First off, sorry about the length. I have a chance to get a set of these at what I think would be a good deal. They have been slightly ported and blended and flow 265 intake and 179 exhaust. They have guideplates installed also. I can get them for 450 shipped. Does that sound good? He said that they have 62 cc chambers but when I looked at them in summit they show 64.

I was also wondering what kind of power they should make on my motor(power or times).

350

freshened up w/ stock pistons
comp cams xe 268 cam
Hooker long tubes
dual 2.5" mandrel bent exhaust with h pipe and bullets
performer rpm intake
cc quadrajet modified to open to 750 cfm w dr rods/b hanger
dual snorkle air cleaner w/ k&n
stamped rocker arms for now

The car also has a 700R4 w/ a 3000 stall(seems to stall at 2600-2800 on my car) and shift kit, alum drive shaft, 3.45 posi bw rear with potenza re730 tires.

I currently have ported 416 305 heads on it. They have the stock valves in them though. I have a set of 1.94 and 1.5 stainless valves I was planning on putting in, but it would cost me about 200 bucks to have a machine shop put them in. I can probably get 150 for my heads, and that would cut the price down to 300. That would be only 100 more than it would cost me to have the valves put in my heads now. I currently can outrun a stock 89 350 tpi IROC my friend has pretty bad, but it has 2.77 rear gears and we are not sure it is as strong as it should be right now. I have also out ran a 2000 Mustang GT(sort of). I didnt really race that one, but she tried to keep up with me when I got on it from a roll and she couldnt. I dont know how bad I would have beaten it.

What do you think. I figure if I dont get the heads I will be getting a new hood, but I can get it later. I may not be able to find a deal like this on decent heads later. So does it sound like a good deal?

Thanks

Ben

 

sportsman II's make exceptional power, however, with the bigger combustion chamber, you will lose compression. i personally say go for it, but some of these guys on the boards may disagree. i have a set of 416's that i am going to port and polish and stuff for my 305, the 383 however will have something much bigger...

 

Sounds like a good deal. If you're using composition head gaskets now, using steel shim gaskets on the Sportsmans will help regain the slight compression drop. The improved flow and chamber shape will overcome the compression drop even if a composition gasket is used on them.

Might want to consider a little more work on the exhausts. They're only flowing 67% of intake. The cam will help a little, but at least 70% (185 cfm) would be better.

 

If I do a little work on the exhaust and get them up to around where they should be what do you think it will do power wise? I am currently using a composition gasket, so I can switch to the steel shim style. I emailed him to make sure that they are either 64 cc chambers or that he had them milled to 62 or something because 72 which is the other option for them would be to little compression if he made a typo.

Thanks

Ben

 

You can expect 410 to 425 hp out of those heads bolted onto your motor as you listed it. Probabily about 60 hp more than you have now.
If they flow as claimed, they are capable of makeing more power
with different parts. about 500 hp potential at that flow.

The 416's have more potential with the larger valves and more porting but the Sportsmans you discribed look like a good deal.
You could sell off the 416's and the extra set of valves and
be all set. Go for it.

They are good heads (when ported a bit as you discribed)

. and will respond to more camshaft for even more power.

 

Would I be able to use narrow bodied roller rockers or would I need to use the normal ones? Are there brands I should look for or stay away from? Will I need a different length pushrod(I know I need hardened for use with the guideplates)?

The heads are 64 cc. How much do steel shim head gaskets raise the compression?

 

Stay away from aluminum roller rockers, if you want long-term reliabilty. I'd strongly recommend the Comp or Crower steel ones.

Same for the steel shim gaskets. If you're working the short block over anyway, just use flat-top pistons and have the block decked to the low end of the stock deck height spec.

RB's rule of head gaskets: a motor with head gaskets that seal is faster than one with .1 points more compression and leaky head gaskets.

Get an adjustable push rod, and after your motor is all put together, use it to measure for optimum push rod geometry.
http://www.compcams.com/catalog/278.html
http://www.compcams.com/catalog/279.html

 

I already have an adjustable push rod. The motor is together now and being driven and wouldnt be coming out so I wont be doing any work to the short block so I cant raise compression that way. I will just be doing the head swap. I am using standard length pushrods with the stamped rockers and 416 heads. I guess I will wait to get pushrods till I check what length they need to be for sure though.

