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Robbie
Robbie SuperDork
6/23/16 10:23 a.m.

If stock EFI BBF pistons bump the compression, I too would lean that way. and I bet you can get them for nearly free as well (buy whole motor, take pistons and maybe rods, scrap/sell the rest).

Also agree that if you keep the RPMs and lift down, the stock valve train should be fine.

What about opportunities to reduce weight of the rotating assembly? I know this might be starting to get wacky, but things like knife edging the counter weights and grinding a bit of the rods to match? Run lightweight oil? Dual timing chain swap to single, etc.

PS, strapping a Harley motor to the front and hanging it out the grill is the best idea I have heard in months. To further improve that idea, make the sole purpose of the Harley motor to turn a belt for a supercharger.

Appleseed
Appleseed MegaDork
6/23/16 10:42 a.m.

The bad thing about weight removal of rotating parts is the re-balence of said parts. Malory metal and machine shop time can get spendy.

¯\_(ツ)_/¯
¯\_(ツ)_/¯ Dork
6/23/16 10:43 a.m.

In reply to Robbie:

Two, TWO superchargers dammit!

Robbie
Robbie SuperDork
6/23/16 10:51 a.m.
¯\_(ツ)_/¯ wrote: In reply to Robbie: Two, TWO superchargers dammit!

Good idea. Just strap this baby to the vtwin crank.

tuna55
tuna55 MegaDork
6/23/16 10:58 a.m.

In reply to Robbie:

OK normally I think the idea of adding forced induction for Lemons is a pretty bad one, but a Harley motor used solely to turn a compressor for boost is fantastic. It would sound awful, the theme opportunities are practically boundless, and you could limit the boost to like 2 psi so the biggest issue would be the added weight, and come on, it's not a large percentage of the overall.

volvoclearinghouse
volvoclearinghouse SuperDork
6/23/16 11:14 a.m.

Harley motors are pretty useless. Using one to turn an air press is probably the best use one could come up with for one.

Bonus points if you use the exhaust of the Harley engine to spool a turbo. And connect the drive of the engine to nothing.

pilotbraden
pilotbraden SuperDork
6/23/16 11:30 a.m.

Use one cylinder on the Harley as the compressor, use the other cylinder to power the compressor side.

snailmont5oh
snailmont5oh Reader
6/23/16 11:30 a.m.

Use the Harley exhaust to spin a turbo, and the crankshaft to spin the twin supercharger setup. You'd need something on the crank to load the engine so that it could spool a turbo.

tuna55
tuna55 MegaDork
6/23/16 11:32 a.m.

So the Harley has a turbo which is plumbed back to the Harley, and a supercharger which is plumbed into the 460, and the alternator and water pump for the 460 is powered by the Harley.

volvoclearinghouse
volvoclearinghouse SuperDork
6/23/16 11:33 a.m.

What were we talking about again?

tuna55
tuna55 MegaDork
6/23/16 11:43 a.m.
volvoclearinghouse wrote: What were we talking about again?

The topic is "How to win Lemons with the LTD"

I think we're still on topic!

Ring packages. Does anyone have real information? Is it worth buying more modern pistons to get better rings? Worth gapless rings?

Thinkkker
Thinkkker UltraDork
6/23/16 11:59 a.m.

So Harley engine......

I like the idea of moving all the charging, water pump rear mounted radiator? and such to the harley engine. Plus, some sort of air charging system.

volvoclearinghouse
volvoclearinghouse SuperDork
6/23/16 12:07 p.m.
pilotbraden wrote: Use one cylinder on the Harley as the compressor, use the other cylinder to power the compressor side.

I really like this idea. Remove the pushrods from one cylinder and put a check valve arrangement in the spark plug hole so that side acts as a compressor. Get an air tank to store volume when the engine's idling (braking) for W.O.T. needs.

A V-twin Harley motor running on 1 cylinder has got to sound badass.

volvoclearinghouse
volvoclearinghouse SuperDork
6/23/16 12:08 p.m.
tuna55 wrote:
volvoclearinghouse wrote: What were we talking about again?

The topic is "How to win Lemons with the LTD"

I think we're still on topic!

Ring packages. Does anyone have real information? Is it worth buying more modern pistons to get better rings? Worth gapless rings?

Hadn't you mentioned moly rings or something, for instant break-in? That would be ideal, since we'll essentially be breaking this engine in while turning laps, most likely.

tuna55
tuna55 MegaDork
6/23/16 12:12 p.m.
volvoclearinghouse wrote:
tuna55 wrote:
volvoclearinghouse wrote: What were we talking about again?

The topic is "How to win Lemons with the LTD"

I think we're still on topic!

Ring packages. Does anyone have real information? Is it worth buying more modern pistons to get better rings? Worth gapless rings?

Hadn't you mentioned moly rings or something, for instant break-in? That would be ideal, since we'll essentially be breaking this engine in while turning laps, most likely.

Moly rings are a given, absolutely.

The question is to spend money or not on a piston which uses thinner more modern rings.

ross2004
ross2004 Reader
6/23/16 12:15 p.m.

