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Joined
Aug 21, 2015
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Location
Tucson
My Car
1973 Mustang Sportsroof. Currently a work in progress!!!
.....It's the bottom end of your 351C.

So now I have a dilemma. After spending $2800.00 to get my 2v heads done right and after driving for about 50 miles, the Cleveland has a knock in the bottom.

:mad:

Rebuild it? Replace with a Short block, reusing the 2v heads - go all out for the V4?

Or set it on fire in the drive way.

The engine isn't original to the car - in fact the car was born with 302. So I don't have to worry about that.

But having a Cleveland is cool...growing up in GM family...anytime I heard Ford talk a 351 Cleveland engine was mentioned and I do like the look of them under the hood.

Keeping it a V2 will be less expensive but I think I'd like more power - how much can you get out of a V2 351C? (w/o super charging/turbo/NOS)

Thoughts? Suggestions?

Tim

 
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I run a 2v 351C with Eldelbrock manifold and 4V carb, big cam, HEI and long tubes.

I'm not sure I'd take 4V heads and put them on if they were free. The reason

is the 2V head/combo of parts on my engine is really impressive power wise and

is a real tire fryer.

The best part is I run regular pump gas with no pinging issues

EVER with a lot of timing.

I figure if I had 4V heads I would have to run premium fuel or additives and

may have to take timing out to prevent pre-ignition.

However if I get a Pantera 8V intake and carbs cheap I will have some 2V heads for sale.

My 2 cents

Paul

 
i dont completely understand your post.

it will be helpful if you supply a lot more info.

what exactly did they do on your factory 2v iron heads that cost two thousand eight hundred dollars? . a set of good aluminum heads that will make 700 hp and weigh 50 lbs less are far less than that.

if you want quicker acceleration, you can install numerically higher gears but the it will turn more rpm on the freeway.

if you want big power in the lower rpm range, you can buy a 393 stroker kit . summit and chp ad a few others sell them . this will allow you to use numerically low gears like 3.00 if you want.

if you want big hp from a 351 without any power adders like nitrous or a super charger etc, you will need at least 3.43 gears and more likely 3.50 to 3.73 and a high stall converter if you use an auto trans . for middle of the road power and not spinning the engine very high at 70 mph, you can get away with as low as 3.25 gears.

to help you better, we need the flow numbers and setup they used to flow them if your heads were ported . if they were not ported, we don't need the numbers.

.

 
First thing are you sure it is a crank knock? Have you listened to the engine with scope or a solid wooden stick. Have you checked the pulleys none loose? Lots of things can cause a knock be sure before you pull it.

Build what you think you will like. Just do not put too much racing stuff in an engine you intend to drive on the street it will not last.

My thoughts,

David

 
Head work:

Bronze valve guides,

stainless 1 piece valves with good quality MATCHING retainers

proper 3 angle valve job.

Springs matched to cam and set up to proper height and have the pressure checked.

Hardened seats

i dont completely understand your post.

it will be helpful if you supply a lot more info.

what exactly did they do on your factory 2v iron heads that cost two thousand eight hundred dollars? . a set of good aluminum heads that will make 700 hp and weigh 50 lbs less are far less than that.

if you want quicker acceleration, you can install numerically higher gears but the it will turn more rpm on the freeway.

if you want big power in the lower rpm range, you can buy a 393 stroker kit . summit and chp ad a few others sell them . this will allow you to use numerically low gears like 3.00 if you want.

if you want big hp from a 351 without any power adders like nitrous or a super charger etc, you will need at least 3.43 gears and more likely 3.50 to 3.73 and a high stall converter if you use an auto trans . for middle of the road power and not spinning the engine very high at 70 mph, you can get away with as low as 3.25 gears.

to help you better, we need the flow numbers and setup they used to flow them if your heads were ported . if they were not ported, we don't need the numbers.

.


I missed that $2800 for heads is way up there?

Agree with Barnett
That's installed.


Yes, I'm sure. I listened to it with a long screw driver. Took it down to a shop to double check the used a scope. It was confirmed.

