Chrysler Plymouth Flathead 6 Broken Tappets

[MickO]

I have discovered that i have 3 broken tappets (cam followers) in my 2.7 flathead 6. They are broken at the head with the edge broken off, i tappet has part of the head cracked but hasnt broken off as yet. I was stripping the engine trying to discover a persistent noise. The engine had a rebuild in the last 10 years with little or no mileage since then. I have recently acquired the car. The car was running and starting very easily. I tested the compression and 4 were 100psi and 2 were 105 psi, which i believe is pretty good for these engines. 6 valves were replaced during the last rebuild. A new timing chain was fitted but i am not sure about the sprockets. on removing the head all looked well with very clean smooth bores. the tappets clearances were pretty good with only 1 a bit too loose. 

Is broken tappets a common problem with these engines ? Should i replace all the tappets or just those which are broken or are showing signs of damage. Can you replace the tappets without taking the engine out ?. I have the car on a lift at present and am getting ready to drop the oil pan.

Any advice greatly appreciated re the tappets and what to do if i need to take out the engine, things to look out for etc

Mick

 

 

[Rusty_OToole]

Never heard of this before. Is it possible the rebuild was done with aftermarket tappets of incorrect material? The tappets can be replaced after you remove the camshaft. The valves must be removed first. Under the circumstances I would replace all of them. I have no idea what kind of car has a "2.7" engine. That works out to 165 cu in, I never heard of one that small. I know they made some special small bore export engines for England.

[MickO]

Thanks Rusty, yes they made a 2.7 for export to the UK between 1932 and 1939 i believe. It has a 73mm bore. Mine is a 1934 Chrysler Kew, same as the Plymouth PE De Luxe. I aquired the car last year and imported it to Ireland. Would incorrect valve clearances cause this ?, I have parts ordered from Andy Bernbaum and will have to add a full set to the order. Can i do this without pulling the engine out, by just dropping the pan and working from below as well or would it be a simpler job if i pulled the engine out. I dont know what went on in the rebuild but some work appears to have been done well and i have receipts for valves, timing chain, con rod bearings, timing chain, water pump kit, chain case cover, piston rings, head studs etc. I dont know if the tappets were replaced or not. Is it possible to prop the valves open to give enough room to pull out the camshaft without removing them and drop the tappets after taking the cam out. I am new to these oldies so it's an exciting learning curve. i appreciate your advice.

Thank you.

[viv w]

I had a tappet head break off on my 28 Chrysler 52 4 cyl. They were factory originals, made with a cast head pressed into a hollow steel sleeve. On stripping the motor we found a bit of sideways slop on all the tappets. We ended up reaming the block slightly and made new tappets out of solid stock.

 

 

 

[MickO]

I have some photos of the broken tappets, No 2 & 3 inlet have their heads partially sheared, and no 4 inlet shows a crack which would have sheared off at some stage. The rest of the tappets appear ok but i am going to replace all as Rusty suggested above. Any advice on the best way to do this is appreciated. I may also have to repair the camshaft or would it be possible to regrind ?. ihave other photos but these show the damage. 

 

 

Edited May 24, 2019 by MickO (see edit history)

[Rusty_OToole]

It should be possible to replace the cam and tappets without removing the engine from the car. You will have to remove the radiator for clearance, then take the front of the engine apart and withdraw the camshaft. You will need to take the head off and  remove the valves. Then it is possible to lift up the tappets to clear the camshaft, and hold them up with some kind of clamp. Then you can take out the camshaft. After that the tappets will drop out. The oil pan will need to be off for this.

 

It may be possible to prop the valves open with wooden wedges rather than remove them. Once the camshaft is out you can inspect for wear or damage. It might be a good idea to have it reground on general principles.

Edited May 2, 2019 by Rusty_OToole (see edit history)

[MickO]

Thank you for your reply. I have everything off now including the head, front grille, radiator and oil pan. will the oil pump have to come out as it is driven by the cam ?. any advice on taking out and reseating the camshaft bearings,is it difficuly to drift them back in ?. From inspection it appears that some of the cam lobes have an edge on them from the broken tappet heads, so i will get it reground. I remember reading an article on Ford flatheads where it was possible to wedge the valves open with timber wedges to get enough clearance to take out the cam and drop the tappets. 

[Rusty_OToole]

You have me there. I have not worked on that model of engine and have been speaking theoretically. You should not have to touch the cam bearings unless they are worn. In case you need new bearings there is a special tool used to press them into the block. An old time auto machine shop should have the tool. Be careful as you take the camshaft out and you will not damage the bearings, keeping in mind that the cams can gouge the bearing if you are not careful.

[ply33]

9 hours ago, MickO said:

. . . will the oil pump have to come out as it is driven by the cam ? . . .

 

Yes.

[MickO]

Well Rusty & Viv, i managed to get the tappets out by making wedges out of PVC Facia board cut with a slot to slide them in past valve stems and prop them open against the force of the springs. I only propped them open about 10mm. I then held the tappets up with solid core electrical cable wound around the adjuster bolt and wrapped tightly around the head bolts to prop them up, this alowed me to carefully pop the cam out with enough clearance so as not to scrape the cam lobes off the tappets. I had Andy Bernbaum send me a new set of tappets and a local Engine shop specialist PJ Donnellan in Lanesborough did a gre at job regrinding the cam as well as skimming the head as it was slightly bowed. The new tappets had the new adjuster which does not have a lock nut on them, they seem to be an interference fit with a fairly tight thread. I managed to eventually wind them down to get the required clearance but had to pop the valves up a little bit more using copper coins in addition to the PVC wedges to get more clearance when getting the cam back in.  I am now ready to get the timing gear back on and the head etc. I am having great difficulty getting a head gasket for the 2.7 litre 19.8hp engine which has a bore of 2 7/8" or 73mm. I believe this size engine was used in the Chrysler crown marine engine. I have ordered 2 seperate head gaskets from suppliers on both East & West coasts but both were wrong and for the larger 3.3 or 79mm bore 23.4hp. Anyone know where i might get one of these gaskets for the 2.7 19.8hp. I attach a photo for comparison.

 

 

Edited May 24, 2019 by MickO (see edit history)

[keiser31]

Have you tried Olson's Gaskets?

https://www.olsonsgaskets.com/

[MickO]

Yep tried them but no luck as yet.

[MickO]

Olson's saved the day. They initially sent me the wrong gasket but when i emailed them they immediately realised their mistake and sent out the correct one for the 2.7 without hesitation and super fast delivery method. Great no quibble service from them.

[c49er]

They are a great company in my backyard (Seattle) so to speak!

I use them a lot.

Edited June 15, 2019 by c49er (see edit history)