Porsche lifters in 36hp case solved?!

gimmesomeshelter

I was glancing at a friend's copy of Hot VW's Jan' 2015 issue, and it looks like Darrell Vittone was able to install Porsche lifters in a 25HP case. I tried buying a copy from some of the local auto parts stores, but it looks like most of them have stopped carrying magazines. Has anyone read the article? If so, does it show how he did it?

Cheers,

Paul
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RareAir · Posted: Tue Dec 09, 2014 12:15 am Post subject:

The 25/36hp lifter bores are sleeved with a Bronze bush. Then the bushing is bored to size for the Porsche lifters. I believe the engine also required custom length push rods which were supplied by BugPack (for this particular build)
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Mr. Motorhead · Posted: Tue Dec 09, 2014 10:21 am Post subject:

Anything is possible when you have cubic dollars to invest. Been done before so it's nothing new. From what I observed of the car running it sounded real good.
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Mr. Okrasa

OMT · Samba Member Joined: January 18, 2004 Posts: 296

Good post Joe,
Glad to see you're opening up.

fcampbell356 · Posted: Mon Dec 22, 2014 3:46 pm Post subject: Porsche cam & Lifters

Joe:

What would be the effect of using a Porsche 3-piece case type camshaft

with the 2 piece case lifters? In a 36hp case. Of course machining the

cam bore to accept the Porsche cam.

Frank

mark tucker · Posted: Wed Dec 31, 2014 7:01 pm Post subject:

Im no exspert on this but ...does the porsche have the lifters at an angle? probably not, same as the vw I suspect.but it's a raidi kinda like a roller cam. so all that is needed is to do the bush job and use the proper camshaft or else you will have somewhat less duration. or in this case going from raidi to mushroom you get more duration. just as you do if you change roller lifters that have a bigger roller, it contacts the ramp sooner. but I could be way off hear as I have been 7 times now. I do have roller cam vw's&v8's the cam lobes are much wilder looking . and to use a cam lobe like that you need either a roller or a mushroom.I gess the mushroom won out in this fight. there are many way to skin a cat. I have the article but havent read it all as of yet.

Mr. Okrasa · Posted: Wed Dec 31, 2014 8:16 pm Post subject: Re: Porsche cam & Lifters

slalombuggy · Posted: Wed Dec 31, 2014 10:46 pm Post subject:

As long as the top and bottom edges of the lifters are equidistant to the centerline of the cam it will not matter that the lifter bores are at an angle in the case. As far as longevity. I don't think that is a true concern in an LSR motor where HP is the only true measure of success. I agree that it was one of the wickedest sounding engines out there this year, certainly better than mine.

brad

Mr. Okrasa · Posted: Wed Dec 31, 2014 11:57 pm Post subject:

vwnc · Samba Member Joined: March 07, 2002 Posts: 173

On 36 hp lift bores, I talked with Brothers VW Machine Shop and they claim than can re-sleeve 36 hp lift bores and machine back to accept stock lifter. If this is the case, they are the first ones I've seen that offer this service. Has anyone had this done? My lift borers in block are really worn.

Mr. Okrasa · Posted: Mon Jan 12, 2015 3:34 pm Post subject:

latenightaircooled · Posted: Mon Jan 12, 2015 8:26 pm Post subject:

I believe Mr. Okrassa is correct, and you could prove it for yourself if you have made this modification by degreeing the camshaft in with the #1 cyl. and then the # 3 cyl. You will find cam timing on the 3/4 side of the 36 eng. will be retarded, compared to the 1/2 side. Juan
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fcampbell356 · Posted: Tue Feb 10, 2015 2:07 pm Post subject:

So, after reading the replies in this thread, what would be a choice for a camshaft in a 36hp case with profile of a 1500S Porsche engine?
Of course using Pre A lifters.

Anyone?

gimmesomeshelter · Posted: Wed Feb 11, 2015 2:50 pm Post subject:

Get the flow numbers for your heads and call Dema Elgin. He'll be able to make a cam that fits your engine.

Here's an article about a shop that worked with Mr. Elgin. http://www.willhoitautorestoration.com/1500_super.php

Cheers,

Paul
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HBH72 · Posted: Fri Apr 17, 2015 10:41 am Post subject:

Interesting topic – I have also made some thoughs on this one.

Changing the 36HP cam follower from radius tappets to flat tappet may very well go wrong:

A: the shape of the cam lobe. The cam is designed for either radius or flat tappet follower - not both.
B: the cam followers angle. All radius followers (2 piece 36 HP case) is placed at a slight angle. All flat tappets (3 piece 356 case or VW 40HP 2 piece case) are placed in same horizontal line as the cylinders.

So no VW or Porsche engine case is originally designed with flat tappet cam follower placed at the slight angle (as on 36HP 2 piece case).

Below is from a 1960 VW tuning book by Henry Elfrink, where he writes about this:

Image may have been reduced in size. Click image to view fullscreen.

Teeroy

Other than a timing difference on opening and closing, what other issues or problems would occur running flat tappets at the increased angle to the cam?
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HBH72 · Posted: Sat Apr 18, 2015 1:38 am Post subject:

Placing the cam followers at a slight angle (not horizontal with cylinder line) should not affect the overall valve opening time.

However, it must have very little influence on the excact valve opening and closing points (left side being a little too early and right side a little too late).

But that must be the same situation whether the cam follower is a radius tappet or a flat tappet ! And proberbly why the design later were changed, separating the pushrod and cam follower - to be able to get the cam follower positioned at 180 deg above each other (horizontal with cylinder line).

Anyway, the only reason for changing the cam followers in a 36HP case to flat tappet type ones, is when also changing the camshaft - to eventually a 356A camshaft (which is designed to work with flat tappet followers) - right..?

PS: has anyone ever made bushings for flat tappet cam followers, in a 36HP engine case, in a way that allows the cam followers to be positioned in straight horizontial line..?

earthquake · Posted: Sat Apr 18, 2015 9:46 pm Post subject:

Is there room for a roller cam in a 36hp case, I think a Harley Sportser has a roller lifter body that not very big in diameter but the roller is fairly large.

Casey
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