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24v swap missing info

Posted: Fri Mar 13, 2020 10:12 am
by sh0rtlife
ok so ive been trolling around trying to find pics and information and have only found tidbits and no "solid" info no matter how i search, ive no doubt the info is here and at alfabb but i sure cant find it after a couple weeks of trolling and trying i give up its time to just ask

so looking to drop a monster 24v into a milano chassis, first off this is NOT a stock 24v(details of its guts later) and it has already been in a 105/115 chassis

so lets start at the bottom up, whats the deal with the oilpan, obviously i need to change it over to the gtv6/milano pan, what exactly needs to be done to make this happen?, i assumed that the 105/115 pan had to be modded to fit but see no signs, does the 24v just have the 4cyl pan mounts but not the 12v v6 mounts on it?....yeah i havnt pulled the pan yet from one of my 12v stash

also what needs to happen on the oiling, i assume the pickup and pan go together as loosely matched pair, can i retain the pump in the engine and just swap the pickup?

now lets move out back, so since it had a clutch hanging off of it ill need to swap to the transaxle flywheel, now i assume i use a v6 bell and flywheel , but need to re-balance, where i get confused is some of the balance as well as the "spacer" or late flywheel

balance...this engines got very little mileage on it and it would be a SHAME to open it up more than i need to, so can i safely get a flywheel "match" balanced to the existing flywheel or do i need to do a full tear down and full balance?, i figure if its the latter theres very little reason i couldnt re-use every bearing as is as the engines life right now could be better measured in hours not miles, obviously id have to meticulously mark everything and acquire torque specs

engine mounts, standard v6 affair or do i need something special?, mind you the axle shaft/oil filter adapt has already been converted to just be a filter

"heat" what are my best options for heater hose ports?, ideally since this is a HEAVILY modified chassis id like to come out the rear of the block, can i just come off one head or both heads?...looking for good flow, up front the water pump and t-stat stuffs already swapped, but i have a 3.0 12v 164 engine on the shelf with very nice t-stat housing up front with no extra porting for a "clean" look that id like to use just need alternate heater hose locations to use it

exhaust, mentioned the chassis is HEAVILY modified and i have a plan for the exhaust thats..well...a wee bit 1950s going up and over to the corner of the cowling and down behind the front wheels then under the chassis, this will all fit under the hood so forget what your thinking, this is for ground clearance and room to make something more ideal, ive seen alot of discussions about tube length but nothing definitive, and more often than not it all gets restricted to what you can fit, obviously in my case ive got the room to run, so whats the ideal tube length with/without collector...remember this isnt a stock 3.0 its a monster in itself, also whats the ideal tube size?, the oval ports are screwin with my brain on that, what about dual exhaust size, whats good here whats overkill

breathing with ITBs
whats the ideal setup here, ive done too much research and my heads spinning, ive got room to run LONG trumpets or stacks, i believe with current clearance i could run something in the 14inch range(obviously ill be making them), but this brings up a very unique situation, are stacks best left as stacks or would it be better to have a plenum box that slipped over them, current "idea" would be to build a plenum box into the hood as well as fresh air coming from just in front of the rad feeding it thru a flat filter, the question here is this
whats the ideal runner length?
whats the ideal plenum size?
is it better to have the trumpets flush floor or stepped up into a plenum? and if so how much

Re: 24v swap missing info

Posted: Wed Apr 01, 2020 9:18 pm
by milanoguy
Well that's a lot of questions, but here's a few thoughts.

I don't think a plenum can ever be too big. I'd look inside a SPICA airbox for overall guidance.

Here's a link to a custom plenum made for a car engine that was modified for use in a homebuilt airplane.

Here's an SAE article on intake plenum size.

"..Plenum sizes were varied from 2 to 10 times engine displacement (1.2 to 6.0 L) and engine speeds were varied from 3,000 to 12,500 RPM. Performance metrics including volumetric efficiency, torque and power were recorded at steady state conditions. Experimental results showed that engine performance increased modestly as plenum volume was increased from 2 to 8 times engine displacement. Increasing plenum volume beyond 8 times engine displacement resulted in significant improvement in performance parameters.

The Effects of Intake Plenum Volume on the Performance of a Small Normally Aspirated Restricted Engine
L. J. Hamilton and J. E. Lee
SAE International Journal of Engines
Vol. 1, No. 1 (2009), pp. 1312-1318

Hope this helps

Re: 24v swap missing info

Posted: Mon Apr 20, 2020 5:14 pm
by Duk
With regards to inlet manifold design, I'd suggest that you look at very capable normally aspirated engines.
Notably the Ferrari 458 and the 991 chassis Porsche 911 GT3.
Both make about 125hp/litre and the Ferrari engine achieves a BMEP number of 15+.
Importantly, neither of them use ITBs.
If you could build anything you wanted, I'd suggest a similar approach to what Ferrari used, with 2 plenum chamber, 2 throttle bodies and valves that join or separate the plenums.