Motor swap "es" into "is"

[Keith M]

I think the issue here is that he has a b25 and is talking about swapping a b27 head on it.

[BigBillions]

i figured it out. the only differences in the head is the valves and cam go for rev. swaping those you can get the higher revs its pretty much the same as putting a i head on a seta motor except for not having to actually swap the head off and on. the seta head is a 885 cast just like the i head but with out the double valves springs and littler bit bigger cam they even have the same amount of cam bearings. the e head has more cam bearing and is a different casted head.

[Keith M]

What are you trying to achieve?

[ForcedFirebird]

i figured it out. the only differences in the head is the valves and cam go for rev. swaping those you can get the higher revs its pretty much the same as putting a i head on a seta motor except for not having to actually swap the head off and on. the seta head is a 885 cast just like the i head but with out the double valves springs and littler bit bigger cam they even have the same amount of cam bearings. the e head has more cam bearing and is a different casted head.

seta motor has the 885 head casting like the i, only the cam is different. It's rare for an 885 head to have 4 cam bearing journals.

Are you trying to stroke the motor in your car? All you need to do is put a seta bottom end in it. If you are trying to make an e motor better to put it in the car, use the i head and call it a day.

[BigBillions]

i get that but my 3rd cyclinder is gone in my "is" motor i doubt its the rings its more than likely my head thats messed up this is why i was gona do a valve spring and cam switch in a running es motor. so are you saying the seta head has double valve springs. as far as castings go the "es" and "i" are the same. same journals same amount of cam bearings. maybe different size valves im going to look into it.

[ForcedFirebird]

i get that but my 3 cyclinder is gone in my is motor i doubt its the rings it more than likely my head thats messed up this why i was gona do a valve spring and cam switch in a running es motor

Rings will bleed down slowly unless broken. But be concerned if one cylinder is more than 10% lower than the rest (bad head gasket may/may not cause 2 bad cylinders in a row), a bad valve will make an incredible low cranking compression on that cylinder. Do a compression test and report back.

If you pull the head and take it to your local machine shop, you *might* be in for $200 if it's not cracked for repair. Buy a gasket and put it back together. If you have more time than money, this is your best option at the moment. If m20's are being sold in your area, it's faster just to swap an m20 back in than taking one apart, but area is everything weather or not one is available for less than repairing an engine.

[BigBillions]

i did do a compression test the number 3 cylinder is at 76 psi and the rest are at like 130 psi. i havent found an i motor for sale close to me or for a decent price.

[devon.818]

uhm, i think all your cylinders are low buddy!

142-156 psi is the spec

your motor sounds fucked up

[BigBillions]

motor has 230,000 miles on it

[ForcedFirebird]

uhm, i think all your cylinders are low buddy!

142-156 psi is the spec

your motor sounds fucked up

That's not entirely true. With a tired/high mileage I have seen as low as 135 across the board. It's when you have more than 10* variance there is an issue. Sounds like a burnt or bent valve to me. Pull the head and have a machine shop look it ober. Your m20 will be back running better than ever in no time so long as it's not cracked.