within a couple of CC's of the actual size. I have found #8 heads to be on the low side of the factory specs. Also use your caliper to measure from the piston edge to the top of deck with a straight edge across the deck. How far the piston is in the hole affects compression.

 

So I got the crankshaft bolt off with an impact wrench, can I use that to put it back on or will that torque it too much? Also, do I need to put some locktite on it? Thanks again for all the info.

 

The impact is fine, the spec is 120 ft/lbs.

 

The impact I have isn't adjustable and it's rated for up to 230 ft lbs. would that snap the bolt?

 

Trust me, my 230 ft/lbs impact won't even come close to that torque. Unless you air compressor is huge, it won't even remove lug nuts. Just go till it does the tapping tight thing and leave it at that. How did the timing chain look? I am assuming it is a double roller with a mystery cam. Tell us what your heads measure for CC and valve size.

 

I am following these 350 builds, thanks for sharing guys!!

Ryan

 

The timing chain wasn't a double roller, but it did look to be all metal. The heads are out at a machine shop right now getting done over so I can't measure them. The impact I have is electric, not air. $40 special from Harbor Freight this weekend, worth every penny.

 

Oh, there was some slack in the timing chain, is that normal?

 

Some slack is acceptable and normal. I also have 2 electric impacts, one 230 ft/lbs and another 350 ft/lbs that will remove even stubborn nuts.

 

I just got some bad news from my machine shop. I have damaged valve, valve seats, and springs. It will pretty much require a gut job and he estimates $700-800. That is almost the price of new aluminum heads, should I look that way? I believe he is being fair with me, it just seems like a lot of money to get back to stock.

 

I would look at performer RPMS. I don't need to sell em', the numbers speak for themselves.

 

I think I need to pull the cam now too to make sure the valves didn't mess that up as well. Once I start adding this stuff up a crate motor is looking like a good deal. Or maybe an LS swap. I would rather stay all Olds, but it may become cost prohibitive.

 

Only problem with aluminum heads is the chambers will need milled down to factory spec. Get him to order either 2"/1.625" or 2.07"/1.625" valves for your heads and use a bowl hog to open up under the valve. Your cam is probably fine but there should be numbers on it somewhere to indentify it while you have it out. I feel pretty good getting a fresh pair of #6 heads fully machined with 2.07"/1.56" valves with upgraded springs for $400, would cost 3 times that up here. The Olds 350 is a great motor, don't go to the dark side.

 

I for one would hate to see a non-Oldsmobile engine in an Oldsmobile, but whatever floats your boat and fits your budget.

 

If I could get them for $400, I would do that all day long. If I have him put in bigger valves, he said it would run me $1000+. At that price he would be replacing pretty much everything except the rockers and doing a ton of machining. $700 gets me new valves, valve sleeves, springs, locating washers, and some machining. I saw a long block with heads on Rock Auto for $1700, which may be the safe way to go but seems like a lot of money to be back to stock.

 

Contact Mark, Cutlassefi and Bernard Mondello about Procomp heads, should be a bit over $1000 finished. You can get them under $400 each bare. Honestly, you gain a lot of performance for that $300 on your stock heads with the right cam.

 

Just an update, my machinist came back with bad news. The heads were a mix of random parts and pretty much everything needs to be replaced. He now estimates $1200. Since I am unsure of the state of my block it may be best to just swap the whole engine. Does anyone know where I can get a decent engine for a decent price? At this point my goal has shifted from burnouts to just running well. I am leaving toward the one on Rock Auto that is warrantied for 3 years at around $1700, but Famous Brand is not one I have heard of. Has anyone bought anything from them ?

 

Can you post a link to these crate motors?

 

http://www.rockauto.com/catalog/moreinfo.php?pk=3638025&cc=1217449&jnid=434&jpid=0

This is the first one I found.