New Member - and threw a rod

[Airportbum]

Yesterday I bought a 1966 Alpine. Checked out okay. Looks to be original and garaged its whole life. The same family owned it for all but two months of its life. The motor was rebuilt in 2009. Today on the way to the DMV to register, it sent a rod and other parts out the left side of the motor just in front of the starter.

My question is do I buy a new engine block from Sunbeam Specialties, or try to find a used one, or should I consider doing the V6? I was looking forward to driving this till winter, but life happens. It drove great for the first 24 hours. Of course, the tach, speedometer and horn didn't work - but it was still a lot of fun!

I will say that this is the easiest car I have ever pushed up on a trailer...

 

[loose_electron]

Depends if you want all original or are happy with resto-mod.

Before the engine went were you happy with the acceleration?

I personally have a V6, all new wiring, and modern speed-hut gauges.
That said, it still looks era correct and is very reliable.

 

[alpine_64]

Was the oil pressure gauge working? What did it read? Was there a ticking from the bottom end???

The motors can be susceptible to #3 main failure... But there are normally warning signs. How hard were you revving it?

 

[65beam]

Everything boils down to how soon do you want to have the car back on the road. The blocks from SS would be the fastest way to go since it would require swapping over parts and no machine work to the block if existing parts such as the cam, etc are OK. Machine work and parts would cost more than a new engine. A used engine in good shape and ready to install is rare so you may get into a lot of work, expense and time. Converting to the V6 is a lot of work and time. Some may disagree with me and tell you what all you should do to the new block before using but I've used a new block in the past and we checked clearances and found everything to be fine. It was a matter of putting everything together and installation. The Kid and I made the change in a week end.

 

[Airportbum]

I was doing somewhere between 60 and 70 on the highway. Tach doesn’t work. The oil pressure was about 20. No ticking that I heard. The coolant took off about 3 seconds before the bang.

I don’t mind the acceleration.

Are there any other parts I should be worried about in addition to the new block? What else should I change if I have the motor out?

 

[Ken Ellis]

Do you have an overdrive transmission? 70 is pretty revvy for a new-to-you engine with limited instrumentation.
But I don't want to exacerbate your grief... and sorry for your troubles.

I'd maybe do the short block from SS. $1400 and you're back on the road in a week, with a bit of summer left. That is, unless someone has a recently-pulled removed-running complete engine available, perhaps from a V6 swap... which is the path I took when it was time to refresh my original engine.

The V6 mod is pretty popular, is well-supported by advice and sourcing here, but there's still several months of parts-gathering needed to get all the bits together. I sense you'd rather be driving.

 

[65beam]

I was doing somewhere between 60 and 70 on the highway. Tach doesn’t work. The oil pressure was about 20. No ticking that I heard. The coolant took off about 3 seconds before the bang.

I don’t mind the acceleration.

Are there any other parts I should be worried about in addition to the new block? What else should I change if I have the motor out?

Replace the oil pump. There are articles in the TE/AE tech tips on how to check pump clearances. I have a couple new ones in stock and I found one had to have a little work done to it even with being new. Having owned the car for only one day you haven't been able to see what worked good and what didn't. Check the timing chain and gears, water pump, head and especially the oil pressure relief valve. Common sense will determine asking questions concerning status of a part. Check the bearing clearances of the new engine along with the clutch and flywheel .There are tips in the tech sections on this site and TE/AE that cover the typical problems. Oil pressure of 20 PSI is very low for road use. My engines run 45 to 50 PSI at highway speeds. There are tech tips for setting up an adjustable oil pressure relief valve. I have them on all of my 1725's. Again, if in doubt ask questions. If you're doing the change yourself take photos as you take it apart.

 

[alpine_64]

I was doing somewhere between 60 and 70 on the highway. Tach doesn’t work. The oil pressure was about 20.

20 psi at 60mph.. About 3800 is way to low.. The engine at minimum had issues with the reliefe valve, the pump or clearances... Would be sad if a stuck oprv lunched a decent motor.

At 3000 rpm warm you want minimum 30 psi.. And that's still not great... 45+ is healthy.

Check all clearances on the Nos blocks and iirc they only have low compression spec blocks left.. So you will be losing hp and performance unless you switch out pistons for the standard dish or flat tops to up the spec

 

[Airportbum]

Thank you for the comments. I’m glad to know I was probably the cause, and not necessarily a total lemon. I should have paid attention to the normal oil pressure.
My exuberance at finally getting one overcame my common sense on checking things out more thoroughly. Probably a mistake I will repeat in the future.

