F1technical.net

I have long pondered an engine design dreamt up out of bits of scrapyard junk.
The old blueprint images released by Honda of their late 80's V6, V10 and V12 all share a similar design dna, namely the 75 degree bank angle.
Isuzu built a 75 degree V6, built under licence from Hondas design bench, the cylinder heads water passages have a nice entry manifold similar to a motorcycles, nice shallow valve angle, nice high port roof, cross bolted main caps.
If you were to obtain 2 early blocks with the short deck, cut a split line in middle of rear 2 cylinders of one block and the front 2 cylinders of the other you have the basis of the V10 block.
Naturally that pair of bores need sleeving after the tig welding unifies both blocks, a turned aluminium bar bolted in the crank tunnel with the caps should keep everything lined up.
The bar should be aluminium as the block needs pre heating before tig welding, steel has a different expansion and would leave 'walk' marks.
I found this out trying to weld a motorcycle crankcase which was holed.
Ok, so block done.
Now the crank, a Volvo crank, shortest stroke obtainable, cut the crank dead centre of main journal on all 5 main journals, this could be done with an edm wire cutter to keep as much parent metal, these 6 segments are set up on a rotary table and the half main journal milled to an ideal stroke and diameter for the new hollow bush to be pressed on.
The hollow bush should be a hardened and ground bush with press fit interference on Volvo crank segments new diameter.
Hardened and ground bushes are easily obtained from bearing manufacturers (skf) as inner races for needle roller bearings.
Now to find some motorcycle conrods to suit this bush outer diameter?
Some motorcycle pistons, Crf450? Drz400?
The camshafts are going to be billet, no easy solutions here.
Bmw throttle bodies, M5?
If i had the keys to a well equipped machine shop. [-o< [-o< [-o< [-o< [-o<

Sounds cool. Have you seen the work of Alan Millyard?

Check him on youtube...he siamesed a few engines in his time

The crank was the big hurdle until i saw Allen make a pressed up crank on Youtube.
He presses up camshafts too, but those were high revving profiles, Isuzu truck camshafts would only be tiny lobes, like an old volkswagon beetle, a golden oportunity for a billet cam.

coaster wrote: ↑

28 Nov 2022, 12:38

I have long pondered an engine design dreamt up out of bits of scrapyard junk.
The old blueprint images released by Honda of their late 80's V6, V10 and V12 all share a similar design dna, namely the 75 degree bank angle.
Isuzu built a 75 degree V6, built under licence from Hondas design bench, the cylinder heads water passages have a nice entry manifold similar to a motorcycles, nice shallow valve angle, nice high port roof, cross bolted main caps.
If you were to obtain 2 early blocks with the short deck, cut a split line in middle of rear 2 cylinders of one block and the front 2 cylinders of the other you have the basis of the V10 block.
Naturally that pair of bores need sleeving after the tig welding unifies both blocks, a turned aluminium bar bolted in the crank tunnel with the caps should keep everything lined up.
The bar should be aluminium as the block needs pre heating before tig welding, steel has a different expansion and would leave 'walk' marks.
I found this out trying to weld a motorcycle crankcase which was holed.
Ok, so block done.
Now the crank, a Volvo crank, shortest stroke obtainable, cut the crank dead centre of main journal on all 5 main journals, this could be done with an edm wire cutter to keep as much parent metal, these 6 segments are set up on a rotary table and the half main journal milled to an ideal stroke and diameter for the new hollow bush to be pressed on.
The hollow bush should be a hardened and ground bush with press fit interference on Volvo crank segments new diameter.
Hardened and ground bushes are easily obtained from bearing manufacturers (skf) as inner races for needle roller bearings.
Now to find some motorcycle conrods to suit this bush outer diameter?
Some motorcycle pistons, Crf450? Drz400?
The camshafts are going to be billet, no easy solutions here.
Bmw throttle bodies, M5?
If i had the keys to a well equipped machine shop.

I like the way you think

coaster wrote: ↑

28 Nov 2022, 20:47

The crank was the big hurdle until i saw Allen make a pressed up crank on Youtube .....

he was known for eg turning two 3cylinder 2 stroke Kawasakis engines into one 4 or 5 cylinder engine

but yes early 4 stroke Honda Kawasaki Suzuki & Yamahas cranks were designed as per 2 stroke roller bearing cranks
so could be reset at any angle (some had splines - in effect controlling the angle permutations available)
Suzuki was seemingly the last to do these
and there must be some 2 strokes ie some outboards and aviation - also offering parts for home-made crank angles

there's serious precision thick metal and very large forces involved in this type of crank design

if the cylinder liners and crankpin grind were shuffled a bit a 75 deg block could match the ideal 72 deg of a 10 or 5 cyl

Why not just buy a M5 V10?

