Home made V12 .... my uncle's next project

[radtechtips]

most likely. given the likely cost for this it would make sense as well as to have as much strength and balance for a engine as huge and powerful as this. what is the total engine size

6 liter IIRC

 

[Sidekicknichola]

First time I've seen a block made from a custom weldment. My initial impression is that they better be damn good welds.

Lets hope they are!

How long has your Uncle been working on it?
What type of ECU does he plan on using?
Are those 1JZ heads or has he done something custom to them?
How much power is he looking to get out of this?

Could of months now, but this is sort of his "back burner" project... he has a few other things cooking he would like to finish first. They were the 2jz-gte engines that have obviously been tweak to fit at 120* to each other.
... as far as power, thats a great question, I think the plan is get it running, then worry about what it can handle.

I'm traveling for work for the next 2 weeks so probably won't be much for updates in that time.

 

[Ferzerp]

What is the final weight of the whole engine going to be?

 

[norseamd]

how is the block made? crankshaft placement goes where

 

[Squeetard]

6 liter IIRC

Going to be bigger than that. The stroke has to be longer than stock.

how is the block made? crankshaft placement goes where

You can see how the block was done. It was not cast. Instead he fashioned it out of plates and then tig welded in some main bearings he cut out of something else.
Not sure what you mean in the second question.

 

[crashtech]

I don't think the main webbing was cut from something else, unless it was a from a billet block, which is a vanishing improbability.

 

[exdeath]

Crank goes wherever you want at this stage. Machine shop will center it perfectly when they line bore it.

That's not something you orient or set yourself. You have no hope in fabricating and lining up something like that perfectly by hand. You line bore a rough undersized assembly and that's when its set in stone forever.

Its like, do you try and weld and match up holes yourself to .0001 or do you implement solid blocks and drill them all at once together on a machine shop jig? The former will not work. The latter is how machining works with any kind if precision assembly. You aren't micing individual journals and welding them into a final assembly, it would never come out right in a million years.

By hand you can make sure the journal bulkheads are square, spaced correctly, cylinder bores square and correct angle, etc,then line bore. Your deck to crank centerline will be made perfect by where the line bore is centered, you don't try to build it that way lol.

 

[Squeetard]

I don't think the main webbing was cut from something else, unless it was a from a billet block, which is a vanishing improbability.

I think they were. Let's ask Uncle!

 

[norseamd]

Not sure what you mean in the second question.

in the two rusted block you can see plug holes. since this is a fabricated engine i am not sure what is what. is that where the old crankshafts used to go. one crankshaft is doing the job of two old crankshafts. my guess is that the crankshaft is lower compared to the cylinder then it used to be and that you would need longer piston rods

 

[exdeath]

how is the block made? crankshaft placement goes where

Side angle side where side is crank center to deck distance and equal on both sides and angle is V angle, 60 or 120 degs for firing order purposes. The point where the two intersect is thus fixed and that is what will be measured and set up by heavy duty precision machinery during a line bore operation.

Block will be decked and cylinders will also be bored to be true to the crank center as well regardless how close it might be or how perfect the cylinders and crank case ended up being.

Its all final machine work, that stuff is impossible to do individually with hand tools.

In other words he welded in solid rectangular slabs and caps and had the whole thing bored as one. You just have to be crude ballpark on the rough block, the final machining takes care of the rest and ensures everything is perfect.

You can start with a giant lump of rock if you want. As long as you line bore, deck, and torque plate cylinder bore, you can have a working engine block. Those are the three most important relationships. Even cylinder bore centerline to rod journal can be slightly offset within reason , that's why all engines have loose crank endplay and rely on crank thrust bearings to allow for that tolerance and to precisely locate the crank during final assembly.

Any errors resulting from making a custom block by hand will be ironed out at the machine shop same as it is with every imperfect sand casted factory block.

 

[deerslayer]

More pics!

