Inliners International Forums General Discussion Engines GM 4 cylinders 151 153 181

I think mopar performance also sells a new 4cyl that uses the new hemi head. I saw one in a mag in some LSR car that George Poteet paid to have built.

I looked at a really cool Quad 4 today! A lot of great after-market goodies and a custom built 3-2 manifold, It is set up for, and has, a Camero T5. I'll try to get back and get some pictures.

Look at these pages for Quad 4 info and parts, http://www.angelfire.com/il2/insig2/quad4r.html , http://quad4rods.com/ ,

Much better designed engine than any iron Duke IMO.


MBHD

Nostalgia styling would call for an Iron Duke or a 153/181, cute styling would be captured by the Quad 4, but for overall power the Ecotec leads the way. I'm glad I don't have to run against this dragster. http://www.youtube.com/watch?v=xY6tMOfZhIs

I think I'll be happy building the 153 for my roadster, But if not there is plenty of room to grow. I won't be racing that dragster either! Beater

I second Jalopy's recommendation of http://quad4rods.com/. They have some neat stuff and John Ehrlich is a great guy.

will6er

How close will the left header for a small block come to fitting the 5 port head for a 153?

As close as a BB Chevy is to a Briggs and Stratton.

I wonder how it would be to go the other direction and destroke a 181 using a 153 crank. 4X3.25 would be, basically, half a 327, a little easier on the vibrations and a bit quicker reving.

That's a thought. Just thinking of building a header. I need to wait till I get the 153 home. I think the L6 flange plates sold on ebay may be the easy way to go. The front 3 cylinders and the back one should work well. I'll know soon.

Here's my zoomies on 5 port heads,.there is divider plates on the backside and the flanges are made with a file, hole saw and drill press and taps. ,

>the flanges are made with a file, hole saw and drill press and taps.<

That is the way many of us do it. Another approach is to contact Tim Tenold, here on the site. Tim can cut flanges.

I brought the 153 home yesterday. I picked it up in Reno. The old pickup likes it a lot better than the Big Dodge! Dave and I were able to slide it into the bed on two 2X4s! It is going to be fun to work on.

Beater

Here is a link to a lengthy GM 4 cylinder thread on the H.A.M.B. . All of the information is not 100% correct , like here , but there is some good stuff. There's also an Ansen head if the guy still has it.
Checking out the 153 I see that it has no harmonic balancer just a hub and pulley. It seems a balancer would help but which one? 230? SBC? For the 5 port head it looks like a V8 header is pretty close. At least less welding than building one from scratch. And there are a lot of them laying around.

Beater

After GM went out of production with the Iron Duke, they licensed the design to Kansas Racing Products KRP Website They make new block castiogs that can be had with bores up to 4.125" and that will accecpt v8 heads directly (block is drlled for head bolt pattern) They also have cam blanks and crank blanks and different stroke cranks. These engines were used mostly in midget racing. real expensive but looks like it would be bulletproof.
I would like to see one with a LS7 head the flows 400cfm, you would probably have to rev to 8500 rpm to make use of it.

Thanks Pete. The spin off from the 153 is amazing. 4.125 thats got to start looking like a 400 sb. Keep it coming. Beater

Pete, thanks for the link.

I've been looking for them since Speedweek (the guys that just upped the record I'm after tell me thye are running one of those blocks with a SB2 head on it, 350 HP, out of 2 Liters, on the dyno they claim ).

~179 MPH average. (record)

So now I need at least a 15 layer rated suit and a parachute.

Kinda cuts into the development budget, but if it was easy, everyone would be doing it.

Check with Arias, they had one (Iron Duke) in their showroom they were selling with a SBC head and one with a 392 Hemi head on it.

I pulled the head on the 153 today. It's .040 over. Quite a bit of soft carbon but there are still hone marks in the cylinders and no ridge. The piston is about .050. below the deck. The valves look good except for one intake that doesn't look like it is centered in the seat, but they are going anyway. It's looking like I'll only have to change the things I want to. The 181 crank is on the way.

2 things I can see Beater is that the 153 crank has a smaller mains if I rcall correctly than the 181, so are you going to turn down the mains or linebore the block? As for other heads the 153/181 valve order is E-I-I-E-E-I-I-E, and the SBC is E-I-I-E-E-I-I-E so the head can be adapted but it requirss a special ground cam ,not sure but I think 151p is the opposite.

the SBC is I-E-E-I-I-E-E-I

???

The mains are the same,only the rods are 2.00" on the 153 and 2.100 on the 181 crank.