Of course I don't know where this engine has been or even how many miles are actually on it. I know the heads are good.

My questions - just to see the what setup some of the readers were using.

My initial goal was just to get it running well with the Cleveland that's in it and work on the rest of the car and then at some point decide what to do with the engine....but this changes the plan somewhat. Redoing the heads was necessary because it bent a rod.

Of course this is my first with an automatic trans so adding power it different then with a manual four speed.

First thing are you sure it is a crank knock? Have you listened to the engine with scope or a solid wooden stick. Have you checked the pulleys none loose? Lots of things can cause a knock be sure before you pull it.

Build what you think you will like. Just do not put too much racing stuff in an engine you intend to drive on the street it will not last.

My thoughts,

David
 
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Talk about confusion!! In your last post, you stated a bent rod.. Was it a push rod or a piston rod.. ? Rebuilding the cylinder heads will not cause a lower end knock.. That problem existed before the heads came off.. (Unless, of course, you went out and had some high rpm fun with the car after putting it back together). We don't know that.

Let's say all else is good and there is a low end knock.. There are crank shaft kits out there which can be installed complete with rod and main bearings, which is a lot cheaper than replacing the engine.

May I also add that the oil and filter should have been changed after installing the heads because contaminates like antifreeze can run down into the oil pan and be sent thru the engine when it's running..

Just my opinion based on almost 60 years of experience with these older cars.. Not meant to criticize.

 
Buy a 408 stroker short block, put your newly rebuilt heads on it, get a nice 4 barrel carb and intake, install hedman longtube headers and a decent exhaust. Enjoy your new found power;)

 
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It was a push rod that was bent. That's why the heads had to be done.

Oil change was done and the coolant flushed.

Thanks for the reply.

Talk about confusion!! In your last post, you stated a bent rod.. Was it a push rod or a piston rod.. ? Rebuilding the cylinder heads will not cause a lower end knock.. That problem existed before the heads came off.. (Unless, of course, you went out and had some high rpm fun with the car after putting it back together). We don't know that.

Let's say all else is good and there is a low end knock.. There are crank shaft kits out there which can be installed complete with rod and main bearings, which is a lot cheaper than replacing the engine.

May I also add that the oil and filter should have been changed after installing the heads because contaminates like antifreeze can run down into the oil pan and be sent thru the engine when it's running..

Just my opinion based on almost 60 years of experience with these older cars.. Not meant to criticize.
 
It was a push rod that was bent. That's why the heads had to be done.
I hope it wasn't the same machine shop that suggested the bent pushrod necessitated "fixing" the heads... Unless they were truly mileaged-out, please don't go back there. Ever.

Worn cam/ lifters or rocker arm(s) will do that, not much else on a stock Cleveland will IMO.

And, to consider worn components, the top and bottom ends probably wore together. Yep, the knock was and probably has been there. Depending on intended use, I'd simply pop the rod/main caps and have a look. Sure, there's going to be wear, but maybe just sliding new bearings in place will get you cruisin' again.

Many others will poo-poo my suggestion, but it's worked for me on vehicles with literally a zero dollar budget in mind.

Not meaning to pile on man, believe me. I just hate to see someone soured over misguidance.

 
I agree with Pete, pull the main caps one at a time, take a look at the crankshaft, see if there's any scoring. If not, replace all of the main and rod bearings, getting the oil pan off and replacing the rear main seal are the toughest part of the job.

When the heads were off did you check the cylinder for a ridge and wear/scoring? Was it burning oil?

 
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It was a push rod that was bent. That's why the heads had to be done.
I hope it wasn't the same machine shop that suggested the bent pushrod necessitated "fixing" the heads... Unless they were truly mileaged-out, please don't go back there. Ever.

 


As best as I can tell the original 302 was replaces with a 351C, which was seized when the previous owner purchased the car as a project for him and his done. The current 351C was pulled from a junk yard and it wasn't seized so they stuck it in and replaced the water pump. So I was sure the heads needed "doing". Just wasn't going to do them so soon.


