Technical 4 cylinder mercruiser-engined cars

I had a problem with .060 on a 153. It started seeping water after about six months. They problems with core shift on some of those engines.
Norm

 

The advantage of using V8 pistons is that there are more performance choices. Not as many for the 283 as there used to be but there are still some sitting around. Something I found is that over size replacement pistons are shorter than advertised or stock pistons so that the over bore does not boost compression in a standard rebuild. Or it may be to compensate for cleaning up the head and block. At least every set of .040 over pistons I tried for this build were shorter that the advertised CH listed.
Core shift is a problem with the 194-292 sixes. The most consistent castings are the Mexican blocks. One easy check is to examine the water pump cut on #1 cylinder. It should be centered and even from top to bottom. I would imagine the same goes for the fours.

 

Six Ball, since I have my new CNC mill this stuff is staying here in my shop!

 

WOOPEE! That is good to hear. When I grow up I'm going to get me some of that.

 

What are the rod specs 153 vs 181 big end, length, and pin diameters? Looking at the opposite of you Sixball, 181 with 153 crank. Half of a 327 essentially.

 

The rods are the same length and have the same piston pin size. The difference is the big end. The 153 crank pin is 2.0 and the 181 is 2.1. they use the same rod bearings as the 2.0 & 2.1 small blocks. The piston CH is different. The 151 has a 3.0 inch stroke and a little longer rod. I read about putting a 181 crank in a 151 so if the rear seals match (1 or 2 piece) that can be done too. he rods are the same as the small blocks too except the big end is narrower. I think the forgings are the same but the V8 rods have one side ground so they can sit side by side on the crank pin. 151, 153, & 181 all use the same main bearings except the N code 151.
So if you put a 153 crank in a 181 use the 153 rods and probably 327 pistons. Not sure.

 

I have both 153 and 181 "core" engines. The 181 had two freeze cracks in the crankcase My 153 seemed in better shape so I left it at the shop. I sealed the 181 cracks with green locktite and then stitched them by drilling and tapping 1/4" cap screws along the crack and embedded the crack and screws in jbweld. So it is probably time to swap blocks at the shop.
As far as wall thickness goes, they all get thinner after rusting. but looking down at them through the deck, they seemed to be about 1/2" thick walls at the top.

 

Summit sells an 0.080 oversize chevy marine piston in sets of 4 but I don't see rings for it. It looks as if it is intended for the 153.

 

My 470 had been bored 0.030 but that did not leave much only about 1/8" of cast iron and another 1/8" of cast aluminum. The carb dribbled into cylinder 4 and it burst. I see 0.060 boring mentioned on a couple engines but it seems a very bad idea. Mahle does sell a sleeve which will fit right into an 0.030 oversize 470. Although one would then have to run 4" pistons, it seems a way to save a block.

 

What you say makes great sense concerning pits that do not come out, core shift would require sleeving which is where that cylinder is headed anyway. As you are in Portland, Rick's Cylinder Head Service, in Oregon City, is first rate. They treated me so very well, absolutely wonderful.

 

Those of you trying to buy forklift engine parts need the following information to tell the parts counter guy :

Hyster used the gmc 153 engine in older warehouse forklift models S40XL through S60XL the serial number began A187______

Hyster used the GMC 181 engine in newer forklifts S40XL through S60XL
their serial numbers began B187_______ there was some change about 1995 but I do not know much about it except that the water pump and some other things were different.

 

Here's one I spotted at Shades.

 

Gents, I am building a Willys M38 with my daughter (with the end result being hers) and have grabbed a couple of Merc 4s. One was a 120 HP donor engine with a weepy freeze crack. It has a good head and other parts. The other is an older 110 HP which I imagine is the same block and all with a different cam/carb? Anyway, the block is mint on the older engine and it's my plan to use it in front of a TH350 with the Dana 18 hanging off the back. This will be a stock height rig so hopefully the SHORT driveshaft has shallow angles.

And now to the crux of the matter. The older engine has a forged crank and the newer engine has a cast crank. The counterweights on the forged crank are noticeably smaller, but I'd imagine it's a stronger crank? Given the choice, which would you use?

 

Sorry I can't answer the crank question but be sure to replace the cam with one designed for automotive use. When you talk about different cranks any chance you have one 153 and one 181 cubic inch engine?

Charlie Stephens

 

No, unfortunately no 181 in the mix. I figure the cast crank was a cost-saving measure. The forged crank engine was, I believe, a 60's boat. The valve cover said 110 HP

 

Just a guess but maybe passenger car versus industrial/boat? I didn't notice if the crank was cast or forged but my 181 Mercruiser sure had a much heavier crank than the 153.

Charlie Stephens

 

Some 181 cranks are fully counterweighted and some 153 are not, so that could explain some of the weight difference as well as forged vs. cast.

