Motor Porn

[DanStokes]

Maybe this goes in Tech - or Project Cars, but I'll stick it here for now.

Randal asked me to post pics of my Chevy six Crower rods when they got here and I decided to wait for the Ross pistons and post the whole deal, so here goes.

Six cylinders are NOT cheaper to build as I'm pretty sure I paid the same for 6 sets of what follows as you 8 cylinder guys would pay for 8 of 'em. But I always seem to build the weird stuff so here's one more example.

Dan

Anybody know how to rotate a pic?

[1Y]

I count 6 spots for pistons, but 8 rod boxs. Did you have to buy a set of 8 or did you purchase 6 and 2 empty boxs? What did you give for those 6 Ross Pistons and I'll tell ya what I got in a set of 8.

[TheSilverBuick]

Ooh, those all look real pretty! Thanks Dan.

[TC]

Nice Dan!!!!!!

But what, no coatings??

[67pete300]

Drool!

Boost!

[BigBlockMopar]

Almost too nice to hide inside an engine... :o)

[OldMachinist]

Isn't it nice to build an engine with nice parts. Are you using the stock cast crank or do you have a forged one? Is that a 250 Chevy with the same rotating assy. as an OHC Pontiac? Hint hint Randal.

[Bob Holmes]

Early Christmas!!! I really enjoy opening up those kinds of boxes.

[DanStokes]

Yep, 2 extra boxes to fill out the big box. I guess they sell more sets of 8.

I got a pretty good deal on the pistons but still they were $565 w/shipping from Tom Lowe.

Pete - I'm building with the idea of being boost or N2O compatible.

No coatings because I had to cut SOMEWHERE! Still, the pistons came with Total Seal rings. I haven't used them before but I like the concept.

Dan

[Stich496]

you'll love the rings..
coatings are overrated for what you planning on..

[TC]

Still, the pistons came with Total Seal rings. I haven't used them before but I like the concept.

Dan

You will love them, I've ran them in a couple of motors.....On a 350 I had with a Crane Cam with 296/304 duration the motor would pull 12" of vacuum.......

[DanStokes]

I didn't answer the crankshaft question, did I? Here's the deal - I'll look at what I have and pick the best one. Cranks are not much of an issue on these engines as they have a main between each rod journal and the crank does not tend to move much. Cast or forged is OK and I don't think there are many if any forged 250 cranks - those seem to be mostly for 292 truck engines. Although Brian may have one.

I'll also be doing my own lump port job. Tom Lowe (one of the inline Chevy six gurus) has a new style bolt-in lump that I plan to use and they're pretty straightforward to install if you have a die grinder and a Sawsall. I'll have to find someone with a Bridgeport (or similar) as there are 3 holes to align drill, but other than that I can do it at home. I have roller rockers, some small wire diameter springs (to avoid coil bind) and a decent flat tappet cam from Delta that will find it's way into the engine as well. About all I'm missing for the valve train are a new set of valves - the oversize ones I have are TOO BIG.

Tom has done quite a bit of dyno testing and he's sure I'll get at least 300 HP, which will be a big uptick for me. Pretty soon I'll have to get back on the safety stuff as that much HP should send me into the next safety category.

Dan

[OldMachinist]

I didn't know if you were using forced induction when I asked about crank but stupid me if I had just looked at pistons I would have realized CR too high for that. With blower driven from crank that small neck on crank wouldn't survive with cast.

[RustyRodder]

oooh, shiney! cant wait to see it together.


I hear you on the 6 parts- you would think being 2 less, they would be less coin!

[DanStokes]

Actually, the pistons are forged and overall CR should be about 9.5:1. I do eventually want to turbo it but I'll stay with 7-8 lb of boost.

The cranks in these motors are TOUGH. The "fuse" in the engine is the pistons, followed by the rods. While I suppose it's possible, I've never heard of anyone killing a crank in one of these unless it's a bearing surface failure. But no catastrophic failures. BTW - the crank nose is the same as the SBC (for example, they use the same vibration dampner) so I'd expect it to hold up OK with a blower drive. But it's a turbo for me - someday.

In fact, the 250/292 share a lot in common with a SBC. The valves, springs, and other bits interchange. Other than the big end width the rods are the same. 283/307 pistons will work. I guess Chevy figured there was no sense in reinventing the wheel.

Dan