pushrod tubes for long stroke

vw eats v8s · Post by **vw eats v8s** » Tue Jul 18, 2000 6:45 pm

I'am in the process of assembling a 78 stroke type 4, the pushrod tubes are barely sealing and part of the oring is protruding from the head, due to the fact of a ,220 spacer to get compression where it needed to be. What is the deal here, how can zi do this and not have a leak? should I fab a splice in the tubes? should I fab a shim to go inside the pushrod tube bore to sopace the tube offset and allow more area in the head? does anyone make a tube for this applkication?

vw@micron.net · Post by **vw@micron.net** » Wed Jul 19, 2000 7:04 am

Did you select stroker pin height pistons? I would think you wouldn't need a ton of spacer like that with an "80 stroke" pin height.
Steve

CptanPanic2 · Post by **CptanPanic2** » Wed Jul 19, 2000 7:22 am

I need to know the same thing since I to had to use a big spacer, since normally on my 80mm stroker the piston was actually sticking out the top of the cylinder. So any information would be appreciated.

JohnConnolly · Post by **JohnConnolly** » Wed Jul 19, 2000 7:47 am

If it's only .250", the stock tubes will work. Clean the case and heads, and throw some Permatex silicone in the tube holes. Put the tube in, and tap it in, but do NOT push it all the way in. It's fine this way once the silicone sets up. You do NOT need the PR tube retaining springs.

If you have more than .250" spacers, you need to extend the tubes. Get two sets of tubes, make appropriate cuts, and braze em' together.

CptanPanic2 · Post by **CptanPanic2** » Wed Jul 19, 2000 8:35 am

So John with the silicon, you do not need the push rod retaining wire? This is because of the silicone?

JohnConnolly · Post by **JohnConnolly** » Wed Jul 19, 2000 9:16 am

correct. The wire retainer is a PITA to install (until you figure out how to make it easy). It's not needed when you use the silicone.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by CaptainPanic:
So John with the silicon, you do not need the push rod retaining wire? This is because of the silicone?<HR></BLOCKQUOTE>

vw eats v8s · Post by **vw eats v8s** » Wed Jul 19, 2000 2:37 pm

well, I have resolved the problem.and to all of you who say why do you need that type of shim, this is the scenario I was holding out for later to unveil this beast, but here's the sneak peek!!!!......I'm a certified powerplants tech for a major airline and have resources for some extraordinary parts.....this includes the 116mm pistons that were modified slightly and installed in my custom made cylinders.

I ended up needing .900 extra pushrod for my transplant. the cylinders used were from a 6 cylinder lycoming and adapted great to the t-4 rods, minimum of work was needed. the engine also has heads from a 4 cylinder continental prop engine, this is a full drag race engine and this amount of shimmage was needed to even get compression to 13:1....This is what I did.....

cut the pushrod tubes and fabbed a special fixture to hold them straight, with 3/4 emt conduit a sleeve was made and extended 1 inch either side of the splice point. I then brazed the two ends together and formed a leak proof sweat fitting, it is a piece of work and is very true.....keep in touch

GDRBO · Post by **GDRBO** » Wed Jul 19, 2000 3:13 pm

Thats 3381ccs or 206 cubic inches! I had a Mustang with a smaller motor.

JeffH · Post by **JeffH** » Wed Jul 19, 2000 7:10 pm

wow can I have one for my bus please
Jeff