4.1 block

[jdpolzin]

The turbo crank and bare block should be worth that and likely more. And let's not forget about the 4-barrel intake, heads, rods, and pan. Surely these items would fetch some $$$ also

Stick to your price, thats a very good price. The crank alone is worth $200-$250 if it's STD/STD and polishable. The 291 blocks, if in good shape with nice cylinder walls is worth $350 -$450 depending on how nice it is. If it has deep ridges on the cylinder walls from lots of mileage then of course it's worth considerably less.

 

[jdpolzin]

You're 6 hrs closer, you should go buy it-NOW!

Jesse, you know I have plenty of motors!

 

[usetaboost]

I bet your motor to boob ratio is way off at your house

 

[jdpolzin]

I bet your motor to boob ratio is way off at your house

Well I hope my wife only has two boobs! That would be a little odd! Maybe it would be fun???!!!!

 

[usetaboost]

I don't think there would be anything wrong with 3 boobs. Even if they're lopsided and uneven, still be fun at a party lol!

 

[mikemcvaney]

Is a 484 casting goog enough for a draw through with a big turbo?

 

[jdpolzin]

Is a 484 casting goog enough for a draw through with a big turbo?

The 484 block is fine. It's just a little more prone to cracking in the deck than the 291 casting. We are currently building one 484 to run high nine's and I have been running a 484 block with a mid 10 set up. No problems so far. ----Jeremy

 

[mikemcvaney]

Who makes forged pistons the ones I found are for a chevy rod dont want a stroker juast stock forged pistons

 

[charlief1]

Check with Mike a fullthrottle but I don't think anyone is making an off the shelf forged piston for the 4.1 right now.

 

[turbonut85]

Been down this road...Jesse...you are a CHEAP BASTARD.....Polzin's boob to motor ratio is WAAAAAYYY off....Ken...decent price, however the internal condition is unknown so I would be hesitant at that price for an unopened 484....There are NO off the shelf forged pistons for a 4.1 PERIOD. Hypers, used, or $900+ customs, or SBC with a custom made set of rods...that's what you're lookin at.

 

[Nick Micale]

The 484 block is fine. It's just a little more prone to cracking in the deck than the 291 casting. We are currently building one 484 to run high nine's and I have been running a 484 block with a mid 10 set up. No problems so far. ----Jeremy

This is somewhat off-topic, but Jeremy could you please let me know what your experience and problems have been with the 4.1 blocks cracking in the deck.

I do know the later 4.1 blocks are more desirable, but I thought that was because of the larger diameter oil galley, not a structural issue?

I have built a few 10 sec. 4.1's and not had any problems even though there is sometime a small crack or 2 from the head bolt hole which has had no affect on block integrity?

Thanks for your "educational" help.

 

[boostmaster]

Also off topic but I have a complete set of 0.30 (that's 3.995) forged pistons with stock rods made by Venolia Pistons for 350.00 shipped to 49 lower states if anyone is interested. PM me if any takers.

 

[charlief1]

If you'd offered them a while ago I'd have jumped on them.

 

[turbonut85]

Also off topic but I have a complete set of 0.30 (that's 3.995) forged pistons with stock rods made by Venolia Pistons for 350.00 shipped to 49 lower states if anyone is interested. PM me if any takers.

So, the piston size is 3.995 (using a mic and yielding a 3.995 measurement) for a 4.000" (=/- .001") finished bore size?? Or do they mic to 3.990 (+/- .001") for a 3.995" finish bore size?? Trying to clarify, and decide my level of interest...

 

[boostmaster]

So, the piston size is 3.995 (using a mic and yielding a 3.995 measurement) for a 4.000" (=/- .001") finished bore size?? Or do they mic to 3.990 (+/- .001") for a 3.995" finish bore size?? Trying to clarify, and decide my level of interest...

Pistons where built to a bore of 0.30 over that means a bore spec of 3.995. Standard bore is 3.965 + 0.30= 3.995. Hope that clears things up.

 

[jdpolzin]

This is somewhat off-topic, but Jeremy could you please let me know what your experience and problems have been with the 4.1 blocks cracking in the deck.

I do know the later 4.1 blocks are more desirable, but I thought that was because of the larger diameter oil galley, not a structural issue?

I have built a few 10 sec. 4.1's and not had any problems even though there is sometime a small crack or 2 from the head bolt hole which has had no affect on block integrity?

Thanks for your "educational" help.

Nick, you are certainly much more advanced in engine building than myself but in my experience comparing the 484 and the 291 casting blocks, I've noticed the 291 block has a lot more structure in the deck area. Although, they do crack between the head bolt hole and the water jacket on either casting number. I dont see this as being a structural problem in the cylinders but possible a leak between the headgasket and disturbing the integrity of the seal in the threads, possibly causing an oil/coolant mix. The only fix I try to do to keep uncracked blocks from cracking in the future is to remove the first couple of threads from the headbolt holes. I tried to find a few pics online of the 484 and 291 casting deck surfaces and came across another thread over on turbobuicks.com and is basically talking about the same problem. Here is a link:

4.1 casting numbers - TurboBuicks.com

Here are a couple pics from that thread, the first one is of the 291 block and the second is from the 484 block.

I do have to say that I see absolutely no problems using a 484 block. I run one now in my 4.1 car. It seems that people tend to read on here and as soon as they see one minor thing, they tend to think that it's junk! I just personally would say that the 291 block is superior to the 484 cast. I've talked with quite a few guys that have run the 484 and 291 blocks girdled and/or capped into the low 9's. The only failures I've heard of is the block splits by the front cam bearing journal. I've seen this twice so far and both motors were bottom 9's, one was a 484 and the other was a 291. It seems to me that the valley of either 4.1 casting is just too weak at that level compared to the 109's.

Just my 2 pennies! -----jeremy

 

[usetaboost]

production olds blocks have the same rough casting in the lifter valley and crack in similar places. One trick which should be done on all non 109 blocks is to debur the drain holes.

 

[jdpolzin]

production olds blocks have the same rough casting in the lifter valley and crack in similar places. One trick which should be done on all non 109 blocks is to debur the drain holes.

Thats is another good trick!!!

 

[usetaboost]

Yup. Doesn't hurt to leave the Buick flock once in a while to find info

 

[usetaboost]

I'm also working on researching other small tricks, but that's a whole other drunk conversation I'll have to save for another time.