Oversized INA lifters in 8v motor install

[Mark2023]

Hey Car pokes,

Saw some members were interested in replacing their original lifters and thought I would share some of the work I had done. I initially began this endeavor after I had discovered deep scratches in one of my lifter bores when replacing my head gasket. I briefly considered having the damaged bore welded then re-bored to original spec but was told by multiple professionals that welding a bearing surface was a bad idea. This is when I contacted the machinist that had rebuilt my cylinder head. He is a 944 savant and a true car guy. When I first visited his shop he had dozens of 944 cylinder heads and a few blocks that he was working on, needless to say, I trust the man's judgment. He suggested performing a modification were he would expand the lifter bores from 1.496 to 1.575 inches to fit new INA 420 0001 100 lifters originally used in a 1991 Mercedes. These lifters are completely different than the remanufactured 944 INA lifters that have been widely condemned. Boring out the lifters is a very common modification on domestic vehicles and is currently being endurance tested in a few 944 race cars. In fact, when I went to drop off my cam tower he happened to be performing the same modification on another customer's tower; I believe this is becoming more common. After 32 years of faithful service, all of our bores are oval-ed and lifters clogged with sludge. Replacing the sealed lifters with serviceable and cheaper ($12) lifters is a win for the community of 944 enthusiasts. In my case, this was a far more elegant solution than buying a used and likely warn cam tower on the cheap. Now I am reassured that all the critical measurements for this cam tower are within spec (with the exception of the camshaft stuff). The new lifters did require the installation of lash caps. The purpose of this post is just to say it is possible with the addition of lash caps to use the INA 420 0001 100 lifters in a 944. I will link some photos and a video of my car idling with the lifters for those that are interested.

I do plan on going into greater depth on the installation and updating this thread with my experience with the new lifters. As of right now I have put 100 miles on them and am very happy with the results and added peace of mind.

FYI the video was taken on a cold engine, so a bit more lifter noise is expected under those conditions. I tried to vary the throttle a bit for the video.

(I could not upload the video to car pokes for some reason, I will work on that but for now here is a youtube link)

[gruhsy]

Fantastic
Thanks for sharing
I honestly thought this solution was going to be kept from the majority
Much easier solution than the route I am looking at.

[Mark2023]

Fantastic
Thanks for sharing
I honestly thought this solution was going to be kept from the majority
Much easier solution than the route I am looking at.

i’m really hoping that this goes main stream.

What options are you considering?

[gruhsy]

It’s the thread next to this one
My friends shop can make lifters for me but it’s a slower process as he does stuff for me when they are slow
He does stuff for me all the time no charge
It wasn’t really something I wanted to market either
Just wanted the option as shipping parts to the US is a pain and wasted money on imports/export and shipping

[Tom]

Mark, is this the same set up that @RUG8RB8 is referencing the thread below -- machined by "Spiro" and promoted by Joshua? Did Spiro do that machine work and fit the last caps etc right her in San Jose? Or is this a similar approach done by someone else? I'm generally not a pioneer with stuff like this, since real-word feedback often informs theories, but if it continues to prove itself to last on the street and track, it sure beats paying over $2,000 for a set of lifters!

viewtopic.php?f=4&t=52&start=40

[ihate944s]

Mark, is this the same set up that @RUG8RB8 is referencing the thread below -- machined by "Spiro" and promoted by Joshua? Did Spiro do that machine work and fit the last caps etc right her in San Jose? Or is this a similar approach done by someone else? I'm generally not a pioneer with stuff like this, since real-word feedback often informs theories, but if it continues to prove itself to last on the street and track, it sure beats paying over $2,000 for a set of lifters!

viewtopic.php?f=4&t=52&start=40

Do you have any theories?

[Mark2023]

Mark, is this the same set up that @RUG8RB8 is referencing the thread below -- machined by "Spiro" and promoted by Joshua? Did Spiro do that machine work and fit the last caps etc right her in San Jose? Or is this a similar approach done by someone else? I'm generally not a pioneer with stuff like this, since real-word feedback often informs theories, but if it continues to prove itself to last on the street and track, it sure beats paying over $2,000 for a set of lifters!

viewtopic.php?f=4&t=52&start=40

Joshua machined mine and I installed the lash caps that Joshua provided.

[AudiSport]

Looks like you have a nice clean 89 Turbo. Curious to see how these sound after some more miles and warmed up. They're pretty loud in that video.

[Mark2023]

Looks like you have a nice clean 89 Turbo. Curious to see how these sound after some more miles and warmed up. They're pretty loud in that video.

I took that video right after the install but waited a bit before I shared my experience online.

I think at the time of the video they still had some air in the lifters. After 100+ miles they quieted wayyyy down, I edited the original link to include the updated cold idle video I would guess at least 50% quieter.

[Tom]

Nice, thanks for the update. How many miles on them now? Have you got on it to redline, etc.?

As for the start-up ticking, take a big pickle jar and installed a barbed hose fitting in the lid. Put a lifter or two in the jar and pour motor oil in until the lifter(s) is fully submerged. Then put the lid on tight and draw a vacuum with a mityvac. You'll see the trapped air bubbling out of the lifters (and oil going in). At least with 944 lifters, you can virtually eliminate that initial lifter tick. Have to believe it would work just as well on these lifters because physics.