Can you change the cam with engine in car?

[rponfick]

I have a late MK 4 with a 351 W engine. The original owner installed a flat tappet cam and I would like to convert it to a roller. Is that a fairly easy chore without removing the engine?

Thanks, Ralph

[Gordon Levy]

Yes but it is tight. You may need to raise the engine slightly to clear the X brace.

[rponfick]

Any others have comments on their experience?
Thanks, Ralph

[Railroad]

Just start pulling the front off, you can adjust as you go. Nothing lost, if you have to pull rad or raise engine.
You might see how the new cam fits, length wise in front of the engine, should give you an idea. Be sure to loosen the trans mount if you need to raise the front of the engine.

[drewr]

The main thing is you need a straight shot into the hole. You don't want to be banging the cam lobes against the innards trying to seat the camshaft home. You also don't want to ding or knock one of the cam bearings loose. This is kind of hard because the shaft is heavy. Some shops use a weighted attachment on the end of the camshaft to keep it balanced as you guide it home. I guess it could be done in the car, but you'd have to be careful. Way easier on an engine stand.

[drewr]

I was commenting on installing a new camshaft. In order to make a flat tappet cam engine into a roller, you'll have to tap the engine valley to hold the "spider" in place. You can google it if you don't know what I'm talking about. But drilling and tapping in an engine block will generate metal shavings which will be a big no no for a working engine. So you pretty much should learn to love an old skool flat tappet cam. Or start over with a roller block. Guys can correct me if I'm wrong, but I'm not sure you can do everything you need to do to convert a Ford engine to a roller cam while its still in the car.

[jts359]

I did it a couple of years ago , Its tight but I did it , Ed

[Sdonnel]

It can be done. I found that the radiator does not need to be pulled. Once you have it about 25% into the engine block, thread a 6 inch bolt into the end of the camshaft (thread needs to be determined) to give you leverage to prevent banging the lobes on the bearings. I also used the bolt to remove the camshaft as well. Just have to pull it off before hitting the radiator.

[ggunter]

If you install a roller retro fit, there is no block tapping. The lifter guide bars keep the roller tappets straight.

[Norm B]

The camshaft is a little heavy and awkward to instal reaching over the body. You might need two different lengths of installation tool. I found that I could get the cam into the block so that the third race on the cam was in the front cam bearing. I then had room to instal the tool and finish the installation.
A already stated, make sure your block is already setup for a roller cam before going through the installation process with the engine in the car. If the block needs to be drilled and tapped for your lifter setup then that should be done with the engine removed.

[Railroad]

I think you are wrong. The spider lifters are not the only option. Without checking, I feel sure you can run link lifters, no spider, no drilling.

https://www.summitracing.com/parts/mel-f1900rf16

[jab351w]

Regarding 351W roller cam compatibility, there are two basic flavors of production 351W blocks, 1994 and later blocks with tall lifter bores that can accept a standard roller cam with "regular" non-link bar roller lifters and earlier blocks with short lifter bores that were originally intended to accept a flat tappet cam and lifters. The '94-up blocks should have an engineering casting number starting with "F4TE" and will already be drilled/tapped for the lifter spider required to keep the regular roller lifters from rotating. If you have a pre-'94 non-roller block, there are two options for running a roller cam: link bar lifters with a standard base circle roller cam, or regular roller lifters with a "retrofit" small base circle roller cam. If using a retrofit cam in a pre-'94 non-roller block, the block will also need to be drilled/tapped to accept the lifter spider.

Hopefully that clears up some of the confusing and incomplete info in this thread. Note that the above only applies to production Ford 351W blocks, I can't speak to aftermarket blocks.

[drewr]

Thanks. I forgot about the link bar lifters. I hear they work well. Makes me nervous to think about more moving parts, but I haven't seen anything to say they aren't a good solution. People have put them in Mustangs for years, even drag race with them. I guess if we're talking about a weekend driver with low stress, it doesn't matter. We're not talking a racing engine. But in that case, why bother? IF your engine needs a top end redo, or you just want a different cam, then sure. Anyway, it sounds like it's all possible. Good luck!

[rponfick]

I have a 1971 block, so I will have to use the retro roller kit with the roller lifters linked together. I would not consider tapping for stock style lifters.
I have posted another post with my idea to remove the engine. After further thought, I think I will pull the engine.
Thanks for the thoughtful comments and experiences.
Ralph

[Railroad]

Just confirming, you will have to upgrade your valve springs. The heads will probably come off, without pulling the engine, unless you have head studs.