Piston manuf.????#7028P????
Thread Starter
Racer
Joined: Oct 2009
Posts: 374
Likes: 1
From: Forsyth Illinois
Piston manuf.????#7028P????
I got this back up engine w/a roundie round car,and can't find who the piston manufacturer is.Trying to see the specs for the pistons to figure out compression,etc.The engine looks fresh,but has sit for awhile.
I haven't measured stroke yet,but appears to be 350 bored .030 over.The block is a zero decked March 26th,1969 #618 block,the good 2482 caps,1182 crank w/mallory,and it has aftermarket rod bolts.Don't know anything else.
The pistons are 7028P .030 on the tops.
I'm planning to dis-assemble for inspection,and cleaning,and check the rings,and bearings from sitting,but have a extra set of 2.05 bowtie heads w/1.6 Harlandsharp roller rockers,310 solid flat tappet,and some other cool stuff,and thought about throwing it together as a extra engine w/the spar parts laying around the shop.
Tried to see if they were GM numbers for 69 11 to 1 350 engine,but drawing blanks.
Thanks for your help,and Merry Christmas!
I haven't measured stroke yet,but appears to be 350 bored .030 over.The block is a zero decked March 26th,1969 #618 block,the good 2482 caps,1182 crank w/mallory,and it has aftermarket rod bolts.Don't know anything else.
The pistons are 7028P .030 on the tops.
I'm planning to dis-assemble for inspection,and cleaning,and check the rings,and bearings from sitting,but have a extra set of 2.05 bowtie heads w/1.6 Harlandsharp roller rockers,310 solid flat tappet,and some other cool stuff,and thought about throwing it together as a extra engine w/the spar parts laying around the shop.
Tried to see if they were GM numbers for 69 11 to 1 350 engine,but drawing blanks.
Thanks for your help,and Merry Christmas!
Thread Starter
Racer
Joined: Oct 2009
Posts: 374
Likes: 1
From: Forsyth Illinois
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Exactly what I thought but didn't post cause I wasn't sure. They look like high compression pistons more than 11:1cr 
The TRW part anyway I thought about SpeedPro and also suspect they are a "claimer" piston
Last edited by MotorHead; Dec 16, 2009 at 10:03 AM.
Burning Brakes
Joined: Feb 2005
Posts: 894
Likes: 91
Piston Identify
The pistons are "Speed-Pro's" and they are the equivalent to "TRW" part number L2278F. May be easier to run the "TRW" numbr instead!
Can give you this:
It's for the 350" platform with slight up-stroke (3.562") by offset grinding the large journal 350 rods to the small journal size! Gives you an increase of .041" (nom.) on the stroke.
The C.H. is 1.514", the domes are 10.5 cc (Std. bore), uses a 1/16"-1/16"-1/8" ring pack, LR-194 single pin locks, and weigh 562 grams (nom).
Hope it all helps,
Thanks, Gary in N.Y.
P.S. Compression ratio will be in the area of 12.5:1 with some 64cc heads, mostly depending on all the "real" numbers, gasket thickness, deck height, etc!!
Can give you this:
It's for the 350" platform with slight up-stroke (3.562") by offset grinding the large journal 350 rods to the small journal size! Gives you an increase of .041" (nom.) on the stroke.
The C.H. is 1.514", the domes are 10.5 cc (Std. bore), uses a 1/16"-1/16"-1/8" ring pack, LR-194 single pin locks, and weigh 562 grams (nom).
Hope it all helps,
Thanks, Gary in N.Y.
P.S. Compression ratio will be in the area of 12.5:1 with some 64cc heads, mostly depending on all the "real" numbers, gasket thickness, deck height, etc!!
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
That is a Speed Pro number. I am pretty sure it is also a forged piston. Specialty piston, 364 CI with offset ground crank. Old circle track setup. Check if it does have the offset ground crank. If it does and it is forged this could be a real nice high RPM setup. 75 or 76 CC aluminum heads with good quench would drop the compression down to around 11.5 to 1 and with your 310 cam would rev past 7000 RPM and might run on pump fuel.
Last edited by 63mako; Dec 16, 2009 at 12:37 PM.
Thread Starter
Racer
Joined: Oct 2009
Posts: 374
Likes: 1
From: Forsyth Illinois
Thanks fellas for the replies.I really appreciate it!
Sounds like this could be a cool little RPM engine.The guy said that he paid stupid money for it,and when I saw it on a stand in his garage...I thought it was just some ol' 350 w/some popup.Sounds pretty cool!
I pulled the intake,and one of the heads from the 377 yesterday to see inside,and all is clean,and it has pop ups too,like it was suppose to,but the block on the 400 hasn't been decked,but it looked like the bowtie phase 2 heads w/the 2.05s had been milled to raise the compression on the 377.
By ya all's advice,you said I should run the Brodix IK 180s I have on the 377 vs. the bowtie heads,but now I am worried about the compression nor being high enough since the block isn't zero decked,and the compression on the 364 will be TOO high w/the 64cc bowtie heads shaved.Hmmmmm?????
I will get some pictures of the 377 pistons,and see what ya all think/say about them.
Thanks for the information guys!I looked everywhere to try to pull up that number,and hit a blank.
Merry Christmas!
Sounds like this could be a cool little RPM engine.The guy said that he paid stupid money for it,and when I saw it on a stand in his garage...I thought it was just some ol' 350 w/some popup.Sounds pretty cool!
I pulled the intake,and one of the heads from the 377 yesterday to see inside,and all is clean,and it has pop ups too,like it was suppose to,but the block on the 400 hasn't been decked,but it looked like the bowtie phase 2 heads w/the 2.05s had been milled to raise the compression on the 377.
By ya all's advice,you said I should run the Brodix IK 180s I have on the 377 vs. the bowtie heads,but now I am worried about the compression nor being high enough since the block isn't zero decked,and the compression on the 364 will be TOO high w/the 64cc bowtie heads shaved.Hmmmmm?????
I will get some pictures of the 377 pistons,and see what ya all think/say about them.
Thanks for the information guys!I looked everywhere to try to pull up that number,and hit a blank.
Merry Christmas!
