8ba valve train help needed
 

This should be easy but...
I am putting together an 8ba with a merc crank, nothing special. The last motor I did a number of years ago I got all the stuff from H&H because I figure if they build, then they sell me what they warranty. Figure I got some tech support as well.
Anyway I asked for a 77b cam and they send me this 3/4 grind they do with 274 degrees duration. I sent that back but it took too much time to get a call answered, then Mike tells me he cannot get shit form Isky now. Whatever.
Anyway he sends me the chevy valves with Isky springs that appear to need to be installed at 2 inches to achieve 80 lbs seat pressure. After cutting the valve seats I figure I need a lot of shims and start to do some research. The consensus here is 50lbs is sufficient. These springs will obviously not work at that pressure. I'm not too thrilled about the longer valves either but Mike said it is all he sells.
Now that I have laid out my mistakes, what do I need to do to get on the right track? Obviously I need to buy different springs. Will the chevy valves be a problem or should I just get stock ones to save me the headache?

I'm not really in too much of a rush just trying to do things best I can. Last motor I built I just installed these springs because that is what was recommended. It has not failed me yet but still thinking it could be better.
I guess you can get bad info talking to an experienced builder.

Thanks for any help.

Re: 8ba valve train help needed
 

Don't you have to open up the valve seats in the block for chevy valves? So going back to ford valves would take new seats.

Re: 8ba valve train help needed
 

Get a set of stock valves from 3rd Gen. What are you looking for in a cam? I generally use Lincoln Zephyr springs.

Re: 8ba valve train help needed
 

Whatever you get for a cam, 274 is too much for a mild street engine.
Isky 185 or zephyr springs are plenty adaquate. 60 lb. on the seat is plenty for a mild cam.
Stock valves will work ok.
You don't need any fancy machine work, just face the valves and seats and put it together.

Re: 8ba valve train help needed
 

If your seats are still sized for stock, then just buy aftermarket stainless Ford sized valves and run stock springs and forget about all that other hassle. If you really, really fussing around with things, you can do such fun tricks as:

offset locks
extra thick, custom machined retainers
mix/match thin shims with above to try and eliminate the shims altogther

All of which is what it took me to make the 1.60" ProFlo small block chevy valves work. I found it too be very overkill on something that won't ever see probably 3500 RPM. So my next engine went stock with valves from Mike as the post immediately above suggested...so much easier!

Re: 8ba valve train help needed
 

5 years ago I built an engine. I bought most of my parts from Reds Headers. I used Chevy SS undercut valves because I was using a small base cam and was told the extra length was needed to prevent the adjustable lifters from being run out too far. I bought Zephyr springs and used one .060" shim on each and an additional .010" on a couple to get ~50# on the seat. I did have new valve seats, though.

Re: 8ba valve train help needed
 

I’m not an expert by any means,,,,,but I plan on using the Chevy valves because of the reduced base circle on my reground cam .
My engine will not be a race engine,,,,,but I planned on an increase in both HP and torque .
And I like to have a fair amount of RPM a5 my disposal,,,,,,just for when you feel like letting the badger loose now and again .
Also,,,,,I plan on it going into a performance hot rod,,,,,so I want the old flatheads to have some respect from people that have never even seen one,,,,,LoL .

Tommy

Re: 8ba valve train help needed
 

Frank,
The chevy valves will work fine. You will need to grind them a lot. I installed a set two days ago. I don't Use adjustable lifters so in many instances recently using reground cams I have to use Chevy Valves for the longer stem length. if you are using adjustable lifters this wont be a issue, but I prefer stock lifters and grind the valves to suite.... Lighter and they wont lose adjustment

Re: 8ba valve train help needed
 

Why do you thing the 185g springs wont work? Have you assembled your valves with a mock up spring to measure the installed height? Shoot for 50-60 lbs on the seat for good heat transfer and positive seal at moderate rpms. Check you spring pressure is at installed height and adjust accordingly. You can get offset keepers to eliminate too many shims if needed

Re: 8ba valve train help needed
 

Having installed a dozen or so L-100 cams I've always used srock Chevy valves which have the same size heads as the flathead and longer stems. the longet stems make up the differance in the small base circle of the reground cam and keep the lifters from loosing up. as for springs I just used the stock ones with a .060" shim which usually brought the pressure over 50lbs at installed height, which most people don't know how to measure. I gave Frank all this information.
Gramps.

Re: 8ba valve train help needed
 

Thanks Ron.
The 185 g will work just not at the lower rate because the springs will be too long and the rate does not ramp up until it is much shorter. I could set the 185g where they suggest but it is excessive and use power and creates heat. Just trying to do it the best way while I'm here.
Thanks everyone for weighing in. Too much to know for a glorified lawn mower engine.

Re: 8ba valve train help needed
 

Measuring the installed height is the key to this thread.