so i had a head gasket blow yesterday and im wondering if anyone has any tips regarding replacing them. ive done head gaskets before but on a inline 4 DOHC engine. but due to this being a pushrod engine, i want to know if theres any specific things i need to know to not cause any excess damage

If you have already done a overhead cam engine you did the harder motor IMO.  I would get yourself a "how to keep your subaru alive" manual.  They are very detailed and actually pretty fun to read.  Now are you pulling the motor to do this or doing it in the car?  Its really not that much more work to yank the motor in one of these cars and you will be able to do the job easier with the motor out (though it can be done in the car).  Basically instead of dealing with the timing belt you are dealing with pushrods.  No big deal really.  Either way you do it you will need to pull the rocker assembly's off and pull the pushrods out before you can yank the heads off the studs.  You may need to tap on the heads with a rubber mallet a bit to break the seal.  

Edited October 2, 201510 yr by hatchsub

the engine will be in the car for the repair unfortunately. its in a parking lot and i dont have access to a garage at the moment. are the pushrods held in by any bolts or something like that or are they just kind of floating between the lifters and rocker arms?

Floating like you said.

cool. any parts i should specifically inspect for damage while i have the engine apart?

You can look at the cylinder bores.  Look at all the rockers. 

 

Best way to avoid snapping a stuck bolt - get the engine to operating temperature, then carefully loosen the bolts.  Intake manifold bolts in particular.  Head bolts - Not sure when they switched from studs with nuts to bolts.

 

You need to resurface the heads.  There's a thread on here on how to DIY, or go to a machine shop.

 

When you put the rockers back on, check that they are all in place correctly, a couple times as you bring the nuts tight.  Best if you can turn the engine until they are all released [all valves closed] on the side you are doing.

 

The intake manifold gasket mating surfaces might need resurfacing also.

Make sure none of the pushrods are bent.... I would keep them in the order that you take them out (like tape them to a piece of cardboard labeled front to back)

Make sure none of the pushrods are bent.... I would keep them in the order that you take them out (like tape them to a piece of cardboard labeled front to back)

Yup forgot to mention that.  Head studs will remain on the block and will need to get cleaned up a bit while the heads are off.  It can be done in the car its just going to be a bit harder but still not too bad.  

so after reassembling the engine, when i got to start, the crank spins, but it seems to have no resistance from compressing cylinders and there is no fuel ignition. im very confused now. also how important is pushrod order? from whst i found online there is only 1 pushrod to buy so i would think order wouldnt matter

Edited October 4, 201510 yr by zmarrott

where is the best place to buy pushrods from? 2 of mine got bent when i tried to start the car

someone will have them but you may need to measure up a good one, to add those details here or make a want ad .There are two types, at least, note the knurled grip markings and the ends.

 

Did you set valve adjustments at rockers and turn engine over by hand before trying to start by cranking over? If the valve clearance too tight , valve not close and you will get a low comp like effect.

 

Did you do one side or both ? Replace head gasket I mean ?

 

The next  two push rods might get bent if no work out the cause

getting them off rockauto. both gaskets were replaced. the rods that bent were from opposite sides of the engine too. one passenger rear rod amd the other drivers front rod. im pretty sure they bent cause i didnt set them to the lifters properly. i also didnt try to adjust any valves. i figured with no compression issues before hand, i wouldnt have to. what i get for assuming. anyone have a good guide for valve adjusting i can use? i did have a valve tap-ish noise prior to the head gasket blowing

Firstly is it a solid lifter engine or a hydraulic lifter model, I suugest you check the stickies at the top of the old gen discussion to make sure which one you may have.

 

May being the operative word as people can and do mix and match componets sometines when overhauling an engine you likely do not know the history of.

 

I suggest you trial fit the pushrods bewfore you fit the rocker gear to make sure the cam is in the right position with all valves closed or on the rock between one opening and one closing to make sure they do not get bent again, Check, Check and check again and tighten the rocker gear slowly and evenly after making sure the pushrods are correctly located top and bottom.

i have no idea which lifters i have, and the engine is not the original in the car, so i dont know when it was made. would my old pushrods be able to offer up which type of lifters i have? engine is in the car, so i cant get a good enough look at the lifters themselves

I may be able to add something for someone to exp[and on. I know two types of push rod.

 

All alloy tubing, with steel end caps both ends, yet one end has knurling on it, to go at rocker end.

 

Then also have some all steel ones with just ends shaped to round _ these may be the hydraulic lifter ones as I think I only have one set and had one hydraulic lifted/imported engine. Once read that the oil delivery differed to rocker ends if you mixed types up. The holes in each end are the same size though..

 

I bent both back rods, found valve stems were stuck/gunked up with wet sticky shiny black gunk that smelt same as the 8 year old fuel. I ran it on old oil, old fuel had been drained but must have left a residue to be disolved by fresh fuel, car sat, next start was hard, and took a fresh battery on crank to bend the rods.

so my pushrods are smooth the full length, which if your right, jono, means its hydrolic lifters. the picture from rockauto appeared to be the same, which they should be here sometime tomorrow. this is a picture of one of my bent ones. id clean the carbon off if i had the time and money to properly rebuild the engine, which i will do sometime in the future, but cant at the moment

i got the car running after getting the new pushrods and pretty much quadruple checking they were all in properly before trying to turn the engine. made sure i could hand turn it fully then oil change and new coolant. took about 10 minutes to cook out all the coolant that was sitting in the exhaust. gotta do a valve adjustment though. has some trouble staying running.