Mercury 410 Build

[Porkchop]

Hello,
I am starting the process of rerebuilding a Mercury 410 engine. I already built this engine but unfortunately it lasted <500 miles before developing a rod knock on #4 connecting rod.

I do not know 100% why this happened, but I would say it was a combination of too small of bearing clearances, cleanliness, and oiling issues. Rod bearings had 0.0015” clearance and mains had 0.002”, I understand now this is too tight. And I did not do the oiling modifications.

This time I’ll be taking the block, crank, rods, etc to a machine shop that knows FE’s.

Application: 69 F100 with 3 speed manual. This is a street truck, I will not be racing, but I will have fun with it.

Expectations: I would like 400-450 hp. No, I am not dead set on this. I know that is borderline for some parts I may want to use and so perhaps I would back off of that expectation.

Engine Details:
-Original Mercury 410 block, crank, rods 
-Block is bored 0.030” over
-Stock Deck Height (pistons 0.030” down)
-Crank main and rod journals are 0.010” under
-Howard’s Cam HRCCL250031-12
https://www.competitionproducts.com/Howards-Cams-Hydraulic-Flat-Tappet-Camshaft-Lifter-Set-Ford-FE-352-428-213_223-050-525_525-112-LS/productinfo/HRCCL250031-12/
-Stock Rocker assemblies
-Sealed Power 1139P 9.5cc cast pistons
-C6AE-R Heads with CJ valves. No porting. Measured 74CC chambers
-Stock 4 barrel manifold (will probably go to aluminum)
-Edelbrock 750CFM carb
-Stock truck exhaust manifolds with dual exhaust. Will probably go to headers eventually
-Compression ratio estimated at 9.6 static, 7.9 dynamic

I want to keep the same block and crank. Perhaps I need to change pistons and rods to achieve my expectations?

Regarding machine work, I want to make sure I give the shop direction or I walk out knowing exactly what will happen before hand (this didn't happen with first shop). I think the crank needs to be reground to achieve the advised 0.0025-0.003" clearances. I think I will want to have the block 0 decked to increase compression a bit. I think the bores will be fine with a hone. 

What are the thoughts/opinions on this?

Thanks for any advice!

[blykins]

Need a little bigger cam, but 400-425 hp would be no problem.

[Tommy-T]

Installing headers on these old trucks is a dramatic performance upgrade. The stock exhaust manifolds are awful.
Do it now while you've got it torn down.
You won't regret it.

[DuckRyder]

Agree with Tommy, do the headers and exhaust. IIRC stock truck logs have a 2" outlet so it's suboptimal....

Flowmaster makes an 2.5 exhaust, and hooker may still be able to make a 2.25 that matches the hooker comp headers... not sure. Mines pretty much rusted away no thanks to jet hot.

I think the issue with the Flowmaster is you'll have to make connector pipes.

[Porkchop]

Ok, I will probably try to get headers on when I install the engine.

So should I stick with the factory rods and cast pistons?

What cam would be recommended?

[DuckRyder]

If it was me i would talk to Brent on the cam.

Depending on what you find id closely compare the cost of the machine work to a new rotating assembly.

Keep us up to date on the build, sounds like fun.

[Kevin66]

Just some thoughts for you to consider. Are you absolutely certain that your crankshaft is an actual 3.98" stroke 410/428 one, and not a 3.78" 390/406/427LR one? The reason I ask is because I have seen issues where people have installed replacement 410 pistons (with a 1.66" compression height) into 390 engines (which want a 1.76" compression height). This results in the engine having the .025"-.035" deck height you describe, which substantially lowers the compression ratio, down into the 8.X:1 range. That has a LARGE detrimental effect on the engine's power output.

I believe your estimation of both your static and dynamic compression ratios is off considerably, and it needs to be brought up. To achieve that, I really don't think you want to be cutting .030"+ off the deck surfaces! Unless you can find some actual high compression 420 pistons in .030" O/S, you may need to look at custom ones.

I agree completely with Brent Lykins' comment about the camshaft, if you do want horsepower up in the 425-450 range. He knows a lot more about cams than I do, but I suspect would advise going up about 10° @ .050" on both intake and exhaust. What you have now is essentially just a 'very mild' improvement on the stock 428CJ cam. These motors made about 400 HP from the factory, and that's with the CJ heads, 10.6:1 c.r., a very good factory intake and 735cfm Holley carb. It also had much better exhaust manifolds than your truck came with. So as several others have suggested here, get some actual headers for your truck. In that regard, Jay Brown found in his testing for his 'Great FE Intake Comparo' book, that an engine in the power range you're talking about (425 HP 428CJ) would 'average' about 330-336 HP with several different headers, and the ancient 'log' style exhaust manifolds, as found on most factory FE's, would only muster 293-296 HP.

And definitely replace that 83 Lb. cast iron intake manifold! Almost any aftermarket aluminum 4-Bbl intake you can find will deliver more power (as much as 35 HP!), and will take 50 Lbs off the front of your truck!

[driveamerican]

Does that cam really have the HO small block firing order?

[DuckRyder]

Those are SilvOLite pistons right?

Howards webpage is messed up i cant get it to give me anything, unless i back door into it from google.

https://www.howardscams.com/hydraulic-flat-tappet-camshaft-1963-1977-ford-352-428-1400-5200-howards-cams-250031-12

[Porkchop]

Sorry for the delayed response, I have been busy and not checked back.
 

Just some thoughts for you to consider. Are you absolutely certain that your crankshaft is an actual 3.98" stroke 410/428 one, and not a 3.78" 390/406/427LR one? The reason I ask is because I have seen issues where people have installed replacement 410 pistons (with a 1.66" compression height) into 390 engines (which want a 1.76" compression height). This results in the engine having the .025"-.035" deck height you describe, which substantially lowers the compression ratio, down into the 8.X:1 range. That has a LARGE detrimental effect on the engine's power output.