Does anyone know about what my compression would actually be? I have a stock 010 short block. I think it is from about 78 with 4 valve relief pistons. Everything is stock other than having new bearings and rings and such. The heads are 64cc. Also, are the steel shim gaskets that hard to get to seal? Would having the heads milled be an option? What does that usually cost?

Thanks for the help.

Ben

 

If it's a stock 78 motor, then it has dished pistons like they all did, and your CR with 64cc heads will end up in the high 8s to low 9s. If it has pistons with 4 valve reliefs, then they're probably flat-tops and not stock ones, and the CR will be about a full point higher.

Yes, it is hard to get steel shim gaskets to seal, especially with old surfaces on either the block or the head side of them. Every single one I have ever taken out of a motor, even out of motors that didn't obviously run like a failed gasket, had signs of combustion leakage. That's every single one; not alot of them, not most of them, not almost all of them, but every single one. That includes stock motors that came with them, replacement ones, rebuilds, you name it; if you tear a motor down that has steel shim gaskets, you will see combustion leakage every time, especially between the center 2 cylinders on each side. I will not build a motor with them no matter what the CR difference is.

When I said steel rockers, I wasn't referring to stamped rubber ones; but rather the cast steel ones such as the Comp 1300 series.

 

Why not mill the heads before you put them on to get some compression back?

 

Ok, I wont use steel shim gaskets first off.

Second, I understand what you meant by steel rockers. I was planning on using the comp cams pro magnum rockers. I was just telling you what is on the motor now. It seemed that you were under the impression that the motor wasnt together yet, and I just wanted you to realize that it is and I am driving it now.

I know the guy that redid the motor, so I will ask him about the pistons. They definately did have 4 valve reliefs though. What exactly does a dished piston look like(can it have valve reliefs also?). I am pretty sure they are flat tops though.

Also, as far as milling the heads, I asked about that in my last post. I was just wondering how much that would cost. I also need to find out what my compression will be first before I mill them.

Sorry about the confusion, and thanks for the help. Hopefully I will get all of this figured out soon. lol.

Ben

 

The Comp 1300 series are the Pro Magnums, so that's good.

A dished piston looks just like that, a dish. It sort of looks like it has a shallow bowl in the top of it. Usually they won't have valve reliefs because (a) the dish moves the top of the piston downward and out of the way far enough that they're not needed, and (b) dish pistons are usually used in low-performance, stock-type applications, where big valve lifts aren't an issue anyway, so there's no sense in spending money creating them. So, if your pistons have valve reliefs, chances are, they're flat tops.

Milling heads is cheap. I've had them milled whie I waited - just walked in, said "Hey can you mill these" and handed them to the guy, and walked back out 10 minutes and $25 later. It was somebody I knew, but still. The worst thing about it, to me, is that it's irreversible.

Nobody can predict what your CR will be without more information; most especially, the block's deck height. The builder might be able to tell you that. Usually people do one of 3 things: leave it alone and clean up the surface only as necessary, which is usually insignificant to CR; or they mill them all down to the bottom of the stock spec; or they match them to the pistons. #3 is the high-$$$ way. #2 is the standard race engine shop method to "mass produce" motors, since it's not necessary to match a block to a set of pistons. #1 is standard for a low-buck rebuild, or in racing where the compression can be adjusted otherwise.

THere are lots of compression calculators all over the net, maybe even on this site. IF you measure the approximate area of the combustion chamber, like if it's 3¾" long x 2¼" wide and it's 85% of the area of a square that size, you could calculate how many cubic inches of it you'd remove per thousandth of milling, and use that in the calculator. Aim for 10¼:1 with a Fel-Pro 1014 (.039") and whatever your builder says he did to the block.

 

Well, I thought that those were the stock pistons. I also though that the block wasnt decked, but I dont know for sure. I guess since it appears that he changed the pistons, I better check with him on whether it had been decked. I can still read the numbers stamped on that flat surface at the front of the motor. I thought that you couldnt see that if the motor had been decked. Is that true?

Thanks again.

Ben

 

Generally so, yes; shaving metal off the deck usually takes the numbers with it.

Sometimes you can measure the deck cleaeance, which is how far down in the bore the pistons are at TDC, with a feeler gauge. It might be worthwhile to try that.

