GT350 Engine Refresh Time!

[honeybadger]

You could use the same strategy that OEM's use to prevent smoke from a high consuming engine - just stick a catalytic converter on and you'll never see smoke again ;-)

As for the consumption, have you talked to people who build and run race engines about it? It could be normal for cast iron sleeves and forged pistons. Particularly if there's no "relief" in the tune from full intake vacuum during engine braking - that puts a real load on the valve stem seals.

Heheh. But "muh free horsepower!"

On a serious note, I haven't reached out to Roush Yates/Watson yet to see what they're doing. This is a good point. I've been told a mechanical vacuum pump is likely the best step, but more research to do. It smokes the worst on first start up (burns oil like a 2 stroke). Once hot, no more visual oil burn. Engine just loves to be at full operating temp. Runs like crap when cold. Haha

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[olaosunt]

Figured I should give yall an update now that I have about 15 track hours on the new engine.

In short, it's bloody awesome. I can't quite figure out how to describe it to folks, but it just feels different. It not only has more power, but it feels smoother, nastier, and angrier all at the same time. You can sit at 8km rpm vs. shifting to a higher gear and not really have to worry. It just keeps taking it and asking for more.

It revs like an animal, pulls like a bull and sounds like 10,000 angry honey badgers .

On top of all that, I can literally push it as hard as I can and have yet to get engine oil temps above 265* with the new cooler. At vir it was an open lapping event and I pushed it as hard as I could for 40 straight minutes and it was like "meh, that all you got?"

Also far, no signs of oil starvation. I haven't seen the accusump have to come on yet (knock on wood).

It ain't all perfect, tho. It's definitely more high maintenance than a stock motor. The E85 makes it a bit more work, I'm constantly checking spark plugs, compression, etc. After every event since I'm the warranty now.

Lastly, it does burn a good amount of oil. It's a race engine, so not super surprising. But at about 1 quart a track day (with visible blue smoke), well we'll have some work to do to iterate on it.

I'm still researching, but so far it looks like it might be a rings issue. And it's not unique to my engine or even the parts Tim used. I've spoken with 2 other built FPCs that are seeing similar oil burn/smoke. I'll keep you updated as I dig in.

Thanks again for this pioneering build .
Do you think the difference from your stock engine could be due to the lighter rotating assembly ?
I know you also had a lot of upgrades to the top end but I am stopping at just the valve spring upgrade .
My engine is about to put back together after sleeving the block and I have to decided whether to use the lighter Callie rods like you did(I am also using the diamond pistons) or stick with Manley H rods like I had originally planned .
Do you know if the lighter rods are “stronger” ?

My application is different since my car has a 2.9 whipple .
Thanks

 

[honeybadger]

Thanks again for this pioneering build .
Do you think the difference from your stock engine could be due to the lighter rotating assembly ?
I know you also had a lot of upgrades to the top end but I am stopping at just the valve spring upgrade .
My engine is about to put back together after sleeving the block and I have to decided whether to use the lighter Callie rods like you did(I am also using the diamond pistons) or stick with Manley H rods like I had originally planned .
Do you know if the lighter rods are “stronger” ?

My application is different since my car has a 2.9 whipple .
Thanks

I'm thinking probably a mix of rotating assembly balancing and weight - more so the balancing. The Callie rods should be stronger since they're billet, but I doubt you'd have any problems with Manley H rods either. Remind me again on your piston/ring combo? I can get the details from Tim, but I'd suggest a different ring setup than I have. Justin and RGR tried a few different sets on a recent re-build (not mine) and said they had a hell of a time controlling oil getting past the oil ring.

 

[olaosunt]

Thanks.
The pistons are coated diamonds , stock compression (Voodoo specific ) . I don’t know the details of the ring set up but I will ask my builder .

The Callie rods would only be an $800 “upgrade “ so I am thinking I might as well if they are stronger and lighter .

 

[bauern]

Thanks.
The pistons are coated diamonds , stock compression (Voodoo specific ) . I don’t know the details of the ring set up but I will ask my builder .

The Callie rods would only be an $800 “upgrade “ so I am thinking I might as well if they are stronger and lighter .

Answered your PM, but when you say pistons are Voodoo specific, is that with the .827 Voodoo piston pin? The Callies rod uses the Coyote pin size.

 

[Strokerswild]

I've been told a mechanical vacuum pump is likely the best step, but more research to do.

Vac pumps help quite a bit with ring seal, especially with thin/low-tension rings.

I forget the numbers but we did engine dyno pulls on a friend's 430" SBC (Super Gas drag engine) back to back with and without a driven pump and the pump numbers were notably better. Oil control was too; even with header-drawn crankcase extractor breathers it was a little messy, but virtually puke free with the pump.