 

I'll try and get some pictures. I have a 181 and 153 on the bench now. There are other 153 cranks around.

 

Thanks Charlie, following your advice, I had my cam reground. I had a Crower cam in a chevy 350 I liked the cam and I used that profile on both of my mercruiser engines. Much nicer than boat cams.

 

cam timing adjustment to advance or retard the cam timing:

I could not find an offset key to purchase so I taught myself to mill a hardware store key to make a 1 degree offset key.
1. lever out the old key with strong sidecutters
2. mill a metal block with parallel ends and a thickness less than the key's height. Use it for a setup jig in your milling vise so the key is clamped flat for milling.
3. mill a 3/4" x 1/4" thick key down to a thickness of 0.200"
4. mill the key to a height matching the stock key.
5. mill the thickness of the key down 11 thousandths on the side of its convex end
( a depth jig will help position it.)
6. turn the key over and using the vise jaw to position it mill the side of flat end down 11 thousandths. clean up the key with a very small file and make any minor needed thickness adjustment. A thickness of 189 thousandths was what I needed.
(note: I wrongly posted that the key was 7/8" although they can be made to fit by milling the height down it is much easier to use a 3/4" key)

 

yes I have one of each. Although the cranks look similar, the journal size is different.
dennis

 

The rod journals are different but the mains are the same.

 

On VW air cooled we shimmed the crank gear out, or milled a little off the back to advance or retard the cam. I don't know why it would not work on a Chevy 2 motor. JMTW Frank

 

There is a timing set that has 3 slots in the crank gear. I'm not sure how much advance or retard each gives.

 

How about an IH slant 4? These engines are basically half of a 392 V8. These are good little engines, they run strong, and IH engines are very well engineered and built heavy duty.

http://www.ebay.com/itm/IH-Navistar...m4ac54f2cc4:m:mlhyLJ-eC_OKT8n9aLqyr9Q&vxp=mtr

 

Not sure what the older engines used for fuel delivery, but I am pretty sure if you can't find someone to give you a four banger out of an S-10 or mid 80's Camaro/Firebird for free, you aren't trying hard enough.....

 

Those GM 4 cyl. are great motors whether it be the Mercruiser, Iron Duke or Chevy Nova 153 like I ran in my Willys. In fact we are putting another Iron Duke in a 39 Willys PU and I have a Super Duty Pontiac 4 cyl I'm looking for a body to put it in.

Pat

 

In answer to your question I think a vertical in line 4 looks better than a slant engine, just my preference. What is the choice of transmissions for this engine and what do they cost? The 181 uses a Chevy bell housing which means many of the GM transmissions will bolt right up to it. You can get a standard speed shop adapter to use an early Ford V8 transmission (which is what I am running in my AVATAR). Where can you get parts (especially if you are on the road)? Who knows how to work on them? What is the cost of parts compared to a GM engine with production in the millions (because many of the parts are common with the SBC V8). Is the existing cam useable or is it fine tuned to run as an industrial engine at one small RPM range and not good for use in a car? Is it worth all of the hassle for an additional 15 cubic inches? Maybe my concerns aren’t valid and are just based on my lack of knowledge about these engines; it might be a great engine.


Charlie Stephens

 

These engines were used in many IH Scout's. They run very good on-road. Check in with the Scout dudes, these engines are legendary, will kick a Chevy's ass. They typically were mated to a Borg Warner T-18 4-speed trans. These trans were designed for heavy duty for truck applications, and were also used by Ford and Jeep. The availability is actually quite good for these. And the top loader design makes for an easy installation. Together you're talking about a hell for stout power train.

IH also used Torqueflight transmissions, if you prefer an automatic.

Parts for either engine or trans is actually very good, your local IH dealership, which just about every small town anywhere in the country has one, can get the hard parts. Electrical parts, starters, alternators, spark plugs, points, condensor, rotor, cap, etc, & carbs, are readily available at any auto parts store. They're just ordinary parts used by countless other auto mfgr's, nothing special. AC Delco, Holley, etc. Who knows how to work on them? Uhmmm, that'd be you dude. We are talking hot rods, aren't we? You can turn a wrench?

I'm not trying to talk you out of the GM engine, if that's what you want. I thought the point of the thread was to discuss available 4 cyl engines that were possible choices for use in a hot rod. Here's a great running engine, w/ cross flow head, built incredibly stout, reliable as an anvil and will out last you and your children, and is something different.

 

The Scout engine is worth considering and certainly the crossflow head makes constructing manifolds much easier. In my case I wanted an inexpensive(that aspect never does work out) engine which is narrow, short so it can be snugged in behind my I beam axle and which bolts to a chevy bellhousing already in my car .
So it was a little mercruiser.