Refreshing a 351 Cleveland?

[Omie01]

Would you be willing to make one of these intakes for me? I'm not sure if I have the skills to pull all of this off.

 

[Q1SVT]

YES/NO

Omie, I’m not here to sell anything….  I’m in SoCal so shipping 2-ways is $$, really not here to blog either, had to sign up to ask a question last year of a member that purchased an un touched m-code motor built about Oct 1970…   Currently doing a C6 to Tremec change and google search brings me back to a number of ford sites…

The process has been done since a guy purchased a 70 m-code and wanted to upgrade to a 715-780 cfm  ford holley carb and was told it doesn’t fit.

If you have access to a mill and a lathe it’s very simple to do the modification…   the cutter [one that’s 1-11/16] is about $140.00 the rest you can make…  [cannot see you needing more than a 1-11/16” bore carb…for  either motor] A shop most likely would not have the cutter but would have the boring head and charge you about $150.00.  Annular cutter is easier to do, set up the alignment and do the actual cutting.

In the day 2009-12, a couple buddies & I were buying ‘L’ intakes for $20.00 by the dozens and could make good money reselling them after boring them.   Guess people that read them two guys posts on every FORD/Pantera sites,  could not swap intakes fast enough…   lol

Find a mill & lathe, friend or shop and PM me… I’ll walk you through the process .

 

[Q1SVT]

For Machinists or a Hobbyist …   a picture is worth a thousand words.    

I added a comment so there is no questions it’s my tooling  ;^)

 

[Omie01]

I do have a machinist friend, I will show him this post and see if he can help with it. I will keep you posted. Thank You!

 

[boilermaster]

Omie01,

Been watching this one for a while now and a few things are pretty concerning to me as far as what you propose to do with your engine.

Pay particular attention to what Q1svt is trying to tell you about your DYNAMIC compression ratio and then add your transmission , rear axle ratio AND tire size to the puzzle and you may find that 8.0 to 8.3 dynamic may TOO much , especially if you were using say a C6 transmission and tires that would me any taller than stock.

Your window for having a SLUG or an engine that DETONATES very easily in high gear under load becomes VERY narrow.

Take a look at what Ford used for axle for axle ratio's with the higher compression ratio {actual and not advertised, because actual was always lower) and remember what we had for octane back then compared to what we have today.

At any rate, if your cam manufacturer doesn't ask trans, axle ratio and tire size (forgot torque converter if applicable) move on.

Plan on having a distributor that you can easily adjust mechanical advance on.

I see the corner and the paint, I just cant see the direction you are facing, or where the door is.

Boilermaster

 

[Omie01]

Thank You for your interest boilermaster. My plans have changed a bit since first starting this thread, and I guess that looks confusing. I have decided to do a more (stock) geared build as I don't really want to change any transmissions and I would like to keep a fairly strong vacuum signal. So I do understand my compression cannot be very high, and the cam I have picked out is only slightly more aggressive than stock. The only reason I would like to run the "L" manifold is A: to keep stock appearance, and B: because it can be modified to run a Holley carb. 

 

[Sheriff41]

How about using an Edelbrock intake, smooth off the logos, have it blasted to rough up the smoothed areas, and paint it?  You'd retain the stock appearance, lose a few pounds over the iron intake, and be able to use the carb you want.

 

[Omie01]

I have run the Edelbrock performer on a few different engines and while it's bottom end is good, it dies at just over 5000 in my experience. Now mind you, the cams I ran may have impacted that as well. My other issue with the Eddie intake is that it has always bothered me that there is such a Massive port size difference and while I understand that intake to head mismatch is ok, I am just curious to see if there is any difference with a well matched port. Not to mention, I have never tried a factory intake. If I don't like it I can always change it later. Back to modifying the "L" intake. Does anybody know if I can cut the ports like the aftermarket "Boss" intake with the 2 long oval ports? My machinist asked why I don't just duplicate that intake?

 

[Q1SVT]

YES, here is a 625HP 395ci real boss intake…   with a large cam…  12:1 compression…  cutting a four hole intake to the ovals open it up.  Meaning it adds MORE plenum area.  Affects carb signal negatively  at lower RPM ranges [see Hemikiller’s post, he talks about signal…] also manufactures did the ovals to get around stockings different intake to handle different bore sizes & type of carbs  ;^)

Normally a 351C has way more than enough plenum area,  too much, the very large runners provide it.   A four hole is what you’ll want.

jm2c

edited: I’m getting old to push a bagger hot into corners, so my current build/last is to run track days…   drive to and from track

71-73 stangs w/RamAir use that plate under the hood, other RA’s seal to the under side of the hood. Here’s my setup w/more spacers to lengthen the 1-11/16”  runners.   Will not know length until motor is in the e-bay, but believe about 3.5-4.0"…  Got a big street cam for power, but want to move the band around…

 

[Omie01]

Thank you for the very precise info. I will just stick with the 4 holes then. Thank You!!

 

[Q1SVT]

LOL, good, then you will not need the attached link….   it’s a very simple write up but introduces a number of concepts that can be further researched.     laminar–turbulent transition       the spacer(s) & four holes helps to develop laminar flow before that 90* bend ‘turbulent transition    ;^)

I'll check back after 1/1/2022

https://en.wikipedia.org/wiki/Laminar_flow

I

 

[Omie01]

Looks like I may have to modify a spreadbore intake like the Boss one that you did. I have a spreadbore intake, I tried to buy an "L" intake off Ebay, but it was cracked when I got it and I had to ship it back. Not sure if I want to keep cycling through them until I get a good one. Everybody wants over $200 for theirs, and with shipping and tax that gets over $300 real quick.

