Chevy 383 stroker build

[z 28 jari]

I have 385 sbc 10.6 static compression ratio with ported EQ vortec heads,running with E98 gasoline(same as US 93)no pinging or knocking issues.Max ignition advance ~35degrees.

[skinny z]

...running with E98 gasoline

I'd say that's a difference maker.
Wouldn't the added volume required for E98 have a noticeable cooling effect on the intake charge?
I would think so.

[z 28 jari]

...running with E98 gasoline

I'd say that's a difference maker.
Wouldn't the added volume required for E98 have a noticeable cooling effect on the intake charge?
I would think so.

It has 5% ethanol content,rest is hydrocarbons, aka pump fuel.

[skinny z]

...running with E98 gasoline

I'd say that's a difference maker.
Wouldn't the added volume required for E98 have a noticeable cooling effect on the intake charge?
I would think so.

It has 5% ethanol content,rest is hydrocarbons, aka pump fuel.

Fair enough.
In Canada, the number after the "E" indicates the % of ethanol to gasoline. E10, which is our typical pump fuel would have up to 10% ethanol.
I did edit this to correct myself.
51 percent to 83 percent ethanol blend would be E 85.


That is, if I have my facts straight.

[skinny z]

Having said that, 10.6:1, iron heads and success is pretty good in my books.
Cam specs on that? Seat to seat if you can.

[z 28 jari]

comp xfi280 https://www.compcams.com/xfi-230_236-hy ... r-sbc.html

[steve cowan]

Skinny, think the combo and issue you just listed would've been the same if the only change was iron Vortec to aluminum Vortec? That seems like it's asking a lot but I've never just made that single change.

I'm looking for chamber/piston ccs to get somewhere around 10.25 without stuffing volume into a crevis but those don't seem to come easy.

Rev,
I just got these pistons, I will be at 11.1:1 with my TFS double hump heads on my 880 roller block,6 " rods and Scat 3.75" crank.
They do a 16cc dish with my setup would give you 10.3:1
1.5, 1.5, 3mm ring pack there is no oil ring spacer and with the short skirt won't hang out of bottom bore.
$750 US from Summit 4 month wait.

20211231_123124.jpg

20211231_123114.jpg

[skinny z]

Rev,
I just got these pistons, I will be at 11.1:1 with my TFS double hump heads on my 880 roller block,6 " rods and Scat 3.75" crank.
They do a 16cc dish with my setup would give you 10.3:1
1.5, 1.5, 3mm ring pack there is no oil ring spacer and with the short skirt won't hang out of bottom bore.
$750 US from Summit 4 month wait.20211231_123124.jpg20211231_123114.jpg

That's the same 16 cc piston that was spec'd in the 383 build I was pursuing. (And still possibly might pending my shortblocks condition.)
That said, with a 64 cc chamber and .040" PTH clearance, I can only get to 9.8:1.
I was looking for a 12 cc piston and with my current chamber volume of 65.4 cc, I can get to 10.1:1. (Same 40 thou deck)

[RevTheory]

Rev,
I just got these pistons, I will be at 11.1:1 with my TFS double hump heads on my 880 roller block,6 " rods and Scat 3.75" crank.
They do a 16cc dish with my setup would give you 10.3:1
1.5, 1.5, 3mm ring pack there is no oil ring spacer and with the short skirt won't hang out of bottom bore.
$750 US from Summit 4 month wait.20211231_123124.jpg20211231_123114.jpg

That's the same 16 cc piston that was spec'd in the 383 build I was pursuing. (And still possibly might pending my shortblocks condition.)
That said, with a 64 cc chamber and .040" PTH clearance, I can only get to 9.8:1.
I was looking for a 12 cc piston and with my current chamber volume of 65.4 cc, I can get to 10.1:1. (Same 40 thou deck)

I was quite surprised that getting around 10.25:1 out of a 383 that's been done to death was such a hassle. You'd think you could get pistons off the shelf at whatever relief volume you wanted but it's apparently no-mans-land from 5 to 16cc. I dicked around in the chamber for hours and finally got it to 70cc so I guess I'm in business at ~10.35:1.