Yes the mains are the same. I'm still working on rods, pistons, and crank grind to get the deck height I want. A small block exhaust gasket placed on the 153 head lines up fine with the ports. The bolt holes don't match. I'll get some pictures of gaskets to post. Beater

Would the 153 use the same dampeners as the 6s? It just has a hub and pulley now. Are the combustion chambers on the 153 head the same as the standard 6 cyl head? I'm thinking of using a comp 260H cam. It has a 1200-5200 rpm range. I am planning on using 1.60 exhaust valves and 1.85 0r 1.95 intakes. It's a street engine, what do you think? It's .040 over and will probably stay there.

The 4 cylinders dont have the same harmonic issues the 6's have, thats why many of them use a solid hub. So you will probably be just fine reusing it.

There is a lot of talk about vibration in the 4s. It may be due to fewer power strokes per revolution and not harmonics?

It's the firing order.
The harmonics are very different.

It seems that the two added pulses would smooth the engine as would 7&8. So, I should not bother with a balancer?

1,5,3,6,2,4 -L6
1,4,3,2 - L4

L4 engines above about 2.2 liters have a second order problem: http://en.wikipedia.org/wiki/L4_engine#Balance_and_smoothness

Thanks Panic, I'm having a hard time getting my head around this part.

"The reason for the piston's higher speed during the 180° rotation from mid-stroke through top-dead-centre, and back to mid-stroke, is that the minor contribution to the piston's up/down movement from the connecting rod's change of angle here has the same direction as the major contribution to the piston's up/down movement from the up/down movement of the crank pin. By contrast, during the 180° rotation from mid-stroke through bottom-dead-centre and back to mid-stroke, the minor contribution to the piston's up/down movement from the connecting rod's change of angle has the opposite direction of the major contribution to the piston's up/down movement from the up/down movement of the crank pin."
I see how the piston speed would vary at different degrees of crank rotation, but I really don't get why the piston would move faster in the top 180 than in the bottom 180. It is what it is whether I understand it or not.

Logic would seem to dictate that the piston is traveling at the same speed at both TDC and BDC which are the 2 apexes when the crankshaft reaches the end of it's stroke and the highest speeds would be at midstroke, either power or exhaust but some resistance would be realized on the compression stroke which would be overcome by the power stroke on the opposite firing piston. If the piston goes slower how long before it gets behind?

The highest piston speed is never at mid-stroke, it's where the rod beam is at 90° to the crankpin, at roughly 70-80° B/ATDC depending on the rod ratio (unless the ratio is infinite).
The exact point is easy to calculate using
sine of rod thrust angle = .5 ÷ R/S ratio (1.8, etc.)
1 Double-click your “Calculator” icon to open it
2 Click “View”, then “Scientific”
3 Input the result from the formula above
4 In the left margin of Calculator, look for the check-box that says “Inv” - check it
5 Make sure the box marked “Degrees” (not Radians) is checked
6 Click on “sin”
7 The rod thrust angle in degrees will show in the window
8 subtract 90 (you'll get a negative number, ignore it)
9 The result is the crank position for maximum piston speed
Example: 1.8:1 rod ratio
.5 ÷ 1.8 = .27778
arcsin .27778 = 16.13°
90 - 16.13 = 73.87° ATDC

Piston speeds around TDC and BDC are always different, except for exactly TDC & BDC, when they're stopped (assuming centered piston pin, and nothing else odd).
90° crank rotation has already done more than 50% of the stroke in all engines (57% in a 1.8:1 rod motor), so the motion around TDC is faster.

The highest piston speed is just before the oil pan slows them down.

Where is that on the calculator?? (V+M)~Ex2?? or some other such garbage :):):) From a technical point I can see the difference, but on a practical level what will it have to do with the average Joe building a street engine? ???

Yes, let's use "logic would seem to dictate", instead of "garbage".

"Logic would seem to dictate", I really like the sound of that and it's even fun to say. Yes, I'm for using that instead of "garbage". You'll be hearing a lot of "logic seems to dictates" from me hereafter.
The 181 crank came yesterday. I haven't had time to fully inspect it yet. It doesn't look like a big stroker crank but 3.60" is only 1.80" center to center right? Now, the 153 rods use the 2.0 bearings and the 181 rod journal is 2.1. Thats .100" to play with + .030 undersize bearing. So is that about another 1/8 stroke if the crank is ground off center? I'm confused. Beater

In this particular instance, "logic" was completely wrong, and "garbage" provided the only accurate explanation.

?

I added a bunch of pictures of 153 stuff. There are the 6cyl flanges I'm going to use on the 4 and some comparison of 4, 6, & 8 gaskets. Sorry i don't have a V8 head gasket but put the SBC head thoughts to rest just laying the 4 gasket on a head. There are some shots of the front sump pan and crank hub. Also the 181 crank in the lathe, and a peek at the aluminum cam gear. It uses an M-62 oil pump like the 6s. Notice the piston order. 1&4-2&3 move together. Firing order is 1-3-4-2. It just has ups and downs nothing extra to smooth things out. 153 pics Beater