Mercury 410 Build

[Porkchop]

I started to doubt what I had after you all pointed out the high piston to deck clearance that I have (~0.032"). But all of my parts were off to the machine shop before I even started this thread so I haven't been able to quickly get info or measure things.



I am looking through 2 books - one by George Reid and one by Pat Ganahl - to better understand what I have.

One book shows the 410 had a piston to deck clearance of 0.005", one states 0.015".

I have a 1U crank - one book states this only came in a 428, the other doesn't say one way or the other. I guess this is a moot point, just interesting.

The rods have a casting number of C6AE-C. Neither book lists these rods. Anyone familiar with these and what their length is?

The shop is going to install the crank and measure stroke and piston to deck clearance anyway.

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!

The heads were fully machined before the first build so they are square. Don't know exactly how much was taken off, but I did measure the chamber volume.

So to confirm, you're recommending decking the block to get to whatever will achieve 10:1 and using the SAME cam I already have?

Thanks for all the input!

[My427stang]

Recommend is a hard word, LOL, but sometimes we have to do what we have to do, it'd makea nice driver and nothing is out of line here for a decent build.

Stock blocks always need to be cut, if you leaned on that one, it may be .020 in some places, but they are always crooked...make sure the machinist can square it up.  Use a .041 head gasket, and end up .015 below deck, it'd be decent for quench, and likely get you ate close to 10:1, I wouldn't go over.  You need to get a real number for the chambers and deck height though if you don't have it, and check both heads, they tend to be crooked too

After that, assuming you are stuck with the cam, retarding the SAME cam 4 degrees, to a 112 ICL, would get you in the ball park.  It seems odd for a small cam to be retarded, and don't think I am telling you the cam is junk, but it is v ery short seat to seat.    If you use it, and retard the cam, what you are really building here would be a blueprinted 416 inch "poor man CJ".  The CJ cam actually was retarded even more and had slightly more LSA, but it also had a few more cubes

It'd be a nice driver and plenty more power than an old 390 or 360, but it won't have a lot of cam sound at 49 degrees overlap. 

3 things though, and I probably would not build it without.  1 - headers and a dual exhaust with a crossover will help greatly, especially in a truck, 2 - have the distributor recurved, makes all the difference in drivability and part throttle, 3 - can the stock 4 barrel now and get an RPM intake or even a Streetmaster. 

C6AE-C are 6.49, although I guess the correct number is 6.488 by some sources.  If big bolt, would be a PI rods, but if 3/8 bolt, relatively common 390 rod, and fine for what you are doing

[Porkchop]

The method I used for measuring the head chambers was to stick a piece of acrylic to the head with grease and then fill the chamber with water through a hole in the acrylic (using a dropper with markings every .25-.5CC if I recall). I repeated the measurement over multiple chambers, and they all came out to right at 74CC. I personally felt confident in this method, would you say this method is accurate?

If you were to change the cam, what would you change it to and would there be other things you'd consequently also change along with it? I am not 100% set on that cam, but of course having an already broken in and paid for cam is very appealing.

[DuckRyder]

Edit: RE: the books, i don't know that anyone ever cataloged the errors but many years ago on TOF it was believed that there were some errors in specs in this books that got recycled to other books. I tend to trust Barrys book and the Steve Christ book the most.


RE: the measurement, that's pretty standard procedure. My only concern is if you're refilling the dropper multiple times there's potential for inaccuracies there. SOP is a graduated burette. I personally would be concerned if my numbers came out way off expected or very uneven.

I don't have much else to add here but voice of experience.

Change the cam now if it is borderline for compression.

Ross or Brent or probably a few others can work from your numbers to grind a cam that will work better if it is needed.

[My427stang]

The method I used for measuring the head chambers was to stick a piece of acrylic to the head with grease and then fill the chamber with water through a hole in the acrylic (using a dropper with markings every .25-.5CC if I recall). I repeated the measurement over multiple chambers, and they all came out to right at 74CC. I personally felt confident in this method, would you say this method is accurate?

If you were to change the cam, what would you change it to and would there be other things you'd consequently also change along with it? I am not 100% set on that cam, but of course having an already broken in and paid for cam is very appealing.

Your method seems accurate if the dropper worked as it should, and since it was so repeatable, it sounds it.

I'd prefer to see you in a custom grind, something like 278-280 adv intake, and 10 degrees more exhaust or so  However, would need to know more about the truck, use and fuel to lock it in. 

Your cam really should do fine though at 112 if you ran a 1020 gasket and if the square deck allows it to stay at .015 below.  On the high side of decent quench but manageable compression. If it needs to be cut more, then likely need to address it.  Just as a public service announcement, this is why cam/heads first, compression second.  Hard to back into use when hobbled by a compression number.  That being said, you aren't far off, you are in a different boat than Duck

However, again, you need to really address intake and exhaust if you want to make some power.  Exhaust and intake cost could easily be in the 50 HP range, even with a mild motor

[Porkchop]

The truck is a 69 F100, 2wd, 3 speed manual. No towing or heaving hauling, just basic homeowner stuff on occasion. No drag racing. A fun street / hot rod that can and will be driven anywhere (no real expressway driving and no salt/winter). It will be "abused" - for lack of a better word - on occasion.

