40HP freshair teardown - Verdict..

[remerus]

Hello Chaps,

I am currently in the process of tearing down the original matched number 40hp freshair motor to my 63 beetle as I had a few various leaks and thought it time to take it down to the long block and replace the 50+ year old seals and gaskets as well as have a look at how the cylinder heads and pistons were holding up. My intention at the moment is not to take the case apart if I can help it but to clean the motor up. there is no slop in the end float and the compression while not high was 100psi throughout (from what I have read on searching through the samba) still has life left in it.

A bit of background the car is complete and running and is used for a weekend cruiser and a hobby car really with the view to restore to stock down the track. the engine ran well with no smoke and no odd noises with decent power for what it is. the compression was 100psi throughout all four cylinders. the car was driven up to 300km straight on a couple of Sunday drives in the last month without a hiccup. the problem for me was the leaking oil. Other than that I want to do an overhaul on the 28pict carb and replace the manifold (purchased a restored one from Branston ) as it was rusted out on the right hand heat riser. Lastly to replace the leaking input shaft seal in the transmission that I missed when I did the rear main seal three months ago.

I started the teardown last night and got down to the head and cylinder removal this morning, Little bit afraid of what I found in the pictures... are any of these parts able to be reused or do I have a problem?

[Aussie63]

It's impossible to tell from just looking at pictures.

Your need to measure all the tolerances such as ring gaps with a feeler gauge. Check the cylinders for wear in the same manner and looking for those groove marks. If no end float, then checking the rod bushings and side play of the rods themselves on the crank. I don't remember the tolerances from memory, its all listed in a decent manual like Bently or Haynes.

One thing to be aware is that those old 40hp cams didn't run in bearings. Also the heads were 'long stud' (check to see if you have them) and they were far from the best design and a lot of them failed. Read a detailed write up about them here...

http://www.thesamba.com/vw/forum/viewtopic.php?t=103248

Also your want the heads looked over, crack tested, guides, valves checking ect.

[Ojai63dbl]

first off

1) the above post is correct - youll have to spec everything

2) engine looks normal - heads and pistons need cleaning, rings replaced

3) Have heads exhaust valves checked / replaced or complete head rebuilt (top end rebuild) (this was to be done at 50K as regular maintenance

BTW 63 were round boss, bt most of these have had short rocker studs installed

3) not much more work to open case, clean, inspect put in new bearings, case savers and be good for another 50+ K. Cam bearings can be cut but might not be needed.

4) good news is the 40hp usually didn't dvelop cracks

[remerus]

No you are right the heads have been converted to short studs so that is not a concern.

Is it absolutely necessary to have case savers installed or is this only if the case studs turn under torque?

[williamM]

It's a precaution fairly cheap and much like rocker studs replaced- the failure is a heartbreaker. As you end up with instant head seal leaks and the repair is another tear down. There are over sized head studs, but real PITA and you are still looking at the other 15 headstuds waiting to do the same.
_________________
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[glutamodo]

I've never known an upper head stud to fail. The lowers are the ones that fail, they have the constant extra pressure of the valvetrain against them. Years ago, I had several pull out on me on a recently rebuilt 40HP engine and after replacing a couple with those self-tapping fix-it studs, I went and just did all of them. They worked, and held until that engine died. It would have been better if I had done case savers during the rebuild though. (however I don't know if I could have found anyone local that would have done it)

[Ojai63dbl]

BTW: Glutamono is The King when it comes to a 40hp IMHO

the answer to case savers is ......well depends (sort of like long rocker studs)

if they feel solid they may be OK, but if you button it up and it comes loose in 500 miles youll kick yourself. I ran lng rocker studs , no case savers on my 63 until I rebuilt engine last year (didn't need to but it is like insurance)

For you

I think the question is how many miles were on engine - were studs loose or at torque when you pulled heads- how many miles do you put on car a year.

How much do you want to spend or do you want to drive it. Machine shop takes time, as do reassemble. A top end rebuild is a weekend job.

TO put your mind at ease:

In the 70's they'd have one a top end rebuild and not messed with studs. In 80's and 90's Id do exactly that - rebuild top until it was time to tear down. Now I tend to do full on rebuild before.

So FWIW:

If miles are fairy low on engine and you are a hobby driver with AAA or an understanding spouse - you could survive a pulled stud and tear it down at that point after a tow home.

With regards to opening case or leaving it alone - sort of same question - low miles with no oil sludge in case and youll probably be fine

But.......Now my view on my 63 daily driver is I rebuilt it completely because I had endplay issues and while I was at it I did cam bearings, case savers, and line bore - it has been a happy engine now for last 20,000 miles. Since I drive it long miles with a wife who has said if it breaks down figure out how to get home I decided it was smart to do a full rebuild.

[williamM]

It is also like cam plug studs- you don't find out their gonners till the case is together and you have sealer hardening by the second.- so stack some sockets and torque test those too.
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[remerus]

Oh decisions decisions to split the case or not... I do however agree while I have it down out and in pieces it would make sense to do the whole thing but my concern is how much it is going to cost me to re do the main bearings, rods, heads pistons etc when initially I only really factored the cost of the tear down and renewing of the gasket kit.

Secondly how long it will take to have heads redone cases crack tested etc etc
then do I do things like having distributors, generators and the like rebuilt to go with the newly rebuilt motor, How far do I go?

[Ojai63dbl]

and before you know it your restoring the vehicle. (LOL)....