 

[crashtech]

^ What exdeath said, it all starts with establishing a precise crank centerline and works outward from there. the deck surfaces will be milled on a parallel plane from said centerline at the desired distance from it, and with the desired V angle measured on the perpendicular. Cylinders can then be bored concentric to an imaginary line perpendicular to the deck and intersecting the centerline with the correct fore-aft bore spacing, etc., etc.

 

[norseamd]

understand how this works on a regular engine. but i am wondering how he adjusts the crankshaft from where the 2 crankshafts were before to where the 1 crankshaft is now.

v12 are 60 or 120. v8 is 90

already knew that but thankyou

 

[exdeath]

V12 crank is identical to an I6 crank but with two rods per journal. Its an entirely new single crank, there were never two cranks "merged".

The two cylinder banks are installed to the crank case offset from each other by the thickness of a single rod cap. That's it.

 

[norseamd]

thought the cylinders were part of the block. is he using all new cylinders. yes i know there is only one crankshaft. but he is replacing 2 crankshafts with one. the question is where is the crankshaft in relation to one bank of cylinders than it was before. is it farther away

 

[softshadow]

Lets hope they are!

Could of months now, but this is sort of his "back burner" project... he has a few other things cooking he would like to finish first. They were the 2jz-gte engines that have obviously been tweak to fit at 120* to each other.
... as far as power, thats a great question, I think the plan is get it running, then worry about what it can handle.

I'm traveling for work for the next 2 weeks so probably won't be much for updates in that time.

Thanks.

 

[deadken]

... how is the crankshaft going to be placed compared to the originals

You can just eyeball those things... It'll self-clearance upon start up. You just need to change the 'break-in oil' within the first 500 miles.

Hey OP, I have to admit, your crazy uncle is WAYYYY cooler than my crazy uncle!

 

[exdeath]

thought the cylinders were part of the block. is he using all new cylinders. yes i know there is only one crankshaft. but he is replacing 2 crankshafts with one. the question is where is the crankshaft in relation to one bank of cylinders than it was before. is it farther away

The deck height to crank centerline of both banks will be the same. Both banks are independent I6 engines 120 degrees out of phase with each other (All V12s are, not just this one). When the left bank is 0 TDC the right bank is -120 TDC.

Again, its a special case with the V12 where the crank is literally just a shared rod journal I6 crank. The two banks can be thought as independent I6 engines running at different crank angles.

 

[norseamd]

The deck height to crank centerline of both banks will be the same. Both banks are independent I6 engines 120 degrees out of phase with each other (All V12s are, not just this one). When the left bank is 0 TDC the right bank is -120 TDC.

so what is the deck height to crank centerline of the combined engine compared to the regular old engine

 

[JCH13]

so what is the deck height to crank centerline of the combined engine compared to the regular old engine

Unless he wants to change compression or have 12 custom/different connecting rods then it will be the same as the original I6 engines.

 

[crashtech]

I would consider custom connecting rods to be a highly likely eventuality, they will likely need to be longer, and the bearing may need to be narrower, depending on how much room there is on the wider V12 rod journal.

 

[softshadow]

I hate to bump this but I was wondering if there has been any progress?
Thanks

 

[Sidekicknichola]

I'll be seeing my uncle this weekend... there is a big car show here in Minneapolis, "Back to the 50's" he always attends with my dad so I can pick his brain on where things are.

for fun, his old Buick that was won oodles of awards

His other project he just wrapped up too, a old school remake of a twin engine dragster

 

[norseamd]

did not know back to the 50s was this weekend

 

[softshadow]

I'll be seeing my uncle this weekend... there is a big car show here in Minneapolis, "Back to the 50's" he always attends with my dad so I can pick his brain on where things are.

for fun, his old Buick that was won oodles of awards

His other project he just wrapped up too, a old school remake of a twin engine dragster

Great. Thanks for responding and posting pictures on his other projects.