351M compression quest, rods?
Thread Starter
|
Elder User
Joined: Dec 2007
Posts: 813
Likes: 6
From: Up Nort Minnesota
351M compression quest, rods?
Hi Guys, please forgive me if I'm repeating a common question here.
I'm wanting to address the anemic comp ratio in a couple of my 351M's and I know there are a couple of aftermarket pistons that help a little with this... But what about a rod swap?
Is there a rod swap that anybody knows of that will get us a little more squish without wrecking stuff? lol!
I'm wanting to address the anemic comp ratio in a couple of my 351M's and I know there are a couple of aftermarket pistons that help a little with this... But what about a rod swap?
Is there a rod swap that anybody knows of that will get us a little more squish without wrecking stuff? lol!
Cargo Master
Joined: Apr 2010
Posts: 2,600
Likes: 64
From: Billings, MT
Hi Guys, please forgive me if I'm repeating a common question here.
I'm wanting to address the anemic comp ratio in a couple of my 351M's and I know there are a couple of aftermarket pistons that help a little with this... But what about a rod swap?
Is there a rod swap that anybody knows of that will get us a little more squish without wrecking stuff? lol!
I'm wanting to address the anemic comp ratio in a couple of my 351M's and I know there are a couple of aftermarket pistons that help a little with this... But what about a rod swap?
Is there a rod swap that anybody knows of that will get us a little more squish without wrecking stuff? lol!
I believe rods between the 351M and 400 are both 6.58 stock, so no, I don't think so.
If you're very careful with the cam selection you could run Aussie closed chamber heads for almost 10 : 1. You'd need a cam with enough intake duration to bleed off a little compression.
Or go with Tim Meyer's pistons and a 400 crank, you'll love the extra torque.
TMeyer, Inc. Precision Automotive Machining
Thread Starter
|
Elder User
Joined: Dec 2007
Posts: 813
Likes: 6
From: Up Nort Minnesota
I know I can stroke my 352, but I don't want to.
I want to keep the displacement where it is, I just want more compression.
I can't find any of the TRW L2466F pistons that I've read about, they supposedly help you get over that 8.5 mark in CR.
I was just curious about maybe a little longer rod with stock pistons.
I want to keep the displacement where it is, I just want more compression.
I can't find any of the TRW L2466F pistons that I've read about, they supposedly help you get over that 8.5 mark in CR.
I was just curious about maybe a little longer rod with stock pistons.
Laughing Gas
Joined: Dec 2012
Posts: 801
Likes: 7
From: Toledo, Ohio
.. What is your objection to converting to a 400? It would prolly be cheaper and simpler than the rod idea you have, you prolly wouldn't lose any MPG, might even gain MPG with higher compression ratio and much better quench, and with a 400, you have a good choice of off the shelf-priced pistons which are even stronger pistons... plus big HP, torque, and fun increases...
.. Hot Rod magazine got into an exotic Ford 351M/400 build up by switching rod brands, which required switching piston brands, head brand, and other expensive changes that ended up costing $6,800 which they thought was 'reasonable', but we don't, not even close...:
http://www.hotrod.com/techarticles/e...d/viewall.html
.. Hot Rod also did an under $2,000 'budget' Ford 400 build, but as usual they threw in some extras to sell their sponsor's parts, so you could prolly do it for a 1/3 to a 1/2 of their cost. Best thing about this article is it may clue you in to how little power your even smaller 351M/400s are actually making stock!:
http://www.hotrod.com/techarticles/e...d/viewall.html
.. Hot Rod magazine got into an exotic Ford 351M/400 build up by switching rod brands, which required switching piston brands, head brand, and other expensive changes that ended up costing $6,800 which they thought was 'reasonable', but we don't, not even close...:
http://www.hotrod.com/techarticles/e...d/viewall.html
.. Hot Rod also did an under $2,000 'budget' Ford 400 build, but as usual they threw in some extras to sell their sponsor's parts, so you could prolly do it for a 1/3 to a 1/2 of their cost. Best thing about this article is it may clue you in to how little power your even smaller 351M/400s are actually making stock!:
http://www.hotrod.com/techarticles/e...d/viewall.html
Elder User
Joined: Dec 2010
Posts: 600
Likes: 1
From: New Carlisle, Ohio
I'd seriously consider going the 400 route. I mean you can get a new crank from your local auto parts store for about 100 bucks then get some 351C pistons (more choices and cheaper) have your rod bushed for the cleveland wrist pin and deck your block. Then you could get a nice quench zone, more torque and overall alot more effeiant engine due to the fact there would be less detionation. At the very least if your dead set on running 351 ci since your already going to have it apart why not just 0 deck the block? It's about 60 bucks.