72 degree (75) motors have a sweeter idle, 90 degree V10's have a lopy idle, sound quality.

Does the 72/75 degree offer advantages over the 90 degree ? Why don't more racing series allow a 72/75 degree V?

In MotoGP, Honda and Aprilia were using 72/75 degree V4's but switched to a 90 degree V4 like the ever conquering Ducati.

If I remember, in F1 back in 2005, the BMW and Toyota were the most powerful V10's. Both were 90 degrees.

Me personally, if it's a V-Twin, V4, V6, V8, V10 then I would stick to a 90 degree. If it's a V12 I would use a 60 degree.

75 degree had been used by ilmor and ferrari for shared crankpin V10's, its a proven quantity.
I cant comment for the world of other possibilities since the topic focussed only on the honda/isuzu v6.
V4 75 degree usually gets a balance shaft.
I drew a V10 based on the ford taurus V6, but being a 60 degree motor it was a risky path.
Renault figured out 67 degrees with a shared crankpin and no balance shaft, maybe it had a trick like uneven crankpin phasing in the TJ V10 discussed in this forum.
75 seems a safe path.

coaster wrote: ↑

29 Nov 2022, 08:11

75 degree had been used by ilmor and ferrari for shared crankpin V10's, its a proven quantity.
I cant comment for the world of other possibilities since the topic focussed only on the honda/isuzu v6.
V4 75 degree usually gets a balance shaft.
I drew a V10 based on the ford taurus V6, but being a 60 degree motor it was a risky path.
Renault figured out 67 degrees with a shared crankpin and no balance shaft, maybe it had a trick like uneven crankpin phasing in the TJ V10 discussed in this forum.
75 seems a safe path.

On this forum on another thread someone posted how they modified a 90 degree V6. He said it's not real smooth down low in the rev range but it likes high rpm where it shines.

For racing, I think a 90 degree V6 is the way to go. Look at F1, Indycar and Le Mans prototypes which use 90 degree V6's.

Yes, i would refer the 90 degree V10 to BrianG's thread 'f1 crankshaft, a closer look', the main concern is the uneven crankpin phasing, that TJ V10 firing order would be like a pile of pots and pans rolling down a staircase.
Even fire, shared crankpin seems the safest path, give or take 1.5 degrees, close enough.

Trying not to derail the thread, but would a 1.6l I6 be longer or shorter than the 2.4l V8?

Would the I6 have the rigidity to be a weight bearing structure without add a lot of excess material for support?

An inline 6 will be longer than a V8.

graham.reeds wrote: ↑

29 Nov 2022, 12:09

Trying not to derail the thread, but would a 1.6l I6 be longer or shorter than the 2.4l V8?

Would the I6 have the rigidity to be a weight bearing structure without add a lot of excess material for support?

I think that all inline engines need a space frame. Adrian Newey mentioned that when F1 thought about inline's a few years ago.

coaster wrote: ↑

28 Nov 2022, 12:38

I have long pondered an engine design dreamt up out of bits of scrapyard junk.
The old blueprint images released by Honda of their late 80's V6, V10 and V12 all share a similar design dna, namely the 75 degree bank angle.
Isuzu built a 75 degree V6, built under licence from Hondas design bench, the cylinder heads water passages have a nice entry manifold similar to a motorcycles, nice shallow valve angle, nice high port roof, cross bolted main caps.
If you were to obtain 2 early blocks with the short deck, cut a split line in middle of rear 2 cylinders of one block and the front 2 cylinders of the other you have the basis of the V10 block.
Naturally that pair of bores need sleeving after the tig welding unifies both blocks, a turned aluminium bar bolted in the crank tunnel with the caps should keep everything lined up.
The bar should be aluminium as the block needs pre heating before tig welding, steel has a different expansion and would leave 'walk' marks.
I found this out trying to weld a motorcycle crankcase which was holed.
Ok, so block done.
Now the crank, a Volvo crank, shortest stroke obtainable, cut the crank dead centre of main journal on all 5 main journals, this could be done with an edm wire cutter to keep as much parent metal, these 6 segments are set up on a rotary table and the half main journal milled to an ideal stroke and diameter for the new hollow bush to be pressed on.
The hollow bush should be a hardened and ground bush with press fit interference on Volvo crank segments new diameter.
Hardened and ground bushes are easily obtained from bearing manufacturers (skf) as inner races for needle roller bearings.
Now to find some motorcycle conrods to suit this bush outer diameter?
Some motorcycle pistons, Crf450? Drz400?
The camshafts are going to be billet, no easy solutions here.
Bmw throttle bodies, M5?
If i had the keys to a well equipped machine shop.

What's the end goal? What are you planning to put this into?