 

[Q1SVT]

Yeah, the pricing is way up for them again… Guess people figured out those ‘experts’ were wrong lol

FYI, that 625 HP motor was by Ken Maisano - Mascar Auto Body
https://www.facebook.com/photo?fbid=3224916697559057&set=pcb.10157012948907685

People have done modifications on spread bores forever. Good luck, the smaller the better for your build, will work best.

Find a four hole gasket w/1-11/16” bores [or oval] to see/mark-out the area you’ll want to remove. Still use a four hole 1” spacer under carb Wilson Manifold is the only one that sells a 1-11/16”


*** you said your want up to 5,500 RPM… a 351C 2V is a good medium riser intake and works well with a carb like Quick Fuel 2V XP 1412s 600cfm circle track race carb… 1-11/16” like the 2V iirc you’ll need to weld the bottom of the runner @ head flange, but you’re a welder… Will get funny looks at car shows but you’ll beat many between the traffic lights [some say it’s were Vic got his idea of smaller runner 4V, the air gap is a take on 1955ish Pontiac intakes, maybe other brands too]] just a another crazy idea lol

*** QF carbs flow more than there ratings…

 

[BOZJOHN]

So I got a 4 bolt, 4bbl Cleveland from my father that was a running engine when he took it out of the car. It should be a 73 engine because that is what his car is and it had 73 motor mounts on it so I'm guessing it's the small valve OC heads. He said it ran strong and didn't smoke when he took it out, he just wanted more HP so he built a different engine. Upon initial inspection everything looks pretty good. Heads are still pretty clean, no sludge buildup. And the rotating assembly looks very clean. I only have the timing chain cover, valve covers and oil pan off so far. My question is what should I look at to see if I can use the rotating assembly as-is? I don't really want to pay for a full rebuild as this will basically be a backup engine. I have a good source for head rebuild, and I have my own cam bearing installer so I can do a new cam and lifters. I'm thinking I need to plasti-gauge the journals (rods and mains) and check cylinder wall specs. Should I run all new bearings or leave them as is since it worked the way it sits? If I remove the pistons I do have ring groove cleaners so I could run new rings. I do also have a ring grinder. This will be mainly a stock engine so I don't have to go too crazy with parts. Give me your opinions, I'm really torn on this one. I don't NEED another engine BUT....... this is a standard bore 4 bolt block that I think has a lot of life left in it. I will know more as I tear it down but right now it looks like a good candidate for just a refresh and not a full re-build.

Just for information purposes I put together a 72' H-code 351 2V stock bore, stock pistons, Edelbrock 60cc 2.05 valve heads, air gap intake, Comp cams extreme energy CL32-242-4 cam: .218/.224 @ 0.050", .513"/ .520" lift, 110 deg. lobe separation. 750 Holley, 2,400 rpm stahl convertor, C-4, 3.50:1 posi. Absolutely love the way it runs. Runs strong right out of the hole. Have not yet had it Dynoed but would guess somewhere between 350-400 hp. The only problem I ran into during the build is the stock push rods were too short, tring to find my notes, I thinking they were about .150" longer.

 

[71ProjectJunk]

Just for information purposes I put together a 72' H-code 351 2V stock bore, stock pistons, Edelbrock 60cc 2.05 valve heads, air gap intake, Comp cams extreme energy CL32-242-4 cam: .218/.224 @ 0.050", .513"/ .520" lift, 110 deg. lobe separation. 750 Holley, 2,400 rpm stahl convertor, C-4, 3.50:1 posi. Absolutely love the way it runs. Runs strong right out of the hole. Have not yet had it Dynoed but would guess somewhere between 350-400 hp. The only problem I ran into during the build is the stock push rods were too short, tring to find my notes, I thinking they were about .150" longer.

Really good combo of parts. I am thinking of using a cam really close to what you are using there, but with factory quench heads, a 4 speed, and the same 3.50 gears with a trac-lok. Solid daily driver street combo.

 

[Omie01]

Finally got my 73 spreadbore finished, even had it machined for direct mount for a Holley 750, needed clearance for linkage. I think it will work great!! I'll keep you posted!!

 

[BOZJOHN]

Really good combo of parts. I am thinking of using a cam really close to what you are using there, but with factory quench heads, a 4 speed, and the same 3.50 gears with a trac-lok. Solid daily driver street combo.

With a 4 speed you might be able to step the cam up a notch. I just wanted a mild daily driver and I think I accomplished that. With my past experiences it's always good to start milder then go up from there. That way you can log your performance in case you need to upgrade in other places.

 

[71ProjectJunk]

With a 4 speed you might be able to step the cam up a notch. I just wanted a mild daily driver and I think I accomplished that. With my past experiences it's always good to start milder then go up from there. That way you can log your performance in case you need to upgrade in other places.

I may go a tiny bit larger maybe 224 at .050 at the most, but the issue eventually becomes the power brakes. If the vacuum at idle goes under about 15" you will start having issues with your power brakes, and I really do not want to put a vacuum canister or any other such band aids. I have done this long enough to have learned, that an additional 10-20 hp over 5,000 RPM is not going to matter when you end up with drivability issues. If the car had manual brakes, I would probably go to something in the 235 to 240 at .050 and really make quite bit more power and have the engine sounding really nasty, but with the power brakes, it just will not work.