Laughing Gas
Joined: Dec 2012
Posts: 801
Likes: 7
From: Toledo, Ohio
.. KeithBlack 351C hypereutectic pistons already modded to fit a 351M/400 rod may actually be lower priced through Tim Meyer than other places charge for unmodded ones... and, thus, no need/expense to bush the rods... no need for pricey custom-modded rods... plus, Tim will be happy to supply what other parts/info/advice is needed to finish the conversion...
.. A super low priced build could include used stock '70-'71 351C domed pistons, your 351M rods(bushed), and a 400 crank/bearings kit into your cleanup honed 351M/400 block (ridge-reamed if necessary).... mild performance Summit cam/lifters kit if desired... swap meet used 4 bbl. carb. with adapter to your 2-bbl. intake manifold... Summit exhaust headers/pipes/turbo mufflers... or used Dodge Hemi truck 3" inlet mufflers...
.. A super low priced build could include used stock '70-'71 351C domed pistons, your 351M rods(bushed), and a 400 crank/bearings kit into your cleanup honed 351M/400 block (ridge-reamed if necessary).... mild performance Summit cam/lifters kit if desired... swap meet used 4 bbl. carb. with adapter to your 2-bbl. intake manifold... Summit exhaust headers/pipes/turbo mufflers... or used Dodge Hemi truck 3" inlet mufflers...
Trending Topics
Senior User
Joined: Jan 2013
Posts: 317
Likes: 0
From: NW Ohio
Well the simplist way may not be the best way. since 351c/m/400 heads interchange and they fit on a windsor.... You could do a reverse clevor. 351w heads have a smaller cc but they are inline valves. You can get some cast iron ones fairly cheap and do the water coolant passage modification. After you decide you dont like it, you would be out very little money.
It's the answer for what you want, but not the best answer for the dyno sheet.
It's the answer for what you want, but not the best answer for the dyno sheet.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Elder User
Joined: Jan 2011
Posts: 831
Likes: 1
From: Tanilba bay NSW Australia
cut to basics-forget rods and go with aftermarket pistons. Are you trying to get away with the original pistons/rings so you dont have to pull the engine down for a rebore?
r/r pistons on new rods and back in the same bore may be an idea but dont think it is that easy in practice. especially if you look at the Hot rod article above-the different weights stuffed a lot of things up.
Both those articles are coll-remember rading them 4-5 years back before I my 400 powered LTD-needed all the info I could get-still do LOL
r/r pistons on new rods and back in the same bore may be an idea but dont think it is that easy in practice. especially if you look at the Hot rod article above-the different weights stuffed a lot of things up.
Both those articles are coll-remember rading them 4-5 years back before I my 400 powered LTD-needed all the info I could get-still do LOL
Laughing Gas
Joined: Dec 2012
Posts: 801
Likes: 7
From: Toledo, Ohio
.. Yes, expensive customized rods plus a rebalancing job yields some improvement, but gets expensive fast with rather unimpressive results...
.. The other idea of simply decking the block may require a lot of decking and result in a thin, weak deck surface depending on what pistons are in there now and thus how much has to be cut off...
.. Either way above, you still end up with a 351" with dished pistons and 79cc head chambers... giving a compression ratio still in only high 7's or low 8's...
.. The other idea of simply decking the block may require a lot of decking and result in a thin, weak deck surface depending on what pistons are in there now and thus how much has to be cut off...
.. Either way above, you still end up with a 351" with dished pistons and 79cc head chambers... giving a compression ratio still in only high 7's or low 8's...
Thread
Thread Starter
Forum
Replies
Last Post
pud
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
6
Sep 24, 2006 02:38 PM
boardwalk72
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
2
Aug 6, 2004 08:08 AM
mmidgett
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
3
Jan 24, 2003 07:23 AM
Ford460BBpower
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
3
Sep 8, 2002 03:33 PM