[RAIV-Z]

Originally Posted by Scott Stoneburg

Why did you switch to a shorter stroke? For durability or will it make more power with the shorter stroke?

Less stress on internal parts, with more RPM. I don't think we were at the limit of power with the 4.5 stroke yet, but we were out of RPM. The majority of current big power power boosted Pontiac are in the 480 to 500cid range.

[GTOGEORGE]

Originally Posted by RAIV-Z

Less stress on internal parts, with more RPM. I don't think we were at the limit of power with the 4.5 stroke yet, but we were out of RPM. The majority of current big power power boosted Pontiac are in the 480 to 500cid range.

Be a leader not a follower!



GTO George

[[email protected]]

How high do you spin it?

[Stan Weiss]

Originally Posted by GTOGEORGE

Be a leader not a follower!



GTO George

What stroke is in Tommy Youmans engine?

Stan

[GTOGEORGE]

Originally Posted by Stan Weiss

What stroke is in Tommy Youmans engine?

Stan

Don’t know.........why?



GTO George

[cgeise]

I was running over 8k with 4.5 crank -- just fyi

[[email protected]]

George how how do you twist yours up?

[GTOGEORGE]

Not very......I’ve had it 7,200 rpm but with my fuel situation anything over 6,800 is a waste. I wonder the stroke of those 900+ cubed No Prep and Pro Mod engines!


GTO George

[Stan Weiss]

Latest NKRA rule book I have is 2017. The supercharged and turbocharged Pro Mod engine have a max size of 526 ci Turbocharged and supercharged entries are limited to a maximum bore center of 4.800.

Stan

[RAIV-Z]

Originally Posted by GTOGEORGE

Be a leader not a follower!



GTO George

I'm trying George, but it's not cost effective to reinvent the wheel. We will all go faster if we learn from one and other.

[RAIV-Z]

Originally Posted by Stan Weiss

What stroke is in Tommy Youmans engine?

Stan

Tommy is running a 505cid engine, 4.25 stroke.

[RAIV-Z]

Originally Posted by cgeise

I was running over 8k with 4.5 crank -- just fyi

Soft rev limit was 7800, hard 7950. Heavy billet counterweighted crank and steel rods.

[RAIV-Z]

Originally Posted by Stan Weiss

Latest NKRA rule book I have is 2017. The supercharged and turbocharged Pro Mod engine have a max size of 526 ci Turbocharged and supercharged entries are limited to a maximum bore center of 4.800.

Stan

Another good point regarding engine size. Not that the Raven is a ProMod

[GTOGEORGE]

Originally Posted by RAIV-Z

I'm trying George, but it's not cost effective to reinvent the wheel. We will all go faster if we learn from one and other.

If the wheel wasn’t reinvented at least thousand times it would still be stone and it would have an e headed engine


GTO George

[mgarblik]

Huge number of changes/up-dates in one off season. Love to see all that work being done to go faster and be more reliable. Dedication right there. I personally like the 482-500 Cu In. package better than the longer stroke, but allot of expense to make the change. What RPM's were you turning with the 4.5" arm? Any issues, or just a cautious change to push it harder in the future? When we ran the Grocery Getter with the 4.5" stroke, we felt we needed the extra cubes to get that very heavy car moving. You are probably 400 lbs. lighter than we were. Best of luck this year.

[Stan Weiss]

Originally Posted by RAIV-Z

Tommy is running a 505cid engine, 4.25 stroke.

Ed,
Thanks. I knew the answer, just wanted to see what George would say. LOL

Stan

[GTOGEORGE]

Originally Posted by Stan Weiss

Ed,
Thanks. I knew the answer, just wanted to see what George would say. LOL

Stan

.........about what?



GTO George

[RAIV-Z]

Originally Posted by GTOGEORGE

If the wheel wasn’t reinvented at least thousand times it would still be stone and it would have an e headed engine


GTO George

I don't think the concept of the wheel has actually changed much over time.

[RAIV-Z]

Originally Posted by mgarblik

Huge number of changes/up-dates in one off season. Love to see all that work being done to go faster and be more reliable. Dedication right there. I personally like the 482-500 Cu In. package better than the longer stroke, but allot of expense to make the change. What RPM's were you turning with the 4.5" arm? Any issues, or just a cautious change to push it harder in the future? When we ran the Grocery Getter with the 4.5" stroke, we felt we needed the extra cubes to get that very heavy car moving. You are probably 400 lbs. lighter than we were. Best of luck this year.

Thanks Mike,

Yeah, some updates were due to broken/worn parts, the main driver for changing the crank at this time was the need for pistons. To clean up a few of the bores we needed to go 0.010. The shorter stroke and aluminum rods will give us additional RPM head room as well as reliability. There were no major issues with the engine aside from the cracked damper hub and some signs of cracking on the cam key way. We're also replacing the keepers and retainers based on Victory's assessment of the valve train, they indicated we had few retainers where the taper was opening up. We did drop an intake valve last July. Victory suggested their Ti-17 retainers and associated keepers. The valves are also being lightened and we're performing a valve job.

We were keeping the rpm under 8000 with the 4.5 stroke. Did the Grocery Getter weigh over 4000lbs?

[slowbird]

Originally Posted by GTOGEORGE

Be a leader not a follower!



GTO George

Says the guy with a roots blower and carbs. Leading edge tech for 1940