Refreshing a 351 Cleveland?

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Omie01

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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.

 

c9zx

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If it ran good when removed and it has been stored inside it may need nothing. I assume you have made sure it can be turned over by hand.  If you have access to a leak down tester, spray some lubricant in the spark plug holes and run the test. It will tell you a lot about the condition of the rings and the valve sealing. Since the oil pan is off I'd look at a couple of rod and main bearings. If they look good, put them back on with new aftermarket nuts. Burnish them before final torque. A good visual inspection will tell you what you need to know, Plasti-Gauge is a waste of time in my opinion. If the bearings are good the chances are the cam bearings are good as well. If it has the Nylon/Plastic teeth timing set replace it a decent aftermarket part. Chuck

https://www.mobil.com/en/lubricants/for-personal-vehicles/auto-care/vehicle-maintenance/how-to-do-a-leakdown-test

 

Omie01

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Well, a refresh is a no-go. Water got into the intake and one of the cylinders has a bit of rust in it. Good thing is that it is a standard bore 4 bolt block, so I think I will rebuild it with a pair of 2.19 OC heads since I have a pair. Does anybody have a good piston recommendation to get compression up on a pair of OC heads? 10:1 or so. 

 

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Hemikiller

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What Chuck said. You'll get a modern piston made to your specs, and save on machine work required with the off the shelf stuff to get good compression. Your best bet is to have your machinist determine the minimum overbore required and order the pistons to that spec. If it only needs .010", then no need to go .030". Autotec/Racetec doesn't charge extra for "custom" stuff like that. Get them to zero deck or down a couple thousands, and run an off the shelf FelPro gasket instead of spending $$$ on pricey MLS units that require special finishing. 

 

Q1SVT

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Does anybody have a good piston recommendation to get compression up on a pair of OC heads? 10:1 or so. 
Like said, piston companies can make anything... $$$

JE Pistons have an in stock/made to order Cleveland popup pistons [Boss 302].  You can order them and just pay a few dollars for each change, like move the pin for a 351c rod height, alter the bore like 4.005 etc, cut the dome down to match the compression you want/need, etc

https://auto.jepistons.com/pistons/srp?rwb_cylinder_head=8972&rwb_piston_head_type=8471

picture is a 72 351c QJ four bolt, 4v OC head motor w/JE pistons... compression set 10.2:1

WORKS w/ 2v cleveland heads too

Screen Shot 2021-12-11 at 11.43.09 AM.png

 
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Q1SVT

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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. 
FYI, the 73 CJ 4V small valve head can make power... manley makes SS valves that fit them

Can also have the valve seats cut to be  In 2.19, Ex 1.71... see picture, lower head has the D3 on intake and has been open up

Screen Shot 2021-12-11 at 12.03.05 PM.png

 
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Omie01

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Q1SVT, thank you so much for the pics. I really like those pistons. How are the street manners of that engine? I want to be up front with the fact that I want this to be a bit more mild Cleveland. I currently have a 475 HP cc headed engine and love it, But in the city where I live it's kind of a waste, don't really get to use the power. So with this build I would like to build a good cruiser on a modest budget, Not cheap, just more modest. I will be running exhaust manifolds and probably a port matched Edelbrock Performer so I can run my Ram-Air. On that note, if I use these pistons what would a good hydraulic cam be for it. Trying to stay with 112 LSA for good idle, and staying in a 5000 to 5500 rpm range? Hopefully will be running a 3.00 diff, right now it's a 2.75 so its kind of a slug but it cruises really well.

 

Q1SVT

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Omie01   With 45-50 old parts that have most likely be modified I like to machine as little as possible to them.  Like heads milled... so just what both heads CC the same, and use the piston to get compression to what is needed base ON THE CAM that is chosen...   I only really look at dynamic compress and street C motors that's in the low 8.0-8.3 range  

So, figure out what machining you want/need, what is needed to get the block/heads flat, then in filling out the JE order form you provide that data and they they will set the dome CC's to get you the number you want.

If the 73 heads are rebuildable I would use them... and 4V stock exhaust are good on the street too

The reason people say that the 4V motor are soft down low.. is caused by the lack of compression... get the correct number and it will be fun even in town driving.  So I like the Air Gap, but the fun of having a 4V is having a 4V... so I use the 1970-71 4V 'L' intake [it's the same as the Boss 351C iron instead of AL and it's MORE of a square bore [primiary's are still smaller than the secondary's].  So a Holley square bore 650, 750, does not port match between carb & intake carb plate [see] picture it can easily be corrected.  Cheaper than a $400.00 air gap...

Gearing & cam is dependent on transmission chosen...  ?

there are some bullet cams that have a get sound yet still very mannered ... the motor in the pics has a 230-236 hy-roller, but there are flat tappets too [at or a little smaller].  We go direct to John, but filling out their cam request will get you very good out come.   

See it's not about spending a lot of money... just picking the correct parts combo

JUST my 2 cents...

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9719, 53419 PM.png

 

Omie01

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Why would you use the 73 2.04 heads over the 71 2.19 OC heads? I have both, I just figured the bigger valves would be desirable.

 

Q1SVT

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Q1SVT, thank you so much for the pics.

 I want to be up front with the fact that I want this to be a bit more mild Cleveland. I currently have a 475 HP cc headed engine and love it, But in the city where I live it's kind of a waste, don't really get to use the power. So with this build I would like to build a good cruiser on a modest budget, Not cheap, just more modest.

