The Stovebolt Site Forums The Shop Area Engine Shop 194 head on a 250???

Got a call from the shop that was supposed to clean up my head and relap it. First off, he said he ran the casting numbers, and the head is for a 194 CID. Next, he told me the valve seats were worn and it was basically shot. So, i'm paying $375 for a new head that's fit for unleaded gas (he said my old head was more likely all torn up cause it wasn't made for unleaded?), but this includes shipping and i was told it's a good deal? Any way, just wanted to see if yall could tell me how the hell a 194 head fits (and RUNS) on a 250 block and if i'm making a good choice to buy another 194 head, or is it imperative to get a 250 head. Thanks in advance.

The 194 head will work fine on the 250 engine. THey are often used because it gives a little higher comp. ratio. The valves & ports are the same size.

the 194 head is desirable due to the smaller combustion chamber. The valves and ports are the same size. Consider it a poor-mans high compression re-build. I would use the 194 and put in hardened seats.

just my two cents

Scott

I too would rebuild the 194 head. It will boost the compression from 8.0 to 1 up to about 9.0 to 1. This is the best performance boost you can do for no extra money. If you don't use the 194 head, post in the swapmeet area, I know a guy that might want it! Joe

you are running the stock valve train right? the 194 head can run into clearence issues with a high lift cam, i think. usually hardened exaust seats and guide check will do at a minumum, but as always- lots of differences of opinions here. make sure they don't just knurl the valve guides but install new ones if needed would be my only sugestion. hr

If my memory is working, the intake valve is 1.74" and the exhaust is 1.5" for the 194, 230, 250, and 292. I have a 194 head in the shop right now for rebuilding. The shop owner says do NOT put hardened seats in the head, period. This guy builds Chevy stuff almost exclusively, and does a lot of older heads. He told me that in his experience over the last 15 years with unleaded gas that guides give more problems by far than seats. He also advised me to go 3 angles on all the seats but leave the valves alone at 45. I have been doing business with this guy for over 35 years and he has never steered me wrong. I know that this flies in the face of what we read, but this is real world experience speaking, and I trust him enough to let him do my head.

best wishes,

Les

I should have mentioned the guides and seats as Les has. I am a strong believer in not replacing the seats unless its the only way to save the head. New guides are a must, knurlling is for something you are selling right away!

You will never run this thing long enough or hard enough to burn a seat with unleaded gas. Joe

Well i sure do appreciate all the help guys, the head should be in tomorrow and we'll see how he runs. (That's right, my trucks not a woman!)

well if you truck isn't a woman, that changes everything. hahaha just kidding. i have heard that the guides are the problem before aswell. i have also heard just the exaust seats are the ones that have problems. i don't know for sure, that's why i stuck in "there are many opinions on this" in my first post. well a lot of things that work that others will disagree with so i always like to get lots of opinions and go with what i hear the most. that's why i usually have exaust seats done and all valve guides. i was also told that a 3 angle valve job will seal better but does a poorer job in heat transfer from the valve. so i don't know about a 3 angle on a stock head, i personally wouldn't. and would it justify the cost? we all know what a comp valve job costs. if it does do a poorer job of heat transfer will the valve last as long? i have heard a lot of crazey stuff from "oldtimers" while most is sound i wouldn't put money down on all of it. i bet we could find a head somewhere that someone has ran unleaded in at 4500 rpm's for weeks on end and it is running fine, but should we all try it? i am sure not saying anyone is wrong, but you will definately hear conflicting opinions.

hoggyrubber,

Three angles are cut on valve seats to adjust the height of the valve on the seat and to optimize the seat width for best seating.

There are specs for valve seat width. I was not talking about race work, but a standard 1/16th seat. I doubt that there will be any "heat transfer" issues since 1/16 to 5/64ths is often specified as new stock on many engines. Wide seats have more chance of not aligning properly and burning. I hope this clears up any case of poor writing on my part.

Best wishes,

Les

"Interference angle" seating, 45 degree valves and 46 degree seats, is a quick production method to turn out a lot of heads in a hurry at the factory. On any precision buildup I do, whether for racing or trailer towing, etc. I always do a 3-angle valve job. It's possible to custom-tailor valve seat width to the type of engine operation, narrow for speed and horsepower, wider for heavy load applications. It's worked for me for over 40 years, with no concerns about short valve job life except for maxed-out race engines that aren't expected to last long anyhow!
Jerry

i sure didn't think you did a poor writing job les, i was just passing on stuff i had been told by different machinists. can i vouch for it, no way. i was just sayin you will hear all kinds of conflicting info. let me tell you i have not installed a valve seat or cut a valve seat, except some for fun on something i never ran. so i can't and don't speak from experince here. i am sure not a valve guru. when i was talking to a machinist for a 3 angle job he told me it wouldn't last as long and wouldn't be worth the cost. in their defence we didn't talk specifics about seat width so like hot rod lincoln says i'm sure they can be tailored to work and, prob better, on most applications. but if you just went in and asked for a 3 angle valve job i'm still not sold on it being worth it on a stock head, but i will be the first to admit- i am prob wrong. i got a 3 angle on my last 292 but it has a higher comp pistions and high lift cam. my overall point was you will hear lost of conflicting info on unleaded gas and valves, so you have to decide what you are going to do about that.