Steve, those look sweet. I like the skinny rings but I'm in a position where I can't wait 4 months. I think it was DSS that had some with 5 cc reliefs and a 3/16th ring that were actually in stock and about $450 if I remember right. I'll probably have to head that direction.

Edit because I'm dumb: 1/16th, 1/16th, 3/16th rings.

[skinny z]

Rev,
I just got these pistons, I will be at 11.1:1 with my TFS double hump heads on my 880 roller block,6 " rods and Scat 3.75" crank.
They do a 16cc dish with my setup would give you 10.3:1
1.5, 1.5, 3mm ring pack there is no oil ring spacer and with the short skirt won't hang out of bottom bore.
$750 US from Summit 4 month wait.20211231_123124.jpg20211231_123114.jpg

That's the same 16 cc piston that was spec'd in the 383 build I was pursuing. (And still possibly might pending my shortblocks condition.)
That said, with a 64 cc chamber and .040" PTH clearance, I can only get to 9.8:1.
I was looking for a 12 cc piston and with my current chamber volume of 65.4 cc, I can get to 10.1:1. (Same 40 thou deck)

I was quite surprised that getting around 10.25:1 out of a 383 that's been done to death was such a hassle. You'd think you could get pistons off the shelf at whatever relief volume you wanted but it's apparently no-mans-land from 5 to 16cc. I dicked around in the chamber for hours and finally got it to 70cc so I guess I'm in business at ~10.35:1.

Steve, those look sweet. I like the skinny rings but I'm in a position where I can't wait 4 months. I think it was DSS that had some with 5 cc reliefs and a 3/16th ring that were actually in stock and about $450 if I remember right. I'll probably have to head that direction.

I'm thinking the ideal route would be a flat top 5cc piston and a 72cc chamber. Summit lists 90 different head options.
Starting with a ~65 cc iron head isn't an ideal situation. As was mentioned, finding a piston with a volume between 7 and 16 cc isn't an off the shelf item. At least not from the usual sources.
One build direction is using the JE/SRP forged 16 cc reverse dome piston w/ 1/16, 1/16, 3/16 ring pack (SRP 138103) and cutting my heads down (yet again).

[F-BIRD'88]

KB197 piston. 383 5.70" rod -12 CC D dish. standard 5/64" ring pack. T6 Hyper. -12 Cc dish volume

[F-BIRD'88]

Or KB claimer piston 9912HC -13cc round dish.

[skinny z]

Seems to me I've come across those KB pistons but for whatever reason, it wasn't a suitable match. I'll have to dig through my notes. It may be that I had spec'd a 6" rod.
And a thin ring pack.
Forged as well.

[RevTheory]

Seems to me I've come across those KB pistons but for whatever reason, it wasn't a suitable match. I'll have to dig through my notes. It may be that I had spec'd a 6" rod.
And a thin ring pack.
Forged as well.

I had these on the back burner but I was trying to shy away from hypers in case I found myself needing to pull back some timing early on in the range.

https://www.summitracing.com/parts/uem-skb122-030

[rustbucket79]

Rev,
I just got these pistons, I will be at 11.1:1 with my TFS double hump heads on my 880 roller block,6 " rods and Scat 3.75" crank.
They do a 16cc dish with my setup would give you 10.3:1
1.5, 1.5, 3mm ring pack there is no oil ring spacer and with the short skirt won't hang out of bottom bore.
$750 US from Summit 4 month wait.20211231_123124.jpg20211231_123114.jpg

That's the same 16 cc piston that was spec'd in the 383 build I was pursuing. (And still possibly might pending my shortblocks condition.)
That said, with a 64 cc chamber and .040" PTH clearance, I can only get to 9.8:1.
I was looking for a 12 cc piston and with my current chamber volume of 65.4 cc, I can get to 10.1:1. (Same 40 thou deck)

Do you honestly feel that .3 of a point of compression is worth stressing over? That might be worth 5 hp. Might.