1725 oil pressure relief valve

[jumpinjan]

...to replace the complete engine, (Which is what it requires), would set you back about the same as a V6 conversion would.

Come-on Joe. These 30 year old V6 motors are just as tired and monkey'ed up too and all the other pick-a-part parts one needs to scrounge up? I'll take a Alpine motor rebuild any day (and I'll be back on the road that same year )
Jan

 

[SIVAllan]

4) Breakout of the lifter bore area. I have no idea how it got that way, the lifter doesnt dwell that high in its bore, so even though its broken there, I dont think it will effect the lifter function. I would take a dremel tool and carefully remove sharp edges inside the bore and not worry out it.

HTH

The picture was not clear as to engine block orientation. The block was upside down on a stand when the lifter bore picture was taken. The damaged area is at the bottom. Here is another picture; does that change the analysis?

Allan

 

[RootesRacer]

Yeah, that makes me feel not so good (the lifters do dwell in that section).

You could sleeve it, then I'd stand behind the rest I said.


I'd say whatever did that probably didnt happen recently, perhaps a thrown rod where pieces of the motor were whipping a round and one made its way up there where the cam hit it?

Is there any evidence of pieces of metal striking the sides of the block?

 

[SIVAllan]

No, I don't see any dents. There is a small chip out of the block just at the edge of the bottom of the cylinder nearest the damage zone. It doesn't extend into the cylinder wall but is is quite close.

I managed to remove the cam and lifters from the parts car block. If sleeving needs to be done, it may be a better candidate. The lifter bores look good. The cam has one small scuff on it's central "bearing lobe," so it goes on a shelf.

In general, can you offer any info on sleeving piston bores?

Who does that, a machine shop? Is it super expensive? Is it as reliable as an unsleeved block?

Before going too far in a search for a block, it would be very helpful to have a general sleeving assessment and cost guestimate.

Then again, I have a pair of the small painted headlight bezels that I understand are SO RARE that they are worth in trade a WHOLE NEW CAR or at least a new RACE ENGINE ...

Thanks again.

Allan

 

[jumpinjan]

Sleeving is not a big problem. There is a major expense in doing the machining the first time sleeves are installed, but the next sleeve replacement (after those wear out) will not be as expensive. The sleeves are better material too. L.A.Sleeve is a huge manufacturer of them.
Jan

 

[SIVAllan]

Jan - thanks.

I have a couple feelers out on replacement blocks, will see how that goes.

Also will take Air-Pine's banged up block, along with the part's car block, to a local machine shop for a review.

I don't know the first thing about blocks at this level of detail. One block is early, and banged up. The other is very late, and has its pistons frozen to the cylinders. From what little I can tell, the later block/engine died from a cooked head.

Sleeving makes sense, from a long term perspective. The expense is a little scary. When I turn up a $number, I'll let folks know, in case others are interested in sleeving.

Jose - I hear you on the V6. Installing a V6 is an option I intend to pursue, but not on the Air-Pine. May be irrational but I've my mind set on it running Sunbeam under the bonnet. Something about the quirky Sunbeam engines got ahold of me.

Allan

 

[Jim E]

I would forget sleeving, seem familiar, it is about $100 a hole to have done. They bore the block heat it then jab a sleeve in the hole, think of a piece of pipe. The block cools off and the sleeve is stuck, repeat three times. Then bore the block again to fit the pistons. You run one long enough to need sleeved again you repeat the above, bore out the old sleeve and stick in a new one.

So why not just bore the block 80 or 90 over or near that and order a set of custom pistons from J and E or Ross or venolia. Just make sure the rings are available for the bore you settle on. The key is bore first then order that way if you hit a void you can still spend a fortune and sleeve it if you got to have a numbers matching engine.

Were I running one of these lumps and especially if I were racing one I would do this and add the Chevy rods, run a chevy wrist pin. Then you can use most any block out there.

Think Steve S. sent venolia a piston and they made a set for stock rods right Steve? What was it about $100 over the cost of the VB pistons? Is there a cost break for ordering 8?

 

[sunbeam74]

Jim,

The total was 585.00 with rings, pins, pistons, and shipping. It takes about 3 weeks. Best think to do is to simply tell them your bores are "X" dimension (cleaned up) and you will need pistons to fit that bore. (For example 2.2580" or whatever)

They will size them correctly.

As for the wrist pins... yes you can get them so they fit the Alpine rod but I had to order one of Venolia standard size pins. It was slightly larger if I remember correctly than a stock Alpine pin. So, the shop simply honed the rod little ends to the correct tolerance.

Unfortunatley, they wouldn't talk discounts until 50+ were ordered. Ouch.

Steve

 

[SIVAllan]

Took the parts car block to a machine shop for a chat.

The machine shop guys are a lot of fun to visit. They are the ultimate "gearheads."

They spotted a crack in the block even through the grease before I sat it down, a crack
due to water freeze that would require a weld, then ran a scope of some sort on it which verified their initial observation. So that block goes on a back shelf for some future generation to repair with future technology.

Asked them about sleeving. Their off-the-cuff guestimate was about 200$ to sleeve plus about 300$ for labor. They didn't care what sleeve size or what size piston, just said to let them know.

Asked them about sleeving a lifter bore, but they said that requires a machine that they do not have, and they had no recommendations.

Jan mentioned L.A.Sleeve and their web site is stupendous. I tried to call a couple times, did not get through, and it's not clear if they sell sleeves outright, or if they want the block shipped to them.

Allan

 

[Bill Blue]

Allan, something to consider in favor of custom pistons. You will be getting a modern, lightweight piston that is superior to the OE item.

If you run out of local engine options, contact me. I have a "runner" and that's about all I know about it.

Bill

 

[SIVAllan]

Bill, thanks.

I'm sifting options and hope to find the path to a self propelled car soon. The Air-Pine has sent me to school but the subjects are interesting. A running engine certainly has advantages

I am not surprised that the old pistons can be bettered. I'm just beginning to look into pistons.

I looked at an ad today that featured a 4 ring piston. Is that of any advantage over 3 ring pistons?

Allan

 

[Bill Blue]

Bill, thanks.

I looked at an ad today that featured a 4 ring piston. Is that of any advantage over 3 ring pistons?

Allan

Beats me. I think of 4 ring pistons as old technology. They were oil, scraper and two compression. Now the industry seems to need only the oil and compression rings. If given the choice, I think I'd go with the 3 ring design. I see that as probably part of the "better" technology. Sometimes, less is better than more.

If your interested, I can make you a deal on the engine you could hardly turn down.

Bill

 

[Wombat]

The Series I had 4 ring pistons, 3 near the top and one at the bottom of the piston. Later ones were only 3. I guess they got the oil rings working better ....

 

[husky drvr]

Four ring pistons are both heavier and more fragile than three ring pistons. The use of four ring pistons is not the best idea if you have any intentions of using a heavy foot on the loud pedal. Yes, they are adequate but not the best idea in a sports car.

The fourth ring is in a groove below the wrist pin which means the lower skirt must be thicker to support the ring. Also, due to the ring groove and the needed ports to pass the oil it scrapes off the cylinder wall, a new stress riser is introduced into the thrust face of the piston making it prone to failure at a totally new location. If I am not mistaken, Rootes did not install the fourth ring in new engines that had those pistons. The fourth ring location really only provided a way for someone who had a worn engine to rering and use a second oil ring in the forth location which would be in a section of the bore that should not be as worn as the upper part of the cylinder.

Just my thoughts,