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building a hotrod head
https://www.slantsix.org/forum/viewtopic.php?t=24735		 Page 1 of 2
Author:  mopardemon71 [ Fri Aug 31, 2007 8:08 pm ]
Post subject:  building a hotrod head
Long time to type. I've sent off a head to have it worked up. I have been working with a guy thats a machinist at my new job and he's helping me out with it. Its getting 1.72 int. and 1.50 exh. valves that are stainless, a radial valve job, I think its going to have 11/32 valves and guides. He doesn't want to hack anything off the head but what is needed, he wants to build the compression with a custom piston(he "knows people"). So I need some info on the erson cam spec's. If some one would jot down the spec's I cant ever follow the links that people put up.

What is the going spring these days? Is every one still trying to use 340 springs?

I'm thinking of getting one of those ebay 262 comp cams kits but if doug might have some insight on a good stick that would help too.


the short block will come later (thats more pricey) so now i'm on the hunt for some good headers that wont kill my bank account. i'm trying to use a bbd only for the carb. The why I see it if it can feed a 318/360 it will work on my slant.
Author:  greasy 225 [ Fri Aug 31, 2007 9:01 pm ]
Post subject: 
I dont know how big or small ya want a cam but I just bought an Erson 280, matching springs, and lifters for $210 shipped to my door. I thought that was a pretty good deal(the group buy is still goin on as of aweek and a hlf ago). Why the 11/32 valve stem? The engnbldr (e-bay) valves I got look damn nice for 60 bucks and are stock stem dia.(3/8" I belive?), or are you thinkin that the 32nd narrower stems will help the flow that much more? Im really curious cause Im doin up my head right now too.
-Jesse
Author:  slantzilla [ Sat Sep 01, 2007 4:43 am ]
Post subject: 
Installed properly 340 springs are good for .525" lift. The 11/32" stems means he is probably using Chevy or Ford valves, no big deal as long as the stem heights are correct when done. Very good choices on valve sizes too. :D

As for a cam, what carb, compression, trans, converter, gear will you be using, and what vehicle weight? Street/strip, strip only, street only? Performance use or towing? :?

I always like to use as much camshaft as I can, but you will be better off with too small rather than too big in a Slant. Too much cam will make a little motor miserable to live with. :cry:
Author:  slantasaurus [ Sat Sep 01, 2007 6:47 am ]
Post subject: 
Quote:
Installed properly 340 springs are good for .525" lift. The 11/32" stems means he is probably using Chevy or Ford valves, no big deal as long as the stem heights are correct when done. Very good choices on valve sizes too. :D
I'm using Ford 3.8 valves myself. 1.74 & 1.5 , stem length is within a few thousands (longer) of stock slant, springs are 340, shimmed to correct pressure with longer valves. Rocker shaft will also be shimmed to correct geometry.
Author:  Slant6Ram [ Sat Sep 01, 2007 8:47 am ]
Post subject:  Do hack
Quote:
He doesn't want to hack anything off the head but what is needed,
What is the reason for this direction?

There is little reason to protect the head thickness. There is way more material than necessary and it isn't rare to take 0.10 inch off a slant six head without any alignment or weakness concerns. This is a good move to get more CR without any downside.

Based on reading about other builds and taking to more experienced members, the slant six piston (225 engine) is already perched pretty high on the rod. That 10th off the head won't do anything but make future block/ piston prep/selection easier.
Author:  mopardemon71 [ Tue Sep 04, 2007 5:58 am ]
Post subject: 
The 11/32 stem is for a tad bit more flow any thing will help. I told my friend took take off .045 and he started going on and on about"correct alignment and push rod angles" so what ever.

My car will be a street/minor strip car. I'll be running a 2200 to 2400 stall behind a 904 and a 8 3/4" with 3.23 or a little higher gear, but I run on the highway a bit so nothing to low.
Author:  Slant6Ram [ Tue Sep 04, 2007 9:14 am ]
Post subject:  More
Quote:
correct alignment and push rod angles
Not at .045, that will little more than make up for the difference between the stock head gasket and the common (thicker) replacement gasket. You'd have to dig around for the true differences, but the geometry won't be messed up, I can tell you that.

.045 is a very sensible and conservative and mild enhancement to even a stock motor.

Now if you took a 10th off the block and a 10th off the head, then you would be looking at custom push rods, but those are still cheaper and less logistics than trying to make up 2/10ths with a custom piston. (based on my study of the slant six projects of others) This is slant six specific info, I don't know a thing about building up a chevy or even a 318.

Not that I'm trying to pick a fight with your mechanic. Keep your mind open to the experience of others and you may both learn something. Seems silly to let you repeat the mistakes that have been made by others.

