Homebrew 2.4 Waterboxer

[jberger]

Folks,
Thought I'd throw my info into the mix. It all started about a year ago when I noticed a dpr 82mm crank sitting on a back shelf of my local shop. I thought what can I do with this??! I ended up using 96mm QSC shaved top pistons with stock length Scatt rods, stock style AMC heads with TRW valves, CB 2252 Cam (which I have already run in a bone stock 2.1 build using OE pistons and liners).

This combo was headed for sky high compression numbers... not much I could do. With a step cut in the head I was able to keep the static and dynamic ratio just below that of a stock DJ code lump. As such I thought I would give the porsche 1mm piston squirters a try at keeping the pistons cool, so adapted them to the case.

Other details- Deves rings, Stock cylinders bored to 96.05mm, schadek 30mm pump, pick up tube mod similar to 10C but with interference fit instead of o-ring, .040" copper head gaskets (annealed prior to install), 1.25/1 ratio rockers, stock hydro lifters

I have built dozens of stock air and water cooled engines and this one has given me an ulser.. worrying about every little thing. That said, I now have 100 miles on it and am beyond impressed. She sits in my wife's '86 syncro westy with 215 15 tires and stock gearing. I had an AA 2.2 stock compression top end in the previous power plant and this feels worlds different. Infact, I built a GW 2.3 "kit" for a friend a couple years ago that feels like a 1.9 compared to this. I live in an area that has hills that are over 12% gradient and i'm cresting hills in 3rd with partial throttle that I previously crawled up in 2nd mashed to the floor.

Now I know this may be very short lived due to the high compression. If it grenades in the next few hundred or thousand miles I'll build the same thing again only with some JE blanks with higher pin heights for a BIT lower compression. So far it has no perseivable ping, and I'm not the kind to drive around with my fingers stuffed in my ears.

[Zeitgeist 13]

Any info to share regarding your Porsche squirters?
_________________
Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[r39o]

Good luck with this.....

I have had a few similar Type iV engines grenade.

Not because of simple stuff like melting down a piston, but weird stuff.

Broken parts mainly which attest to the crap we have been getting these last years.

EX: Driving down the freeway at the speed limit and the crank breaking.
Or rocker parts failing.

Just weird stuff.....

Have fun!
_________________
"Use the SEARCH, Luke" But first visit the Vanagon FAQ!

1990 Multivan EJ 22, Rancho trans 0.82 4th, Small Car front AC, CLKs w/ 215/65-16, homemade big brakes 303mm, Konis, Recaros, etc....

Click to see my ads for Cup holders, Subaru clutch fix and CLK wheels (no wheels currently)

[presslab]

So your static CR is around 10.5:1? What octane are you running? Did you have to reduce the ignition timing?
_________________
1986 Vanagon Westfalia EJ25
1988 Subaru GL-10 EJ20G --- 2000 Honda XR650L
2010 Titus El Guapo --- 2011 On-One 456 Ti

[jberger]

[jberger]

[boof1306]

Hi Jberger, I am half way through exactly the same build right now. How much did you shave off the qsc's? Did you do any clearancing at bdc? Did you knock back the timing in response to detonation or just playing it safe? I am currently debating cam choice. I have a 2280 here which I am not sure about fitted as it gives me quite high dynamic compression and cylinder pressures just over 200psi. If you are getting good or should I say great performance with a 2252 I might have to get one in and play it safe. Greg

[boof1306]

Ahhh, just re read your post and realised you have ratio rockers. Now I am all confused again. Do you know what effective degrees your intake valve closes with the 1.25 rockers? Greg

[jberger]

[boof1306]

Yeah, I think that makes sense in that the hydro cams spec cards are measured at 0 lift and the others at 50 thou. I am relieved to hear you got a figure of 40 at .050", as that doesn't put the 2280's 36 degree close out of the realms of possibility. Were your qsc jugs out of round? I am also using the scat rods. I wish I hadn't as their bearing cap has a central ridge which lines up with the bottom of the 96mm pistons. I cleaned up the casting ridge on the piston to provide some clearance there. I also machined back that ridge at the bottom of the cylinder bores in the cases. One cylinder I think it was number three has that extra web down the bottom, that needed a bit more taken out. I have yet to check for crank-rod-cam clearance but the crank with rods spun freely in the case. I have gone with a cut of .070" and am still waiting on the pistons to come back. So glad to here you are happy with the power, I would hate to do all this for not much gain. It just goes to show how much more power gowesty could get out of their engines if they got serious about compression ratio. Thanks. Greg

[jberger]

[Zeitgeist 13]

Do you have a oil pressure gauge? I'd be curious to see how the squirters impact pressure under a few scenarios. I'm really intrigued with the idea.
_________________
Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[jberger]

[jberger]

I thought I would post another follow up of this 2.4 experiment.

I built a temp replacement powerplant to swap out and inspect the 2.4. It has run beautifully from day one, except an oil consumption issue (more on that later). The temp engine is loosely based on a 10c 2.2. This one is actually a 2178 with AA 95.5mm jugs, longer rods, trimmed pistons, a 2280 Eagle cam and some mild head work. The idle is a bit lumpy.... but What a GREAT little engine. It rev's out more freely then my 2.4 did and holds Almost as well up the hills. I have a test hill in my hood that is used to determine performance. Always in 3rd, I roll on the throttle from 30mph at the very bottom and see how it crests. The 2.4 would pull out to about 3800rpm and drop to about 3200 at the VERY steep top. This little guy will bust out to 4000rpm but is just a bit under 3k at the top. For comparison, an empty tintop syncro that I converted to EJ22 subie will only rev out to 3500 and is below 3k at the top.

Back to the 2.4..
I pulled the heads, cyls and pistons. Thinks look ok, just carbon'd up. I thought I would see some damage on the pistons from the abuse I've put it through.. but not even a mark. This thing has been going through oil pretty bad, 1/2 a quart every 200miles.. Less if I baby it, more if I don't.

I mic'd the cylinders and they are all still within .0001" (one tenth of one 1000th) of each other, in taper and round.
I also checked the ring gaps.. Interestingly, when new the top and scraper rings had .012" gaps, now they are all .018", some middle rings a bit bigger.
These were Deves rings and interestingly enough at the last moment I swapped in the QSC oil control rings (hastings single piece type with expander spring) due to fit issues with the Deves set, twice. The oil control rings have .025"+ gaps, they were not checked at install.

#4's rings looked to be aligned on the bottom of the cylinder... all others were still staggered.

I am planning to put it back together with the 2280 cam instead of the 2252 and the same head work that I did to the 2178.. but need to sort out if I actually have a ring issue, or.....