I'm okay with running mid grade to premium pump gas.

Given all of your guys' recommendations, I am committed to upgrading the intake and exhaust manifolds. I have an intake, but I have not yet bought headers. It already has dual 2.5" exhaust, but no crossover. I will consider adding that as I will have to modify the exhaust anyway for headers.

I am also leaning toward changing the cam as recommended.

I calculate 9.83:1 if I go with some of the recommendations here. Like I said, I'm having the machine shop measure the piston/deck clearance so I will have a more true number.

Bore (in)   4.08
Stroke (in)   3.98
Cylinder Vol (cuin)   52.03
Pist to Deck Clearance (in)   0.015
Clearance Vol (cuin)   0.20
Gasket Dia (in)   4.33
Gasket Thickness   0.041
Gasket Volume    0.60
Pist Comp Height (in)   1.66
Pist Volume (cc)   9.50
Pist Volume (cuin)   0.58
Combust Cham cc   74.00
Combust Cham (cuin)   4.52
Swept Volume (cuin)   52.03
Compressed Volume (cuin)   5.90
Compression Ratio   9.83

[My427stang]

It'd be nice to get you into a hydraulic roller to avoid break in issues, but as you source a cam, be sure to think about valve clearance.

Last Speedpro motor I did had inconsistent valve reliefs and with CJ valves, radial valve clearance was good, but very tight.  In fact, I try to avoid those pistons, but when you do assembly, recommend mock up on both sides before final assembly to check valve clearance. We actually had to pair each head to a side for slightly more room.

[Porkchop]

Hello everyone.

I finally got the machine work done, and I am starting the reassembly.

This is what was done by the shop:
-Honed cylinders with plates (had previously been bored 0.030")
-Crank fully ground and bearing clearances set
-Crank balanced
-Block decked, pistons are 0.012" below deck
-Aluminum intake machined to fit
-New cam bearings

I was planning to reuse my original cam shaft and lifters. I noticed this copper colored spot on my cam that I previously overlooked. I can not feel this spot. I've included a picture of the mating lifter.

I've also included some other pictures of the wear patterns on the cam lobes.

As a reminder, this is my second time building this engine. I had a rod bearing failure. I believe it was caused by lack of oiling mods, bearing clearances too tighten, and lack of cleanliness.

Is it possible that this copper is from the failed bearing? There certainly was copper in the oil. But I would think I would be able to feel it.

Thanks for any advice.

[My427stang]

I would have to guess it was a piece of bearing smudged into that low point.

Will it be OK? My gut tells me lots of crazy stuff will live and that it is likely not on the path of the lifter for now.  However, I'd probably scratch at it lightly ot use a scotch brite pad or emory cloth to see if it comes off.  An iron cam doesn't have copper in it, and I doubt even with heat and pressure dissimilar metals would have fused permanently

Would I run it on a customer's engine, absolutely not, would I in a temporary engine or something I had to get moving?  Probably if it polished off

FYI - the oiling mods likely didn't cause your issue, but the other 2 reasons are very solid.  A high RPM engine can benefit from the mods, but honestly, 90% of the street FE builds wouldn't know the difference.  Be super clean this time, brushes, rifle barrel cleaner, pressure washer, whatever it takes

[Porkchop]

I believe it was copper from the bearings. With a light touch from scotch brite, it came right off. First picture is the same spot on the same lobe.

The following pictures are of the rest of the same lobe. Any thoughts on those wear pattern? All the lobes look similar.

I agree on the cleanliness. I hand washed the block on 4 separate occasions using bottle brushes on a drill in every oil passage and bolt hole. Every cleaning was finished by blowing off the whole block and every passage with compressed air.



 

[My427stang]

Looks like a normal pattern to me, lifter is offset to spin and as weight increases at max lift the wear usually evens out.

I'd love to see you go modern hyd roller, but nothing there seems scary to me

[Porkchop]

I have been working on this slowly as time allows. The short block is assembled, and I was checking piston to valve clearance.

Unfortunately, it looks like I have an issue with the intake valve.

-Crank gear set at 4 degrees retarded. In theory this is 112 degree intake centerline. I actually measure about 111.5 degrees, so within error.
-Using old head gasket for measurement. Thickness is 0.045". Just snugged head bolts
-Using checking springs with hyd flat lifters that are pumped up
-Intake valve is 2.09"
-Pistons are Silvolite 1139P
-Block was decked so pistons are 0.012" down according to machinist.

Hopefully pictures show the edge contact of the valve in the relief in the piston. It's the shiny spot. I repeated the process twice on the same cylinder, the pictures show each attempt.

Are there any suggestions/recommendations?

Thanks again for the advice and knowledge that is provided by this forum/members like this.