We are currently running on the new domain and server: www.Speed-Talk.com

IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/
(Right-click the URL and select "Bookmark this link")

Wrong direction on stroke

General engine tech -- Drag Racing to Circle Track

Moderator: Team

swampbuggy
HotPass
HotPass
Posts: 1107
Joined: Mon Apr 04, 2011 8:54 pm
Location: central Florida

Re: Wrong direction on stroke

Post by swampbuggy » Fri Mar 20, 2020 10:05 pm

Pankl con-rods maybe ? Mark H.

Little Mouse
Expert
Expert
Posts: 594
Joined: Mon Oct 21, 2013 8:48 pm
Location:

Re: Wrong direction on stroke

Post by Little Mouse » Sat Mar 21, 2020 7:30 pm

Some like to use steel rods others like to use aluminum, pankle rods were mentioned. Forgot to mention block is compacted graphite. Main caps 8620 steel. They feel billet aluminum blocks not cast aluminium would give them as much not flexing as the iron block, but NHRA wont let them use it. Kind of laughable if that's to save money in a corporate sponsored new world they have to live in.

dwilliams
Guru
Guru
Posts: 1123
Joined: Sun Oct 15, 2006 10:00 am
Location:

Re: Wrong direction on stroke

Post by dwilliams » Mon Mar 30, 2020 7:14 pm

Herb Adams destroked a Pontiac 400 to 303 CID to meet SCCA class limits in the late '60s. It used a 2.84 inch Moldex crank and 7.08 inch Carrillo rods.

User avatar
midnightbluS10
Expert
Expert
Posts: 843
Joined: Sun Oct 20, 2013 8:41 am
Location: Shreveport, LA

Re: Wrong direction on stroke

Post by midnightbluS10 » Tue Mar 31, 2020 2:17 am

Little Mouse wrote:
Fri Mar 20, 2020 8:12 pm
Been reading about the new DRCE4 pro stock block and what there doing in pro stock. Ya the mains are the old 409 size 2.5, rod pins are Honda size 1.888. Cam can be from 70 to 80 mm. The 80 mm is 16 mm bigger the mains on the crankshaft, has 9 jurnals supporting it, compression rings are either stainless steel or carbon steel .021 with a titanium nitrate coating, oil ring 2.00 mm. Oil viscosity they use W02. Deck height as block comes 8.90 can be cut up to .300 lower. Crankshaft is 50lbs and I forget the mandated rule on the piston, pin and rod. Think the piston was 430 grams, pin 130 grams. Original bbc took somewhere in the 25 to 35 lb range to turn the rotating assembly. They only need an inch pound tq wrench to check theres. They have some special tool to check cylinders for roundness to 1 micron. All of GMs DRCE4 blocks and there nascar block are made by a company over in england or there more proper, united kingdom. Lol
If you want to do some reading, there's a 'Pro Stock Tech" thread in the NA forum at yellowbullet.com that's a known hangout for a few pro stockers. Engine builder Nick Ferri, what's his name from Madcap that goes by 'goneracin' , and one or 2 others. They regularly talk about pro stock tech there. Lots of good info in the 300+ pages of replies

https://www.yellowbullet.com/threads/pr ... 0/page-300

And afaik, RMS was the first to do that crank in that block. They were running 362ci big blocks in pro stock before anyone was running that combo anywhere afaik.
JC -

SUPPORT THE RPM ACT :!:

https://www.sema.org/rpm-bill-summary

Little Mouse
Expert
Expert
Posts: 594
Joined: Mon Oct 21, 2013 8:48 pm
Location:

Re: Wrong direction on stroke

Post by Little Mouse » Wed Apr 01, 2020 10:11 pm

So I'm curious how did they do it, make spacers for the mains and how is that even done.

tenxal
Expert
Expert
Posts: 658
Joined: Sun Nov 17, 2013 8:48 pm
Location:

Re: Wrong direction on stroke

Post by tenxal » Thu Apr 02, 2020 2:00 pm

Little Mouse wrote:
Wed Apr 01, 2020 10:11 pm
.....make spacers for the mains and how is that even done.
It's no different than putting a small journal crank in a big journal (non 400) SBC block. Most use an old set of bearings and hone them to fit the new small journal bearings.

Warren Johnson did much of the early 348 crank/BBC Pro Stock engine development, along with RMS. These engines were also very popular in the Comp and Modified classes.

Post Reply