RPM Advice Needed
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,326
Likes: 1
From: I live at www.domesticlugnuts.com I sleep in PA
RPM Advice Needed
I am looking for recommendations for the parts to get for the bottom half of my 350. What I would like is to be able to turn 7000 RPM with a compression ratio of 10.5:1 without having to worry about throwing a rod or just exploding the bottom half.
I currently have Holley Heads with 66cc chambers, Lunati Cam 235/240 @ .050", 1.6 Roller Rockers. I will be adding a set of 1 3/4" Long Tube Headers. I'm just not sure what to do with the bottom end to make 7,000 RPM safe to hit once in awhile.
Thank You for any assistance you may offer.
I currently have Holley Heads with 66cc chambers, Lunati Cam 235/240 @ .050", 1.6 Roller Rockers. I will be adding a set of 1 3/4" Long Tube Headers. I'm just not sure what to do with the bottom end to make 7,000 RPM safe to hit once in awhile.
Thank You for any assistance you may offer.
Race Director
Joined: Sep 2004
Posts: 13,793
Likes: 0
From: St. Peters MO Sometimes you have to prove yourself by doing alot of killing or alot of dying...
3 words... forged cryo treatment. oh and ARP bolts all the way through. You need strong internal parts to sustain abuse like that. The things that generally give out are the rods and rod bolts. That leads to other problems once they give out.
Everything must also spin free too without obstructions. Good bearings are a must as well as a solid valve train that won't float a valve at those rpm's. 7000rpm really isn't too much, but you want to make sure that your motor can handle the abuse without grenading under the hood.
Everything must also spin free too without obstructions. Good bearings are a must as well as a solid valve train that won't float a valve at those rpm's. 7000rpm really isn't too much, but you want to make sure that your motor can handle the abuse without grenading under the hood.
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
Likes: 71
From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Well for starters, to do it very safely, a good set of light, forged pistons, forged crank, stout rods and a good oiling system. You'll also need the valve train to be ready for it. You going to use hydraulic or solid lifters?
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,326
Likes: 1
From: I live at www.domesticlugnuts.com I sleep in PA
Hydraulic lifters. Lunati says this cam makes its best HP at 6200 RPM. The entire top half is a kit designed to work together by Holley. I figure that I should allow a few hundred RPM over for shifting. I just don't wish to lose the bottom end.
I have already hit 6,500 RPM a few times, but I just don't trust the engine to stay together to long if I'm doing that. This combo is a blast above 3,000 RPM. In 1st gear it revs just as quick as if in neutral (if not quicker since the 4 barrel is open), 2nd gear only last for about 2 seconds (Got aSlight Wheelspin problem) But it keeps you pinned in your seat.
I have already hit 6,500 RPM a few times, but I just don't trust the engine to stay together to long if I'm doing that. This combo is a blast above 3,000 RPM. In 1st gear it revs just as quick as if in neutral (if not quicker since the 4 barrel is open), 2nd gear only last for about 2 seconds (Got aSlight Wheelspin problem) But it keeps you pinned in your seat.
Pro
Joined: Apr 2003
Posts: 517
Likes: 0
From: South Lyon Michigan
I have a ZZ4 shortblock and I have hit 7000 rpm several times now (I have my rev limiter set at 7000) so far no problems. I would reccomend good bearings, 4-bolt main, good rods, and good piston rings.
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
Likes: 71
From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by Rich & Lisa_84
(Got aSlight Wheelspin problem)
Safety Car
Joined: Apr 2004
Posts: 4,532
Likes: 7
From: Lahaina Hi
Splade main caps H-beam rods good distributer gear new oil pump.
and all the above.
Coat the pistons and make sure you have a good set of head gaskets.
Forged is the word.
I use cola crank eagle h-beam rods and diamond pistons 11 to 1 with the AFR's 220 need the 11.1 pistons.now it's at around 10.3 to 1.
Clevit bearings.Twisted rings I use the juice.
and all the above.
Coat the pistons and make sure you have a good set of head gaskets.
Forged is the word.
I use cola crank eagle h-beam rods and diamond pistons 11 to 1 with the AFR's 220 need the 11.1 pistons.now it's at around 10.3 to 1.
Clevit bearings.Twisted rings I use the juice.
Race Director
Joined: Sep 2004
Posts: 13,793
Likes: 0
From: St. Peters MO Sometimes you have to prove yourself by doing alot of killing or alot of dying...
Cola makes a damn fine crankshaft. I do not have any experience with them, but many of the weekend warriors and Ozark Mountain Powershifters use Cola or Crower and regularly hit 7000+ in the ¼.
For rods... Manley would get my top pick, but there are several very good manufacturers out there. The big thing is to spend the extra $$$ for the ARP bolts. I can not stress that enough.
You may want to contact Lunati also. I believe they have a rotating assembly kit that they can recommend. I know Eagle and I think Scat have one through Summit or Jegs.
For rods... Manley would get my top pick, but there are several very good manufacturers out there. The big thing is to spend the extra $$$ for the ARP bolts. I can not stress that enough.
You may want to contact Lunati also. I believe they have a rotating assembly kit that they can recommend. I know Eagle and I think Scat have one through Summit or Jegs.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
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
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
I used a 4340 scat crank-only about 500 bucks-manley sportsmaster rods and pistons;strong and light, probably overkill for what you're doing, but you get the idea. Plenty of reasonably priced forged kits out there. Scat, C.A.T.,(speedomotive)-Lunati-Callies has a new street crank out. I believe it's the dragonslayer, well under a grand. How much do you want to spend? You should be able to get by on a stock steel crank with good rod bolts and a light piston if need be. Invest in a good balance job