I did not personally measure the stroke. It has the 1U cast into it. I had it ground the first time, and I would have thought that this would have come up. Maybe that's not the case. Because of the damage to from the bearing issue, I have it at a shop being reground now, and I can inquire.


I thought that 0.030" was the factory piston depth for a 410. I am not sure where I read this now. Can anyone verify?

I believe your estimation of both your static and dynamic compression ratios is off considerably, and it needs to be brought up. To achieve that, I really don't think you want to be cutting .030"+ off the deck surfaces! Unless you can find some actual high compression 420 pistons in .030" O/S, you may need to look at custom ones.

I agree completely with Brent Lykins' comment about the camshaft, if you do want horsepower up in the 425-450 range. He knows a lot more about cams than I do, but I suspect would advise going up about 10° @ .050" on both intake and exhaust. What you have now is essentially just a 'very mild' improvement on the stock 428CJ cam. These motors made about 400 HP from the factory, and that's with the CJ heads, 10.6:1 c.r., a very good factory intake and 735cfm Holley carb. It also had much better exhaust manifolds than your truck came with. So as several others have suggested here, get some actual headers for your truck. In that regard, Jay Brown found in his testing for his 'Great FE Intake Comparo' book, that an engine in the power range you're talking about (425 HP 428CJ) would 'average' about 330-336 HP with several different headers, and the ancient 'log' style exhaust manifolds, as found on most factory FE's, would only muster 293-296 HP.

Understood about the camshaft. I chose it because I was concerned about detonation given the factory 410 is 10.5:1, and I didn't want to run premium (at a time when 87 was $4.30). In hindsight, I would be ok with premium or backing off timing when not.

Yes, I need to make headers a priority.

And definitely replace that 83 Lb. cast iron intake manifold! Almost any aftermarket aluminum 4-Bbl intake you can find will deliver more power (as much as 35 HP!), and will take 50 Lbs off the front of your truck!

I do actually have a knock off Edelbrock intake I am debating whether I'll use. It definitely needs some fitting.

[Porkchop]

Those are SilvOLite pistons right?

Howards webpage is messed up i cant get it to give me anything, unless i back door into it from google.

https://www.howardscams.com/hydraulic-flat-tappet-camshaft-1963-1977-ford-352-428-1400-5200-howards-cams-250031-12

Yes, SilvOLite. Original post is incorrect.

Howard's website was messed up some time, now it seems the link is working.

[DuckRyder]

I'm with Kevin66 here something seems wrong.

Silvolite list those pistons as 390 pistons with a 1.66 compression height. (so Truck/410 Pistons) but they should not be that far down in the cylinder with a 3.98 stroke crank. Investigation is in order.

Christ's book shows a 410 as .005 deck clearance.

[My427stang]

(3.98/2)+6.49+1.66=10.14

If he had an uncut deck or is eyeballing it, .030 is logical. I recently had 2 uncut CJ here that were above 10.170 too but you don't see it often

With your parts, I wouldn't deck it to zero, but if it hasn't been cut, I'd square deck to where it needs to be cut. At 10.150 you could run a 1020 gasket and be at .051 quench and 9.89:1 which is still easy on fuel, then I would cam up a bit to hit your numbers, that's a very mild cam.  it'll be nice to drive but you are leaving a lot of power on the table, more cam won't make it too rowdy

If stuck with the parts, don't worry though, that 10.150  decck combo will work, but I would install that cam at 110 centerline, no earlier, and depending on the   use, maybe even at 112.  That would make it behave very stock CJ like and would be a super nice driver on pump gas, probably not 400+ HP, but it'd be a nice runner

If I was playing with it, I'd likely go with an custom piston and cam, would need to know RPM range, gears, tires, intended use, etc, pick the cam first.  Cut the deck to minimum required, then get a dish that matches the compression of the new cam.  It would cost more, but you could get the most out of it, and as others said, likely end up at or above 10:1, tight quench and a cam that pulls hard in the area you most use it

I would not lose sleep over any of the combos, as long as willing to retard the cam but, be sure you check valve clearance on the cam you listed.  It is low lift, but a lot of the shelf pistons are tight on radial clearance, and those likely were not planned for the CJ valve

[Porkchop]

I did measure the depth. Looking back at my notes, I actually recorded 0.032". I found TDC with a dial indicator and then used a straight edge and feeler gauges. Maybe I was off by a couple thousandths in my measurements but not 25-30.

I did not have the deck machined at all during the first build, and I highly doubt it ever has been.

The purpose of the truck is a street/hot rod. I will not drag race, but I will be hard on it at times. I use it for truck duties around the house, but I am not frequently pulling trailers or heavy loads. 69 F100, ~29" tires, 3 speed manual, 3.25:1 rear.

[My427stang]

You likely were off but in the ballpark  Most uf use a deck bridge wth two indicators, you find the top then rock the piston to equalize the two reading and that's your true measurement

Uncut deck (10.170-ish) - your stack (10.140-ish) = .030 ish

Deck it square, and likely do the heads too, recalculate compression, and retard the cam to make it a little easier on pump fuel.  Did a temp 390 build for my F100 the same way with leftover parts and it was a veryr happy engine

...and good on you for actually measuring stuff, feeler gauges are hard to eliminate rock though

BTW, I think to meet your goals you need an Edelbrock RPM intake, cut the decks and heads to get closer to 10:1, then rock that cam back to 112. You'll be close or over 1 HP per cid, with the combo you have now, likely 375 hp ish.  However, in any case, more than any old F series came with!