has anyone used flat top Pistons in a 350? How did it work out?

 

Um, the factory did in the W-31 motors. I'd say that worked out pretty well.

 

Hi Kermit sorry on your first post you weren't greeted properly such as welcome aboard instead of receiving a response starting w "um". I'm Dean hope your experience is a good one here.


Any rate the flat tops work extremely well in the 350's. In 68/69 the Ram Rod and W-31's ravaged thru the E and F classes , cant speak on 70's success.


Wish you the best with your project. Dean

 

Yes, the flat top pistons can make a great 350
beware of too much compression as in you have buy premium or racing fuel to run the thing.

What is your goal, and can you afford racing fuel all the time?

Oh, and welcome aboard.

Where's your photos? If you have pix stored on the internet at say imageshack.com, just use that yellow icon that looks like a postcard, or use the "advanced" posting option to get 'em right off your computer.

If only we had a sticky with "How To.... 101" here somewhere.

 

yeah come on mr mod were trying to paint the walls and spiffy the place up...hope i'm not off topic

 

Condescension really sucks.
Welcome and good luck with your build. I am almost done with my stroker incorporating ICON flat top Chev pistons.

 

Thanks for the welcome.
I admit I don't know every thing about cars but some people have to compensate for their short comings.
I was thinking about installing my 69 400 442 4 peed motor in my 74 Omega S hatchback,or maybe the 468 Toronado engine I just finished.
I mostly see posts about BB olds but more SB stuff would be great.
I will try to post some photos later,and I will overlook the condescension thing. Thanks Guys !

 

yeah sorry that was your first experience but interesting combo.
The 350's are a great motor big bore and short stroke , unfortunately the 68/69 400's weren't the best due to opposite long stroke and small bore. But they have great torque. Best to you and your projects.

 

Hello Kernit,

Welcome!!!!
I have alot of experience with using flat top pistons in 350 Olds engines in alot of different applications. A couple different types exist for example, cast, forged, ect, each having their advantages and disadvantages.
To help you with your descision I would need to know what your intensions are with the car and what you want to achive out of the engine.

Here are some basic things to think about before deciding,
1. budget
2. if you want to run it on pump gas or race feul
(this will determine what true compression ration you plan to run)
3.Usage (street cruiser, racing, ect)
4.desired horsepower

hope this helps

Steve

 

I'm sorry about that. I did not see the low post number. Welcome. I did not intend to slam a newbie - I thought I recognized the screen name, but clearly I was wrong.

 

Joe just being frank here shouldn't matter the post number or who it is. No one wins when sarcasm is used to answer a question.
Furthermore no one wants to feel stupid or belittled when being answered.

 

So wait I could put flat top pistons in my engine without having to do any other work if I wanted too

 

Criticism accepted. It does get frustrating when people who should know better can't be bothered to search for info that's been covered many times. That comment does NOT apply in this case, however. Again, sorry for the comment.

 

No problem if the truth is told we all have probably done something similar.
My heads are #8 so Idon't think compression will be a problem.I built the 468 for this car but changing from SB to BB always brings challenges like exhaust clearances. I have BB headers and stock cast manifolds and don't mind using either. The car will be a street car with an occasional trip to test and tune night. Don't want any overheating or drivability problems.
Also,has anyone found and decent looking bumpers for the 70's Omegas?

 

kermit, your post title says "Flat top 74 350". If by that you mean an original 1974 engine with the #8 heads, then yes, flat top pistons would be a wise choice.

The '73-76 350s used #8 heads with large (79cc?) combustion chambers and ~14cc dished pistons to achieve ~ 8:1 compression ratio, so going to flat top pistons removes 14cc and therefore compression goes up nicely.

edit: was typing while you posted the above.

 

Welcome !Joe P is in the know about a lot of things!! He did say he was sorry! We all make mistakes! Joe and i have not always seen eye to but i respect the man and give credit where it is due. I have never met the man but read several of his post. Again welcome.

 

Your no. 8 heads have about 80-ish CC chambers. The flattops and the thicker FelPro head gaskets will only give you mid-9s CR.

If you mean that you plan to use BBO headers or manifolds on the 350, the manifolds won't work. While they bolt to the heads, they will not clear the motor mounts, starter, or oil filter adapter due to the shorter deck height on the SBO. BBO headers sometimes can be made to work on an SBO, depending on the particular manufacturer's pipe layout. Unfortunately, even if you can get them in the chassis, they will hang down further, again due to the shorter deck height.

 

I think head gaskets would be required, and you open a BIG can of mitaswell sauce also.

But, yes, you can just dismantle, insert flat top pistons, and reassemble.

Me, my mitaswell repellent is not that strong, I would have to do freeze plugs, bearings, clean out all the oil passages, main seals, etc.

 

Sorry I was not clear.The BBO manifolds and headers I have I was going to use with my BB in the Omega. However I am not sure about any clearance issues in the Omega.
Does anyone have experience with this swap?

 

Just curious; this would require 93+ octane, right? Also, other than the HUGE combustion chambers, do #8's flow decent? I was considering a head swap for mine, but have been considering a piston swap instead. The only "cheap" gas here is 86 octane though

 

A 9:1 or 9.5:1 motor should run fine on regular, though 86 octane seems low for regular.

 

We do Chris. It's in the Newbie section second from the top: https://classicoldsmobile.com/forums...-pictures.html

 

Cool, thanks. I'm in Japan and we only have low grade 86 octane) on base. Off base has low and high octane (86 and 95 respectively) but it costs about double.