The elusive 224/3.7 MerCruiser banger

Here's a link to some picture of the two with intake pictures.
NOS FORD MOTORSPORT B460 HEADS & INTAKE | 460 Ford Forum

 

It was a block, pistons and head change. Parts were salvaged from the first engine. The first shop screwed up trying to bore it 30 over so it was reboredanother 10 (free) and I chose 40 over low compression pistons. then a second shop milled the head flat and something went wrong and he had to do it twice reducing the head volume. The final cranking compression is now 150 psi after running it two hrs. The earlier engine had 170 cranking pressure so it is not the 135 that I planned on for using a supercharger but with the extra ignition advance it feels so much better I may leave it as it is.

Feelings are subjective but I had become used to the smaller 2.5 engine and there is absolutely no comparison in how the two feel. The 3.7 is more trouble, but it is certainly worth it.

 

I have blasted blocks before but always done them before they go in for machining so the re-builders do a flush on them, then I will follow on with a gallery flush as well. If you plan to paint the block this really works well, you just have to be extra diligent on getting rid of left over abrasive. Also, if you use an epoxy primer and 2k paint and the block will look new for years.
With this 470 I am doing I want to obscure it origins so am in the same boat. (pun) preferring to put the block into bare metal and maybe clear powder coat it to keep the finish bright, however just got a quote back from an industrial stripper at $450 per block - and I am doing 2 (always have plan B). That is nuts. So I am checking out CO2 blasting, Has anyone else done CO2 blasting to one of these blocks to see how resistant they are ?

 

Sean, just clean the block, prime it and paint it. I painted one orange a decade ago and it is still orange .
Go thin on the paint or it will block heat conduction. If you want to obscure the make of engine, flat black helps. And the inevitable paint damage will not show with the mercury black beneath the finish paint. mill off "Mercruiser" from the valve cover and the side cover. Or use bondo there.
You could use a ford valve cover but the Mercruiser valve cover is less known and may be a better choice. Or screw the "hood" shut with 58 screws like I did, that will inhibit down the casual tire kickers. I tossed him a screwdriver and said he had to put them all back too... best to get a deposit of $50 to begin with so he has incentive to put them back. ( It had no hood but most of the body that would have had to be removed to see the engine. Otherwise they could only see through a small opening I left to get at the carburetor.

 

How long are the pushrods?

Need to order pushrod length checkers.

My build is a Johnny Cash Cadillac, one piece at a time, did not start with a complete engine.

 

That would depend on several things. What head do you have? My push rod are 8.5 on the intakes and 10.250 on the exhaust, 3/8 dia. I have a Boss head.

 

I have an Edelbrock head, so I would assume close to stock length.

 

Push rods should be the last to buy. Different heads, block decking, head surfacing, head gasket thickness, cam base circle on the cam, lifters and rocker arms type all play into push rod length.

 

I want to order pushrod length checkers.....

 

Never mind, I just found some pushrods in another box of parts.

Appears to be 8.615" to 8.620"

 

The cam grind makes a big difference and as flatrod wrote do the pushrods late in your work.
They are cheap so you can try different lengths.

melling lengths and pushrod numbers:
6.776" #584
6.886 #404
7.513 #594
7.645 #444
7.800 #314
7.800 #1004
7.894 #614
7.900 #1014
7.950 #1024
8.000 #1034
8.144 #394
8.182 #664
8.408 #424
8.492 #434
8.555 #324
8.693 #574
9.130 #274
9.295 #334

the lengths are further subdivided by paint code
for a melling #274
red code is short 1mm
no code is stock length
blue code is long 1mm

There is a variety of ends on the pushrods, be sure they fit what you have.

I looked through a catalog for the ends that fit my stock lifters and stock rocker arms and made the list. Depending on your rocker arms, none of the above may work


If the pushrods are straight, they are stronger, so I made a gauge to measure how far they are crooked and returned 80% of those I bought. I still accumulated boxes and boxes of pushrods. I have a measurement for mine that is a little different from yours #324 fits a measurement for mine

 

I fully intend to order made-to-order pushrods from Manton.

I just wanted to know the OEM length so I could order a pair of pushrod length checkers so I can set everything up and correct the rocker arm geometry.

