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toyota crankshaft

Started by old white 73, May 08, 2015, 08:17:09 PM

old white 73

does anyone know if a toyota 2y crank been crammed into an avenger block, we lined the cranks up & they're almost identical in bearing spacing & the jap crank almost drops straight in. the nose & tail are a bit different- ie 6 flywheel bolts compared to 5 & modify nose to fit avenger timing gear,  though engine builder reckons he can work round those issues
toyota crank has a 77 mm stroke

oldschool

#1
Have heard of Toyota pistons being used, not the crankshafts! Even if you get the bearings and timing gear sorted, with a 77mm stroke the pistons will be popping out of the block! Standard 1500 stroke is 64.3mm while the 1600 stroke is 66.7mm and with the 1700 stroker kit on eBay it's 71mm. The 1500 and 1600 blocks are the same so a 1500 one can be bored out 1.21mm to use 1600 pistons as Richard did.

http://www.ebay.co.uk/itm/Avenger-Tiger-Talbot-Sunbeam-Ti-Crankshaft-Piston-Bearing-1700cc-Stroker-Kit-/271809182018?pt=LH_DefaultDomain_3&hash=item3f4916f942


Scarlet


NZTiger

I have used 2T Toyota pistons at 90mm which gives 1696cc and also 88.5mm giving 1640cc. To use these the little end bearing in rod needs to be reduced in size and a lot...about 5mm needs machining off the block.
Re longer stroke cranks, I looked at Nissan L16/L18 cranks a few years ago and they looked very promising, but the big problem with Avenger blocks when considering a longer stroke is that the block is not tall enough (Brazilian blocks are about 10mm taller for this reason). Using short rods is possible but this will reduce the rod ratio (which is already low) and that is not desirable for optimum efficiency.
I now use 89mm Nissan Pistons, these have a high pin position that allows longer rods which come from a Toyota 3sgte, the gudgin bearing needs sizing down. The Avenger crank is very strong and as the Toyota big end bearing is smaller than the Avenger, the crank is ground down to suit and also offset to make a stroke of about 68mm so the capacity is 1697cc.
The biggest problem I am having is getting a block with thick enough walls to take the overbore and so I have 1 sleeved bore on my current engine and I might need more.....

JoKer


old white 73

the hunt continues for a crank to butcher,- they're hard to find, most toy motors seem to have been exported by the scrappies or still smoking their way down the road.
did price that ebay stroker kit- @ $1900nz including freight & fees/tax etc to my door, tempting but we are keen to give the 2y a go for the hell of it

old white 73

FINALLY scored a crank, not the 1 i was chasing- engine builder figured if we're going this far may as go all out so its a 3y, @ 86 mm stroke. Dropping the crank off on monday- the fun begins!


old white 73

Heres a pic of the 2 cranks, avenger on top



old white 73

Dammit, cranks in- just a bit too tight- block will need chunks ground out the sides for clearance for the rods
At this stage capacity works out @ 2.1L. biggest hassle may be the need to make a custom flywheel, wasn't unexpected though.

old white 73

Might FINALLY be close to getting a suitable crank- hopefully motors supposed to turn up next week then it's all go engineering the improbable  :o

old white 73

Promises promises, >:( still without the right crank, all the other bits are now at rebuilder including my no. 2 block which has thicker walls than the 1 we were gunna use.
The 3y crank will still help with how much to narrow the centre main bearing & work out thrust bearing placement etc- if the y crank didn't have a bevel at the back the standard avenger thrust location WOULD have worked.

JoKer


old white 73

Seems all i'm doing too, following leads & dead ends, got offered a 1y- 1600cc hardly worth the effort as it's only @ 4mm increase over a 1600 avenger crank

oldschool

That's 1677cc...similar to the eBay '1700' stroker kits that were actually only 1683cc!!
If enough meat..the Toyota big ends could be offset ground 40 thou (1mm) to get 1697cc.

old white 73

GOT A CRANK!!!!!!!!!!!- not the 1 i was chasing, this is a 3T- still fits just the same, actually its better in that there's more metal for thrust bearings in standard avenger location, y series has a big chamfer there which entailed sussing out an alternative location for them.