 


I did forget to mention that I had the shop but in two motor mounts and transmission mount when the heads were done...so the $2800 was just heads.


 

 


This was the one of the valves. Clearly this has been firing but not opening.




Worn cam/ lifters or rocker arm(s) will do that, not much else on a stock Cleveland will IMO.

And, to consider worn components, the top and bottom ends probably wore together. Yep, the knock was and probably has been there. Depending on intended use, I'd simply pop the rod/main caps and have a look. Sure, there's going to be wear, but maybe just sliding new bearings in place will get you cruisin' again.

Many others will poo-poo my suggestion, but it's worked for me on vehicles with literally a zero dollar budget in mind.

Not meaning to pile on man, believe me. I just hate to see someone soured over misguidance.
 
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Motoarts is spot on... Good advice..

Quite a few years ago, we had several GM 350 engines come into the shop with a low end knock.. After many times pulling the oil pans, it was discovered that they had bad cam shafts causing the knock. Not saying this is your issue, but where you had a bent push rod, I'd also look at the camshaft.. Pull the intake back off and check it out..

Just a suggestion before pulling the main and rod bearinigs..

 
Such a timely thread for me. My van's 351w started knocking and I haven't explored figuring out why just yet. It is seldom driven so I stopped driving it altogether. I'm hoping it's just a lifter.

Back to Tim's knocking issue. I would rebuild it. That way you know what's in there.

 
That could actually be saved with a long Time Sert and low torque on the bolt of 12 to 14 ft lbs just as a precaution . I would torque all the other bolts to the proper spec and would use grade 8 bolts with grade 8 lock washers in at least the holes around that area . I would also use a thick gasket . Some brands are thicker than others . I would use Permatex Ultra Grey Gasket Maker and let it sit for 24 hours before use.

I would also check the bore and if it needs to go .040" over, I would probably pass but if you are still interested even if it needs to go .040", I would at least have it sonic checked . Also look thru the freeze plug holes at the amount of scaling or pitting in the cylinder liners.

......................
images


 
Thanks!!!!:thankyouyellow:

That could actually be saved with a long Time Sert and low torque on the bolt of 12 to 14 ft lbs just as a precaution . I would torque all the other bolts to the proper spec and would use grade 8 bolts with grade 8 lock washers in at least the holes around that area . I would also use a thick gasket . Some brands are thicker than others . I would use Permatex Ultra Grey Gasket Maker and let it sit for 24 hours before use.

I would also check the bore and if it needs to go .040" over, I would probably pass but if you are still interested even if it needs to go .040", I would at least have it sonic checked . Also look thru the freeze plug holes at the amount of scaling or pitting in the cylinder liners.

......................
images
 
Tim,

I know you are in AZ I would keep looking for a good block. I turned down two 351 H code blocks with cranks, rods and pans std. bore for $100 each on one of my parts buying trips. The two bolt main blocks do not bring much even thought they are exactly the same as the 4 bolt just not machined for the 4 bolt caps. I doubt I could sell one here is why I did not buy. It is like 289 nobody needs one here so very cheap. I say that but if I had to have one the prices would go up, lol.

So if time allows you to do some shopping you might find an engine and other parts you need from one seller. Get on cl and do some searching before buying quick.

My 72 Q vert only cost $5,500 with a newly rebuilt engine, never fired, on the engine stand, MSD, one piece valves, roller rockers, headers, etc. and new rebuilt C-6 along with the car, ram air and tons of parts. Of course the engine was way overbuilt from my taste so I will tear down and remove the hot cam and triple valve springs for sure. Some would say that was a lucky find but it was on cl for over 2 months with no interest. If I was going to go for speed I would not build one of these cars I would get a Pinto or Maverick. Lightest body I could find. Roush ran a Maverick back in the day for that reason. If I wanted a little stiffer body I would go with a 1984 - 86 SVO and fill the engine bay.

Take your time and the engine will come to you. Never believe anyone when they tell you an engine is completely rebuilt.

 
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