Something like these.....

https://www.jegs.com/i/COMP-Cams/249/7902-1/10002/-1

 

It looks like the Jegs part will fit the Bill for what you want to do. I am a cheap prick and just cut a stock one in haft, threaded the ends and put a piece of all thread between them. Works well but don't try to open the spring unless you have test springs on. I buy my push rods from Smith Brothers. They keep lengths in .050 increments. And just a note, if you have guide plates, harden ends are needed.

 

The jeggs part has the right size balls on its ends and as it is long, you can cut the female half shorter if you need to.

 

Speedmaster head still hasn't gone on sale.

What are the odds they do a labor day sale and it's included?

What are the odds they jack prices across the board before whenever the next time it goes on sale are?

$500 for a bare head that isn't even a "special" casting just seems insane.

 

It is even worse that new iron heads are not much cheaper than that.
But it is not all bad as entire engines needing rebuilding are cheap. I've paid between $100 and $300 for them. I bought a worn out Iron head for $75, paid to have the intake valve guides done (I don't remember the cost of that) and there was other work done $150 to surface the head as its size made it hard to mount in his machine and when it was done I had around $350 into it and I regretted not having bought a new aluminum head to begin with.
I saw new bare, unmachined,Kaase P51 aluminum heads on Ebay( a couple years ago)for a little over $400 there were only a couple of them. They were worth that but I did not buy any.

Don't "panic buy". Look around , keep your eyes open and enjoy the search.

 

arse
I have been in the auto parts business since the 70's and the performance parts business since the 90's.
The last 2 years have been brutal to the industry.
My business is down 50%.
A lot of the parts are made in Taiwan & China and the supply/delivery has been cut drastically.
Shipping costs have doubled, tripled and more on shipping containers.
I get price increases each month and expect many more.
I am lucky to make 7-10% on $300 items right now.
Any discounts you see are on high margin items that they have a large inventory of.
Parts you paid $100 for now cost $150, so you do not have the funds to replace them.
CNC shops, laser shops and foundries are drying up.
Inflation is making your money more worthless every day.
My theory is buy it while you can afford it cuz it may never be available again..........

Jeff

 

Looking for cam grind recommendations for my mild build, I have a big chamber Pro Comp head, flat top pistons, a factory 4 bbl intake and shorty header for exhaust in a Model A pickup. My build got put on hold for a while, been reading through the topic again trying to catch up.
Thanks John

 

I just posted some free Mercruiser parts in the "pay it forward" section.

 

http://www.sdsefi.com/meltdown.htm
I just read this and reccomend it.
It is about compression ratio, power output etc.

 

I don't quite know where that section is.
If anyone is looking for stock iron cylinder head cores. I have 3. They are free. The buyer pays shipping or pickup near St. Louis.

 

Doing aMercruiser engine on the cheap for a manual transmission:
I have previously paid $100 to machine the crankshaft end for the pilot bushing.
There is the option of doing it yourself. I chose to do it with the engine partly assembled( head, pistons and connecting rods removed) as I am working on a low time oiltight engine and I want to use the seals that are now in it as the little straight block seals are hard to find.
this is the sequence I'm following:
1. if the flywheel is the new style one, replace it with the old style one which is a Ford car flywheel.
2. Scrape the paint from the friction area of the flywheel
3. bolt a piece of angle iron across the block.
a. bolt it at only one end so its distance from the crankshaft hole is adjustable.
b. locate the other end with a c clamp to a 6" scrap of flat 1/8 metal which is bolted to the block at its upper end.
c. clean the crankshaft center hole with sandpaper.
d. gently clamp a test indicator to the angle iron so that its probe is in position to ride on the crank center hole.
e. carefully adjust the end clamp on the angle iron so that the test indicator is in the middle of its range.
f. rotate the flywheel by hand while watching the test indicator.
4. The crankshaft centerhole was true so it is time to drill it with a Milwaukee magdrill held centered on the flywheel face with its magnet. Magdrills are heavy so position it accurately before turning on the magnet.
The magdrill is available at tool rental outlets.
They heard that I only wanted to drill one hole and at their place so the boss said there would be no charge.
The other DIY option is to put the crankshaft in a lathe with the crankshafts flywheel end mounted in a steadyrest.