Don't take my word for it. Somebody back me up (or shoot me down please) The geometry is not a big deal and this is a good place to pick up a little extra early in the build up game. Even .060 is a mild start for a head.
Quote:
I'll be running a 2200 to 2400 stall behind a 904 and a 8 3/4" with 3.23 or a little higher gear
This stall speed is very close to stock. You shouldn't have to dish out a lot of $$$ or I would say to stay stock if your cam choice allows. A common complaint on such a mild performance stall converter is that no change is noticed at all. I think it is very critical to find a converter shop that has experience with the slant six community so they will get it right the first time. Lou Madison has a working relationship with a company and so does Doug Dutra.(Might be the same place) Either way, I highly suggest you talk to one or both of these guys rather than order through a catalog.

As for rear gear, I really like the 3.23 for a mild strip car and found it a much better choice than 3.73 for the highway. I even liked the 2.94 gears with short back tires and a stock stall converter, but this was with a low first gear truck 904. I didn't like the gap between first and second on that trans and I will be swapping it out for a standard geared 904 this fall and keeping the 3.23 rear while I try out a new motor and a 3500 rpm stall converter. I have concerns about this converter for highway use, but I couldn't resist as I purchased it in a package deal.

I drive my car a couple of times a week in the summer and as far as Columbus (about 3 hours) to drag race. My opinions are based on 3 years of trial and error with 3 cars and perhaps 7 motors as well as reading and talking to racers and members of this forum during that time. I don't plan on trailering my car any year soon and have found that street/strip is a very tight rope to walk, as mine won't get great gas mileage or be the fastest car in it's class, but it's lots of fun and the most practical choice for me.

I wouldn't repeat myself unless I though it was important.
Author:  sandy in BC [ Tue Sep 04, 2007 9:40 am ]
Post subject: 
If you are installing 1.72 intake 1.50 ex chev springs there are some things to note.

The stem length + compression mill will take you into the geometry issues you speak of. With a Comp 264s and chev valves I am at the limit on rocker arm adjustment and had to use jam nuts to keep my valves in adjustment.

To use valves that size you need to "sweep" the chambers around the valves. Otherwise your nice big valves are too shrouded by the edges of the combustion chamber killing flow.
The theory I used was to mill the block leaving a large combustion chamber. To get the same effect you could mill the head and notch the bores.
Author:  mopardemon71 [ Tue Sep 04, 2007 1:04 pm ]
Post subject: 
The radius valve job is going to unshroud the valves. It is the next step up from a "five angle" job. I thank every one for their input and it is much appreciated.

I think that the guy thats doing the head is really on it and he likes his mopars so that helps.

Maybe I'll step up to 3000 stall after your input slant6ram.

And I'll still get that .45 off the head.
Author:  Slantenstein [ Tue Sep 04, 2007 4:15 pm ]
Post subject: 
After reading a thread from Doug Dutra explaining that he got his torque converter for his slant from Continental Torque Converters in Inglewood, Ca. I called them up.
I spoke to Peter at Continental Torque Converters with the specs. of my slant and the type of performance I was looking for. I could'nt be happier with the performance I got from the converter they made for my slant. Call Peter at: 310-674-1072. Hope this helps!!
Bill
Author:  Brian [ Tue Sep 04, 2007 5:50 pm ]
Post subject: 
Quote:
I wouldn't repeat myself unless I though it was important.
:shock:
Author:  slantzilla [ Tue Sep 04, 2007 6:04 pm ]
Post subject: 
Take .100 off the block and head and send Smith Brothers $100 for a set of pushrods. :shock:

www.pushrods.net
Author:  Greg Ondayko [ Tue Sep 04, 2007 7:14 pm ]
Post subject: 
Brian, Nice Sig Picture - Can I take the Duter off my site to free up some space??

G
Author:  mopardemon71 [ Wed Sep 05, 2007 8:50 am ]
Post subject: 
Well boys easy now :lol: I m only having the head done first and then I'll move on to the short block later when the pocket book gives me a green light. There is a article that shows the cr to milling and I liked where the .045 was sitting.

Im not spending to much money on this I'm building a 452 big block for my demon so I'm just having fun with my slant right now.

THanks for the links for parts everyone. I'll up date later today on how much i'll take off the head but fyi I'm only looking for 9.5 to 1 on the cr.
Author:  mopardemon71 [ Fri Sep 07, 2007 1:34 pm ]
Post subject: 
Well I hope this isnt a dead thread but I convinced my friend to start at .050 off the head and we will go from there. He can be stubburn untill he understands things :D .

I'm going to give the Jim Cox a call for some parts, he wants to start the short block so maybe this is where I should start and leave the big block on hold for now. Im not sure if they changed the cam profile at any time in the 225 but does anyone know?
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