Jump to content
Ultimate Subaru Message Board

Recommended Posts

Does anyone have the "valve head" measurement differences between the early 1.8 OHV engine and the 1984-1988 OHV engine, or is there a site that I can go to to get that information?

Share this post


Link to post
Share on other sites

me thinks the data is the same, but not certain if the question is using the actual info or not.

 

OHV engines were the EA61 (1400cc?), EA71(1600cc?), and EA81 (1800cc) aka 1781actual cc's = 1.8L OHV engine

 

the EA82 is the OHC (IIRC) = 1.8L which is also a 1781cc engine

 

so to ask if the 1.8L OHV and the 1984-88 OHV are different I'd believe they are one and the same. How ever as I'm not sure how *old* you rrefering to then I guess we will wait and see if the Old School folks like the Hatch Patrolers and Subaru3 down here in Texas will chim in with the correct info as I'm sadly lacking in that datamine.

Share this post


Link to post
Share on other sites

According to one of the Subaru engine into light aircraft fellows there is a difference in the early EA81 vice the late EA81 valve size. Since I an interested in "reworking and EA81" for max output without a turbo or fuel injection I am looking for the most breathing that I can get. I am going to run this in a 1983 4wd wagon. I would be interested in any input on the EA81T that anyone hasm as well.

Share this post


Link to post
Share on other sites

hydro heads, the ones that say do not adjust are bigger thats the NA version i don't know turbo but i believe that they are the same as the bigger 84+ heads

Share this post


Link to post
Share on other sites

Yeah - the "big valve" heads are the heads for the hydraulic lifter version of the EA81. These came in 83 1/2 and 84 Automatics, and ALL 85 to 89 EA81's. And yes - as for making any major engine mods - you'll want the hydro lifters, as they require no adjustment - adjustment is a pain on a stock engine - certifiable nightmare on a modded one with different cam etc.....

 

The EA81T is basically the same as the EA82T - just different valve train - using the EA81 as the core motor. It has a lower compression (7.7:1 instead of 8.7:1), and it originally came with an oil cooled and oil lubricated turbo. There was a recall to upgrade them to water cooled / oil lubricated turbo's.... they are comparitively rare (only built in 83 and 84), so parts (especially heads) are pretty hard to find now.... they make 95 HP stock compared to the 73 HP of the normal EA81.

 

My personal preference is for the regular EA81 - they can be turned into quite a beast with a cam grind, head deck, and EA71 pistons (yeilding something around 9.5:1 compression), and a weber with a free flowing exhaust - looking at around 125 HP, or more with not much work at all really. The EA81T can run higher boost, and an intercooler for more HP, although there's not been enough of these modded to know much about what they can do. One thing to say - they are not much good off-road because it's hard to keep the turbo spooled. No torque on the low end.....

 

GD

Share this post


Link to post
Share on other sites

Since we are in hot pursuit of "large valve heads and hydralic lifters does any one know the starting serial number range for these engines? I have a couple of extra engines laying around that came out of a salvage yard but I have now idea what year they are in as much as they were sitting in the back room of the salvage yard. They both have EA81 stamped on the heads. One is the standard 2 barrel Hitachi style intake manifold but the other is the "One Barrel" intake manifold with a one barrel carburetor on it.

Share this post


Link to post
Share on other sites

Don't know about serials #'s.....

 

You can tell the hydro lifter engines - they have a gold sticker on the valve cover that says "do not adjust valve lash" or something like that. If you see remnants of a sticker.... that's probably the one.

 

Other than that - I don't know about carbs - the carbs were specific to the type of vehicle - generally the single barrel carter / weber (peice of crap BTW) came on 2WD's - but not all 2WD's. Some Auto's too I think. Mostly on the 2WD 5 speeds I think.... not all of those either tho - mine had a hitachi....

 

GD

Share this post


Link to post
Share on other sites

Thank you for the information on the valve cover decal. I am now better equiped to go in search of these engines. I always like to have one or two spares around. My last big project was to completly rebuild an International SV392. These weigh about 800 lbs complete so I don't keep one or two extras of those laying around. They are too damned heavy to move by myselt.haha

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×