 

I routinely remove paint from the steel flywheel clutch disk friction surface. It can be scraped off. It is a hard very tough paint and scraping it off is possible on flat surfaces. The best tool that I have found for that is the sharp side of a very flexible steel drywall applying trowel.
It is held in both hands and flexed into a curve. Drag it across the paint to remove a strip of paint. This works on steel but aluminum is more difficult as it is so easy to gouge. A sharp chisel may work but its corners will leave gouges in the metal. That is why I use a thin steel blade bent into a curve to avoid gouges.
Mercruiser paint is very durable, the result is not worth the effort needed to remove it. If a different color is wanted, spray it over the black.

 

I use a very conservative cam which worked out quite well. It produces more torque in the normal operating range and does not let the engine detonate. I wrote about it earlier in this forum (or whatever it is.) With low compression pistons and a vacuum advance I run more ignition timing with good results (more torque). I may give away some at the top end but I got much more than I gave. Run a car cam, with 115 lobe centers you will be happier not using a boat cam assuming this is a street application.

 

Waiting for a "mag." drill. I designed a fixture to bolt a 7" Harbor Freight angle grinder onto the flywheel so I can cut 5/8" off the end of the block.
(Beck suggested this method)
the dimensions are metric as it is easier to avoid mistakes.
Basically your fixture is a fabricated "U" shape built up of 1/4 " 3/16" or 1/8"steel bolted between the flywheel and the grinder. For the grinder to fit remove its handle and put the handle on upside down.
For a deep enough cut you will need a 7" angle grinder and an abrasive disk with a dished center. Those with built in center nuts will allow the abrasive cutoff disk to pass over what it is cutting. I have a German disk "Pferd"(horse) brand. There were no aluminum cutting disks in the configuration I wanted so I was told to oil it with WD40 and it will not plug up.
I will tell you if the lubricant works.

Dimensions:
base plate:
Thickness 1/4"(stiffer) or 1/8"(allows deeper cut on flange)
Width 100mm ( grinder width between its mounting bolts)
Length your choice around 250mm
side plates :
they can extend beyond the base plate as long as they do not interfere with the aluminum being cut. It may be necessary to cut away the aluminum flange in short sections to prevent interference.
Width(wider is stiffer) .
Height an inch or so above the mounting hole for the grinder.

grinder mounting bolt holes are:
50mm above the base plate (bottom of the "U")
40mm away from the grinder arbor
69mm from the flywheel teeth

bolt holes or slots to mount fixture to flywheel:
71 mm edge to edge between them
3/8" diameter
24mm to edge of flywheel and 44mm to edge of cutoff wheel

This may save trips to a machine shop but be careful as it is an untried experiment. These dimensions are my best estimates. Check carefully before cutting to see if they work for you. Push the cutoff wheel into the aluminum with the cutting side of the wheel moving upward so it can't climb on top and go crazy.
All of this is dangerous, protect your vital parts.

 

Dennis,
A couple of pictures would help.

 

Once you're "done" cutting swap on a new wheel and do a finish pass.

 

I don't understand cutting 5/8 off the block. There appears to be different blocks in this area. I have 4 engines now, one running, all of mine are the same. I had to put a pilot hole in the crank and then everything bolted up like a factory chevy set up. I know Gearheads has a block with smaller bolt holes, at least I think that is what he said. Others have reported 1/2 dowels, all of mine are 5/8 dowels, but are really tight where I had to ream the the bellhousing to get it to fit. If I would of cut off 5/8 of the block, I would be making a spacer, or have a ruined that block. I say check first before you just whack it off.

edit
Looking at my blocks 3 have 1/2 starter bolt holes and the one with a starter on it has 3/8 bolts.

 

Flatrod,
I agree, mock up and measure everything before you cut the block. I believe that the need for that modification is dependent on the input shaft length of the transmission. I'm planning to run a T5 with the Jeep case and input shaft. I also have a T5 from a Camaro which has a different input.

I've also seen at least two variations for mounting the starter. One of my blocks has threaded hole and one does not.
Measure, measure, measure!!!!

 

My T5 is the T5Z Ford trans, but I put all the guts into a GM case,(Camaro T5). The Ford and the S10 T5 have the same case to input tip length, but different splines. And it is the same lenght for the T56 and the Muncie I have. I went with the GM case so I didn't have to use any adaptor's.