Let's review:

your engine, pistons and heads look pretty typical for an engine with at least 50K on it. THe carbon on pistons and oil varnish can be cleaned up. The little bit of oil in cylinder is rings. The carbon in heads is from oil seepage or running rich. (piston rings or tune up). You do need to clean it up to see were you are - and spec the ring grooves. Maybe rehone piston and cyliners



1) Rebuild heads: heads should be a fast turnaround from a shop this will be worth it (1-2 weeks about $200 (might be a high end guess)

2) need to rering pistons ($20) if you don't replace pistons/ cylinder and rehone piston and cyldiners

3) replace pistons and its $200 (AA brand) -

4) engine seal kit ($25)

5) if you have time and tools - new oil pump ($50) or blue print pup an visual inspect perhaps (you need to pull the pulley which can be a hassle there is a tool - but the tool can bend the pulley (did mine) - so a torch and a blunt chisel helps with the puller to be sure pulley isn't dmaged) and pull oil pump which also needs special tools but this works well)

6) can of black spray paint to make everything look fresh

weekend of work nd engine is in by Monday to drive to work

Now if you go to bearings and case- BEWARE THE CREEP!javascript:emoticon('')

my wife claims we need a "if you give a Moose muffin" book for VW owners/garage mechanics.

perhaps "If a VW owner pulls an engine he'll want a special tool to do it with"

or "If VW owner is cleaning engine, he'll want to replace that leaky seal"

back to comments


1) check endplay (if in spec - case is probably fine) but visual inspection after power washing or scrubbing down. I haven't seen a cracked 40hp case but I a easy on them. I am sure someone has.

2) if you crack case, you could just do bearings (need to know size) and stop

But then the creep begins: cam, cam bearings (youll need a 1600 cam plug aftr you have bearings put itno 40hp case), full flow, case savers (8 or 10 mm studs - have to decide) , line bore, new flywheel seal, flywheel remanufacture, rebuild rods, rod bearings, balanced, on, and on (maybe $1500-2500 total - a guess cant remember what machining/ parts ran mel)......
then distributor, carb, genie, starter, fix that rust, bumpers could use a replate. (and the creep begins.....

hmm probably should do new trans mounts, brake, rebuild king link......

been there it just sucks you in.

If this is a fairly well running engine which you have owned for a while. You most likely be fine at top end rebuild and be out to shows this fall.

plus side it is a reliable daily driver - down side the job is now 2 months

[vdubmyk]

I had the same issue when I did my engine. It sat on a stand for two years because of my indecisiveness. I finally decided to not split the case. The engine is the original to the car and I ended up having the heads redone with new exhaust valves, sandblasted the pistons and cleaned and honed the cylinders, new piston rings and a complete reseal of the external gaskets/seals. The rear main seal was the original one. I'm happy to say, I have ZERO leaks and it drives and sounds great. I was worried about the case not having cam bearings and the condition of the main bearings but since it's not my daily driver, I decided it would suffice.

_________________
64 stock bug, 12V (converted 6v unit), 40 hp, all documents even sales contract and dealer window sticker!

[remerus]

[Ojai63dbl]

good decision javascript:emoticon('')


where in Australia? Lived in Townsville in North Queensland for 3 yrs way back when - need to get back sometime to see friends - but too far to swim (LOL)

[John S.]

I pulled the stock 1200cc out of my '63 ragtop this past February.
Nearly identical situation as you have.
Take your time; clean, clean, clean. Then inspect and see what you have.
Allow twice the time you think it might take (money too).

I enjoyed the whole process, had a local guy with a torquemiester graciously come and save my butt when pulling the flywheel. I took the extra time to sand, reprime and repaint everything (including the engine tin) while I waited on a Rimco head rebuild and other parts.

End result was very pleasing. Looks stellar and runs really well.

Just be very patient and allow some extra time and cash.

[jzjames]

[remerus]

Hi Gents,

Just thought I would give you an update on my progress so far..

I had the heads jugs and pistons sent to the machine shop for assessment. It turns out the pistons and cylinders are no good apparently a bit out of spec and was advised by the mech that it was my call but suggested a new set would be wise.

The heads turned out to be good so were cleaned up and fitted with a new set of valves (both inlet and exhaust ) cost me $425 plus parts to get that done.

The next step is to get myself some new pistons and jugs.. So far the only thing brand available to me are AA's which will set me back about $350. Are there any German manufactured Piston/cylinder sets currently produced getting about these days?

Ah yes .. the temptation to crack the case is still looming...

[John S.]

You are following the exact path, pretty much, that I did.
I checked out the pistons and rings and cylinders and they were fine, however.
Used a combination of the official factory manual and the Muir book for
guidance.
Not to jinx myself but I just went over the first 1,000 miles on the rebuild and
she's running great. Still original German internals with a head rebuild.
It's cool to have the original parts still working back there after fifty one years.

Still a billion projects on the car (an excellent thing to look forward to).

Mine looked like this (back in the car!) after close to two months.
I have an correct original distributor to rebuild and add but it runs fine with the 009 for now.

Again, have faith and allow some time and extra cash.

Enjoy

[Chuey]

I have the 1385 kit in mine (AA) and it's stellar. I'd do that again. Also, we installed 1.1to one, newer lifters....the original are 1 to 1. Not a real hot rod but I like the 1385. It's a peppy engine! I'd love to have some of those square boss heads and dual carbs!

Chuey

[williamM]

So far have used AA pistons on 4 and their quality is stellar for both piston weight and ring gap- No problems.

Those heads look great- must be the first cut - valves are looking good, not sunk in on some over cut seats. Lap those cylinders and it should run forever.

Side note- where are you at. Many sambas have been to The Auzzi - I was there on and off for 4 years- should have never left.
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!