 

[todd reid]

Lots of good advice above. It boils down to how you plan to use the car and what you expect from it. Personally I would find 70 mph in a non-od Series V Alpine with a 4.22 rear pretty un-enjoyable after the first 5 miles, but there are things that can be done to improve the situation without resorting to a V6 (which I have done). One important point - make sure you thoroughly clean your oil cooler and lines if you reuse it. There can be metal bits in there that could damage your replacement engine.

 

[Hillman]

Don't know where you are. I do have a good 1725 that was in my burned SII that you can buy for a lot less than the SS new block. Also a SIII OD trans. It won't likely get to you soon and shipping depends on where you are. If interested, PM me.

 

[Alpine 1789]

Good advice all so far. One thing I would do before making the decision on new SS block vs trying to source a used engine is take a look at your head to see how much work it is going to need. Hopefully, the water jackets are in decent shape and the wear bars indicate that the head has a lot of life left. (We can help you evaluate the head if you take photos.) Money that needs to be invested in the head should also be factored into your overall new vs. used evaluation. Also, if you are going to stay stock but end up with a full engine rebuild, you should also take a look at some of the things that can be done to coax a little more out of the stock engine. Try searching "chevy rod" and "Vizard" to see what other have done.

Finally, be sure to browse the For Sale section here, as there have been a few 1725 engines listed over the past 6 months or so. Maybe one of more of them is still around.

 

[65beam]

Availability and time frame have a lot of bearing on what you do. Starting with an original untouched block lets you build the engine and also be able to repair with readily available parts if needed. Making mods such as chevy rods and other parts only adds to the cost now and possibly at a later date. Many shops won't make mods such as modifying the crank, rods,etc. due to a liability factor. The situation would be different if all stock internal parts weren't available.

 

[ChrisR]

Reading this thread got me looking closer at my pressure. Noticed it was less than 30 at 3000rpm and very low (less than 5) at idle.
Took the bypass valve out and it did not seem to move too smoothly. Left it in solvent for 15 mins then cycled it a few times with a wooden dowel.
Now have closer to 20 psi at idle ( my idle is a little too high) and between 30 and 40 on the highway (3000rpm).
Probably OK until winter storage, but will add oil pump check to the winter job list.

 

[Ken Ellis]

This is a little bit of a thread departure, so we can move it if needed.
If you have a head that has been skimmed a few times, it's my understanding that the compression can increase more than desired without doubling up on head gaskets. If paired with one of the low-compression blocks from SS, would that bring things back around to 'normal'? Perhaps not as cost-effective as a complete running engine from the used market, though.

 

[RootesRooter]

Series V oil pressure relief valves (PRV's) are set for 45 psi maximum when hot. 20 psi at highway speed rpm's indicates very worn bearings or a malfunctioning (sticking open) PRV. Read up on PRV's elsewhere here, as you could end up with the same problem on the next block. PRV's and differential ring wheel bolts are the two Achilles Heels of Alpines.

 

[Mike O'D]

Has the engine been taken apart to see what actually failed? Anyone else that has "thrown a rod" - what actually broke? Rod itself, rod bolts, other? Maybe hard to tell after the carnage?

Thanks.

Mike

 

[Barry]

Anyone else that has "thrown a rod" - what actually broke? Rod itself, rod bolts, other? Maybe hard to tell after the carnage?

Thanks.

Mike

"Throwing a rod" and poking a hole in the side of the block usually involves the rod breaking somewhere near the wristpin. The unrestrained small end of the rod then goes places it shouldn't. The rod can break for a variety of reasons (over-stressed, metalurgical or physical flaws, seized small end, seized big end, etc.). And yes, it can be difficult to tell where the problem actually started. I have seen rods break with absolutely no other damage and I have seen them turn the block, crank, cam and pistons into a scrap pile.

 

[Mike O'D]

Thanks Barry. I'm getting ready to do an engine rebuild and wondering if there is a good reason to go the "Chevy" rod route. If either end seizes up, it probably doesn't matter what rods are in there. I don't think there is anything wrong with the Alpine rods in general - correct?

 

[65beam]

For many the question is availability of parts. Internal parts such as rods,pistons, bearings, etc. are available from Sunbeam suppliers. Machine shops can R&R using parts made for the engine a lot quicker and easier than having to use and machine parts for various makes of engines in order to build an engine. If the engine built using standard parts has a problem down the road the time and expense to repair would be a lot less. I guess it's a matter of how much you want to spend, the length of time to build the engine and what do you intend to do with it. Just make sure you have a good oil pump.