Hello olds family,
What are your thoughts of flat top sealed power pistons and harland sharp rockers for iron heads?
Pros/Cons??
Thanks

 

All depends on what you're doing.
The HS stuff, especially part 5016, is very nice. But, the roller tip comp cams rockers will get you 90% of what most folks need. You just have to throw away comp's pinch nuts and pushrods.

 

A brand new set of 5001 came up for sale, just wondering if worth to snag.
Looking at a 350 build soon, but nothing radical

 

5001's work for moderate lift cams. The geometry is based on the Ford rocker which *tends to be* OK for Olds. If it's a screaming deal then sure.
5016 is the actual Olds 1.6:1 design.

The apples-to-apples cost comparison is:
HS rockers + guide plates + pushrods + studs
Comp roller tip kit + polylocks + pushrods

To be clear, I think the HS stuff is exceptional and I run the 5016's in my 403. But I used the comp kit in all my prior builds.

As for pistons, Sealed Power makes perfectly acceptable stuff. It all depends on what you want to do and what makes sense for your combo. Piston configuration (material, ring pack, weight, dish size, etc) matters more than specific manufacturer. I'd expect the Sealed Power designs are pretty old, but that's perfectly OK for a mild build. There's not much exciting happening in the world of the small blocks except for what Mark (cutlassefi) is helping bring to market. If you want to get fancy then work with Mark to get a custom piston with a modern ring package. If you want a simpler build then just grab whatever off the shelf fits what you want to do.

 

Wow, thanks for the information. I just purchased an 1980 442 for my son. It's his last year in school coming up, needs something different then the normal crap at school now adays.
So yes, this is a mild build. Is a spare 350 with the car, which is getting rebuilt, 73 block. Sending block in, punching 30 over, true deck and heads, align hone mains. Touch crank if need.
I have a set of 7a's at home, doing a mild port on them. Looking at a lunati cam set. Cam, lifters,springs and timing chain. Nothing big, something to make a tad rough idle. Need to keep the vacuum.
See a portosonic forsale, going to do some research on them. GM HEI distributor, performance curve done to it
Came across a set of L2320F seal power flat top pistons, he recommends total seal rings.
Unsure of the rockers, thinking of comp roller tips.
Found a pair of NOS Olds/Holley covers, seems comp make rollers that fit under standard size covers. And of course, headers are going in.
If need, will put a stall. Engine is out, so easy to change. 2.73 gears, think will be putting 3.42

 

The sealed power flat tops work but for a few more bucks you can get a much better , lighter pistons what will make more power.

Now as for the rocker arms. I have been running the PRW stainless steel 1.6 rocker arms for a ford 302 . No issues have had a few sets on various engines including a ford I built recently lol. I bought them on ebay for 120 bucks . Just FWIW. I have been spinning my new 355 to 7k on a few test hits at the shop lot and have been beating on it on the street a bit shaking the new combo out. My last combo I ran the same PRW rocker arms with no issues but was only spinning it to 6300 rpm ( that engine had speed pro flat tops)

 

Make sure those valve covers fit with the accessory brackets. Some are too tall and have clearance issues.

 

Build is for my son, so he dont need that much power. Freshen up a 350 with a bit of punch will be good for his first car.
The sealed power were decent price. 350 CND
The PRW fit under stock height covers?

 

Okay thanks for the tip

 

My last 355 was mild and ran 12.20's and it was nothing fancy. My old basic 350 ran 13.7's in the 1/4 mile with mostly stock components. The right work in the right places pays off. Your son is gonna have a hard time keeping tread on them tires lol. As for the Prw's fitting stock covers I dont know. I always have ran the tall moroso valve covers.

 

The rockers don't interfere with the covers under most circumstances. The polylocks cause problems first. Get the short 1" polylocks.

I run the Oldsmobile stamped covers which are smaller in the corners, so I run a 3/8" spacer and a thick metal/rubber gasket. Still fits under the A/C bracket. Standard valve covers won't have any problem. Use a thick gasket for insurance.

 

You don't need the expensive roller rockers for a mild build - they don't add horsepower.

The Comp roller tips are perfect for a mild build.

There is a video on Motor Trend TV that has a dyno test of all types of rockers.

You would be surprised at the outcome.

 

Awesome. Thanks, will check it out.

 

What Octane are you planning on running? You could end up at 10+ to 1 compression.

 

Thought 87, but I guess will be 91 or unless can put thicker head gaskets

 

My last 350 with a .030 over bore .025 piston to deck height clearance, .040 head gaskets and my #6 heads milled .024 i had 9.97 to 1 compression. With the flattops

 

What did you run for fuel?

 

Depnding on the day and what I was doing. 91 would be fine for the daily usage with a good tune. If i was racing and making the drive to the track and back ., 93 octane. On some occasions on hot days i would get some light pinging coming off a stop light usually after a long day at the drag strip with the engine being heat soaked. I'm currently running 10.25 to 1 compression on iron heads but the chambers are polished and that helps keep hot spots down. Still running 93 octane.

 

Get the LF2321 6cc dish forged pistons or even better the 10cc Mahle forged pistons in the 4.065" oversize, if the block will clean up with a hone at the machine shop. If it needs an overbore, then get the 4.100" oversize. They will also be less in the hole than the Sealed Power/Speedpro forged pistons, much lighter and a way more modern ring pack.

 

I belive price and availability was the reason he was doing the speed pro flat tops.

 

The car is for my son, his last year in high school.
So nothing too special. Found sealed power pistons 30 over for cheap. I have a set of 7a's, will do a mild port on them. Thinking of an edlebrock intake. Lunati cam set, nothing nuts. Want to keep vacuum.
Block will be punched 30 over, align hone,true the deck and block.

 

My build will be different, that's the motor I will put money into

 

Dumping this thread, making a new 1

 

Started new thread in small blocks