I will be running exhaust manifolds and probably a port matched Edelbrock Performer so I can run my Ram-Air. On that note, if I use these pistons what would a good hydraulic cam be for it. Trying to stay with 112 LSA for good idle, and staying in a 5000 to 5500 rpm range? Hopefully will be running a 3.00 diff, right now it's a 2.75 so its kind of a slug but it cruises really well.
... the 73 4V are more than enough for what you want.    they will build power / torque   a 2.04 valve is still bigger than other 350-1's running inline valves  ;*)   actual your 72 H-code 2V heads will work better with the 4V Edelbrock intake, the ports are almost a direct fit [the 2V's are a little more oval than the edelbrock intake runners.

Want to run with the 71 big valve head  run them .... just shared a different view.

jm2c

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Valve Area & Curtain.. If you research the Ford Boss 302*, a 70 351C M-code and 71 Boss 351C * and their valve lift you’ll see how ford made them steerable  at lower rpm  ‘velocity through the curtain area by limiting valve lift under .500 ‘  [need to factor out lash…]    ;^)   also, allowing big power potential with greater lift with a cam change

The 4V 2.19 intake valve heads will need very little lift to get you the mild performance

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Omie01

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Can you tell me what size reamer you used for the front holes on intake?

 

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Most likely you’ll need to do all four of them ‘L’ intake…   

The build on that intake used a 4150 750 cfm - carb throttle bore is 1-11/16 and I use a 1-11/16 carb spacer.So you want to bore them for the specific carb ‘throttle bore’ you use.

The difference in size, a reamer will not work, they need to be bored out w/mill boring head… I use an annular cutter,  BUT since there is already a hole you need to follow a re-driling process [like for magnetic drills].    Need a centering arbor guide with ID size of the existing holes and ID of the cutter [stepped guide].   Needed to keep the cutter from moving around at the start of the cut.

For one offs get a machine shop to bore them…   

 

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What Q1 described is the best and proper way to do it. In a pinch, a die grinder with a burr bit and a sanding drum will yield acceptable results. +1 one on what Q1 said about the D3 4V heads and compression. I've seen dyno pulls that prove it, years ago. Chuck

 

Q1SVT

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In a pinch, a die grinder with a burr bit and a sanding drum will yield acceptable results
Sorry, there are many things you can do by hand with a die grinder and a roll/flapper sanding roll…

This is not one of them.   WHY, because there is a 99.9% chance you will damage the wet flow of the OEM ‘L’ intake manifold

The bottom of the four holes have a sharp 90* edge from the factory  for a reason… it forces any fuel on the wall to re-enter the air stream, and the air flowing around the 90* edge , helps to break up the size of any suspended droplets.   Not a lot of places that can happen in the intake runners, if any.

DO NOT radius the bottom/inside of the holes … leaving it squared offed, will help / keep wet flow.   lite de-burring is okay/required lol

jm2c

Footnote: those two guys that did them mule testing yielded acceptable results when they bolted 850 & 950 carbs w/ 1.75 bores on to a 'L'  1.625/1.67-ish four hole intake …   tuff to tune a motor that has TWO Venturi’s within about one inch of each other…  killing carb ability to develop any signal …  BUT the good side?  a lot of people purchased edelbrock & blue thunder intakes.  

 
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c9zx

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Sorry, there are many things you can do by hand with a die grinder and a roll/flapper sanding roll…

This is not one of them.   WHY, because there is a 99.9% chance you will damage the wet flow of the OEM ‘L’ intake manifold

The bottom of the four holes have a sharp 90* edge from the factory  for a reason… it forces any fuel on the wall to re-enter the air stream, and the air flowing around the 90* edge , helps to break up the size of any suspended droplets.   Not a lot of places that can happen in the intake runners, if any.

DO NOT radius the bottom/inside of the holes … leaving it squared offed, will help / keep wet flow.   lite de-burring is okay/required lol

jm2c

Footnote: those two guys that did them mule testing yielded acceptable results when they bolted 850 & 950 carbs w/ 1.75 bores on to a 'L'  1.625/1.67-ish four hole intake …   tuff to tune a motor that has TWO Venturi’s within about one inch of each other…  killing carb ability to develop any signal …  BUT the good side?  a lot of people purchased edelbrock & blue thunder intakes.  
I do not recall saying anything about putting a radius on anything.  Your point about breaking up the suspended droplets is well taken. Chuck

 

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Since we're talking intakes, here's an overhead comparison shot of the D0AE iron vs the D1ZX-DA aluminum Muscle Parts unit, which will clear the throttle plates on an 850 Holley. Q1's method is probably better, as it should give you a stronger signal to the primaries. 

351Cintakes.jpg

 
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Omie01

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So Q1, did you fill the heat channel with some kind of epoxy or something? It looks like you would have very little sealing surface without doing so if you open the primaries up at all.

 

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YES, JB weld high temp… but it was for cosmetic only. More than enough to seal a gasket for 1-11/16".    I & buyers liked that.   I stuff some AL foil in the exhaust crossover and JB that just below the intake head flange, below level then there is no need for cleanup….  If you do both you need to cut a channel in the choke heat riser gasket or drill a small hole in the block off cover to let out air  [hot air expands a lot ]

If you bore them for an 850-950 carb w/1.75 bores then that get close to the crossover passage… We stick weld [high nickel rods] around the area that’s next to the bores, JB weld  the rest, mill the carb pad flat then bore like the 1-11/16” process.

not a great pic but you can make out there is still room…

I know you said you run RamAir, but if you can run a 390-428, 429 stock type gasket  w/ a 1" 1-11/16" four hole spacer do it...

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