 

[olaosunt]

Answered your PM, but when you say pistons are Voodoo specific, is that with the .827 Voodoo piston pin? The Callies rod uses the Coyote pin size.

I confirmed the pistons have the .827 pistons pin size
It looks like Callies also makes a rod for those pistons .

Engine builder said the piston line can be bored easily if needed for the standard .866 coyote pin sizing .
After much back and forth and lots of great advice from experts on this forum I think I am just going to stick to the H beams as I had originally planned

 

[honeybadger]

Another update -

Spent 2 days at COTA this weekend in 98* degree Texas heat. With the hood vents and the upgraded oil cooler, I could not get this bloody thing to overheat no matter how hard I tried. Using second gear, sitting north of 5k rpm, flat out and it would only hit 273 oil temps and 232 CHTs. Absolutely nuts.

As predicted, engine smoked a good bit on start up, but cleaned right up after the first session. Seemed to burn a little less oil this trip as well.

For interested parties, did a clinder leak down test before the event and I saw all cylinders 5-11% with no indication of any leaking from the valves (all through the piston rings). Very happy with how it's wearing in. Plan is to send it back to Tim when I 25% or I take the car far enough apart I don't the need engine for a while (cage work, cough* cough*).

 

[JAJ]

...engine smoked a good bit on start up, but cleaned right up after the first session...

Sounds like the smoke is a feature, not a bug. The engine clearly likes being hot. How are the gearbox and diff temps doing?

 

[mrbillwot]

Another update -

Spent 2 days at COTA this weekend in 98* degree Texas heat. With the hood vents and the upgraded oil cooler, I could not get this bloody thing to overheat no matter how hard I tried. Using second gear, sitting north of 5k rpm, flat out and it would only hit 273 oil temps and 232 CHTs. Absolutely nuts.

As predicted, engine smoked a good bit on start up, but cleaned right up after the first session. Seemed to burn a little less oil this trip as well.

For interested parties, did a clinder leak down test before the event and I saw all cylinders 5-11% with no indication of any leaking from the valves (all through the piston rings). Very happy with how it's wearing in. Plan is to send it back to Tim when I 25% or I take the car far enough apart I don't the need engine for a while (cage work, cough* cough*).

I was at track attack last week - it was high 90's and with 20 min on 20 min off track all day including insane hot laps by the pro's the stock GT350's seemed to not care about temps - most seemed to be MY16's & 17's (G & H dashplates).

 

[honeybadger]

I was at track attack last week - it was high 90's and with 20 min on 20 min off track all day including insane hot laps by the pro's the stock GT350's seemed to not care about temps - most seemed to be MY16's & 17's (G & H dashplates).

Those aren't pushed very hard, tho.

The GT350 does handle heat very well, don't get me wrong. But give me a stock car in yesterdays conditions and I'll have it in limp mode in 20 mins no problem. Did it last year at the same event.

 

[mrbillwot]

"Those aren't pushed very hard, tho. "

I dunno - 2.1mile road course in the desert & you've got amateurs so reving out in 3rd to avoid 4th on straights - not exactly a stroll (we did have cool down laps at the end of each session - the race prep'd Boss302's were getting hot the 2nd day).
And for hot laps, at least the ones I was in, we were drifting though chicanes in 3rd & 4th WOT.
YMMV

 

[honeybadger]

"Those aren't pushed very hard, tho. "

I dunno - 2.1mile road course in the dessert & you've got amateurs so reving out in 3rd to avoid 4th on straights - not exactly a stroll (we did have cool down laps at the end of each session - the race prep'd Boss302's were getting hot the 2nd day).
And for hot laps, at least the ones I was in, we were drifting though chicanes in 3rd & 4th WOT.
YMMV

Sure the instructors can push them, but the majority of students don't. I've driven UMC a couple of times. The short courses are very easy on the cars. You don't spend a whole bunch of time above 6.5K rpm. UMC is smooth, predictable, and safe (part of the reason its chosen for the school).

The school cars don't live easy lives for sure. But between the safe track and the street tires, they're not pushed super hard. Big difference in wear and tear on the car when running a street tire like Super Sports and a racing slick.

 

[mrbillwot]

Sure the instructors can push them, but the majority of students don't. I've driven UMC a couple of times. The short courses are very easy on the cars. You don't spend a whole bunch of time above 6.5K rpm. UMC is smooth, predictable, and safe (part of the reason its chosen for the school).

The school cars don't live easy lives for sure. But between the safe track and the street tires, they're not pushed super hard. Big difference in wear and tear on the car when running a street tire like Super Sports and a racing slick.

It's a shame they're moving to Charlotte (UMC hosting Ford is over after October).

 

[The Chairman]

HB passed me at speed Friday at COTA. That thing screams! Sounds like a pure race car....

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