Might as well put in a set of low-tension rings and a six stage dry sump at this point.

gearheadmb
gearheadmb HalfDork
6/23/16 12:49 p.m.
volvoclearinghouse wrote: What were we talking about again?

If you have a $500 spending limit, What is the best way to spend thousands so that the car never makes it out of the project phase and eventually gets turned in for scrap.

Gasoline
Gasoline SuperDork
6/23/16 1:00 p.m.
bluej
bluej UltraDork
6/23/16 1:28 p.m.

find a junky supercharged jetski motor and pipe the charge-air from it to the 460 instead?

RealMiniParker
RealMiniParker UberDork
6/23/16 1:50 p.m.
volvoclearinghouse wrote: A V-twin Harley motor running on 1 cylinder has got to sound like ass.

FTFY

Current Harleys have EITMS - Engine Idle Temperature Management System - that cuts fuel and spark to the rear cylinder, when certain criteria are met: idle engine speed, zero throttle input, 0mph, and extremely high head temp, all together. When those conditions are met, it shakes like a dog E36 M3ting razor blades (well, more than the usual Harley motor), as the front cylinder fires and the rear is essentially just an air pump.

volvoclearinghouse
volvoclearinghouse SuperDork
6/23/16 9:18 p.m.

In reply to RealMiniParker:

So, Harley took an already sub-optimal design, and made it worse? How are they still in business?

Getting back to Project BBF, forced induction is off the table for now. As gearheadmb pointed out, this is turning into a great way to ensure this project never gets finished. I get maybe 30 to 45 minutes 1 or 2 nights a week to tinker with this engine, and it needs to be ready in time to plunk it into the LTD before next year. We ran our race for 2016 already...

volvoclearinghouse
volvoclearinghouse SuperDork
6/24/16 9:09 a.m.
bluej wrote: For headers, is this a decent price for a kit? https://www.amazon.com/gp/aw/d/B007VRF83E/ref=aw_wl_ov_dp_2_2?colid=X0U8R5NRRGAX&coliid=I1K2IKPWS3Q4ZF

I'm not sure, but it doesn't include the flange that bolts to the engine. That seems like the hard part. They sell just those flanges, for about $125/ set. At $200, we're bumping up against "cheap header" territory, though. As Tuna pointed out, this car has no inner fenders, no power steering, and lots of space under the hood. So something off-the-shelf (maybe for a truck?) might work.

curtis73
curtis73 PowerDork
6/24/16 9:39 a.m.

My two cents:

460s are short stroke, big bore engines. Don't be afraid to work a little more on the porting and spin it to 6000 rpm. At 8.5:1 you can keep the spark timing conservative and keep 87 octane. BBF heads are not known for quench or swirl, so at 9:1, prepare for 91 octane unless you spend some serious time getting piston quench just right. Go with a piston crown that is as flat as possible. Not only does it help quench, it does wonders for flame front speeds. It will help detonation tolerance from two aspects: 1) quench, and 2) not slowing the flame front means that the proper ignition advance will be a couple degrees later.

Above all, match the flow, compression, and cam timing to match. If you can't get 300cfm from the intake port, you won't be making power above 5500 rpm.

I would spec a cam in the 220/230 degree range (at .050", not advertised) on a 110 LSA. Peak piston velocity is not a huge concern so you don't have the violent inlet pressure changes quite like (for instance) an Olds 455. Less cam, broader torque curve, and the short stroke means it can stretch that breathing room a bit higher than a long stroke.

My suggested recipe: flat tops, 9:1, .030" quench if you can, comp XE262 (sounds stock, roasts tires), plenty of porting on the exhaust side, mild porting intake side, RPM-style dual plane intake, 750 cfm carb, 1.75" headers. Should put you squarely in 375hp/450tq territory. Redline/shift around 5800.

volvoclearinghouse
volvoclearinghouse SuperDork
6/24/16 11:14 a.m.

In reply to curtis73:

Excellent recommendations. Thank you. I don't know the intake CFM of the D3VE heads, but we also don't plan on spinning over 5000 RPM. We'll be limited to about 4800 in top gear, I think, based on the track and top speeds we typically see.

We really like the Edelbrock 625s we have, I'm sure they're leaving some on the table but we have them dialed in and they just seem to work. Perhaps removing the chokes and massaging the castings and throttle blades a bit could pick us up a few CFM there.

Good info on the pistons. The 88-92 EFI pistons seem to have the smallest valve reliefs (and thus the flattest tops) so it's either them...or there's some inexpensive aftermarket flat tops we could run. They have higher CH, though, so we'd need thicker head gaskets to keep compression down and make sure the valves and piston don't go bumpity-bump.

oldeskewltoy
oldeskewltoy UltraDork
6/24/16 12:42 p.m.
volvoclearinghouse wrote: In reply to curtis73: They have higher CH, though, so we'd need thicker head gaskets to keep compression down and make sure the valves and piston don't go bumpity-bump.

You may be able to have the top of the piston machined..... Depending on where the first ring sits, there is often a few thousandths that can be removed from a pistons crown......

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