 

I am going to try to get ahold of the guy that built it first so I can see if he remembers what all was done to it. I might see about measuring when I take it appart, but currently I am still driving it.

Ben

 

Well, I should be getting the heads. He is going to throw in a set of rockers also. They are proform which I know probably wont last very long but it will give me a little time to save for the others hopefully.

What kind of times do you think I could get with this setup assuming I get the compression to around 10 1/4 like suggested and can get decent traction, or better yet mph?

Ben

 

I'd expect low-mid 12s

 

im using those heads on my motor,they really like to run up top 3500 rpm and up,i had them on my carbed 355 11.1 motor before this tpi motor ,i think youll like them,i gave up a little on the bottom end but mid and top they were worth it.

 

Cool, I cant wait. I was going to see about taking it to an 1/8th mile track this weekend, but one of the guys got in a wreck on the way home from internationtal? in ST Lois last weekend and the passenger died. I didnt know him or most of the other guys I would have been going to the track with but as you can imagine people arent really in the mood to go since their friend just died.

 

Ok, I talked to the guy that built the motor, and he said that the pistons are stock. He said that the motor is out of a truck, and he thinks that they may have had a small dish, and valve reliefs. I dont know what to make of this or how to figure up the compression. He told me that he didnt think that the truck motors were dished as much as car motors. Anyway, I just need to figure out how to figure the compression. I really dont want to have the heads decked far enough that they wont be usable with respectable pistons, but then there is the fact that my next motor will probbly be the LT1 that I have in the garage and it wont use the same heads. Any imput on what I should do or what those pistons may be would be appreciated.

Ben

 

Common stock dished pistons are either 11cc's or 13cc's.
The deck clearance clearance ( nominal figure) on a stock motor is either .025" or .045" below the deck. Actually they often measure more like .055"....

Use the thin head gasket. It will help in the cr department.
I've used them for years on SBC's and BBC's with no problems.

RB may have had some bad experiences but most people don't.
Check the head and block before assembly for straightness
and be sure the surfaces are CLEAN...
Clean and lube the bolts with Black RTV and torque them accuratly and you won't have any problems.

U can calculate the cr here:

Compression ratio Calc

I would not start shaveing the hell out of the heads to get the cr up with dished pistons. Save it and rebuild the motor with the right flat top pistons and deck milling later.

 

My opinion...

I would not destroy a fine set of expensive heads, irreversibly, to compensate for them being used with a bunch of stock crap pistons. I would not build a motor out of mismatched parts, ruin the best of them to make up for the worst, and leave those best parts unusable with a properly built motor.

I would leave their deck alone and put them on that short block as it and they now stand; and run them like that, until the next shiort block rebuild time came around; and at that time, set the motor up correctly. If you hack the heads enough to "compensate" for the dished pistons, they will not be suitable for use on the motor they belong on — which is a zero-decked flat-top motor.

I would simply put them on the motor as they are, with a head gasket that I felt I could trust.

My opinion, for what it's worth.

 

Ok, this really sucks, because I used that compression calculator and it shows that if I use the composite head gaskets, and dont mill them that the compression could very between 8.4 to 9.1. This is calulating with deck clearance between .025 and .045 and the piston volume between -11 and -13 cc's. This is assuming that the head gasket bore would be the same as the engine bore(is this right?). I dont plan on rebuilding this motor, at least not anywhere in the near future. I have an LT1 that I will be using in the car when I get it done like I said.

My question, is do you think it would even be worth the money to put these on if I am going to lower my compression so much? Obviosly I will loose quite a bit of power without the compression, but how much? Sorry, this is just kind of frustrating. I know hp can be expensive, but does it really have to be such a pita? lol

Ben

 

ttt

 

Well Ben The 406 I just bought has the Sportsman ll's with a bunch of other Mods wich the builder claims 525hp at 9:1 compression.....Ive yet to verify this yet, The builder is Racing Heads Service.

 

The head gasket is bigger than the bore.
Common composite 350 head gaskets are 4.166" bore
and .039" thick compressed cc is 8.7 to 9.1.

Common steel shim gaskets are smaller 4.10" and .015" thick
compressed cc is right about 3.5"cc.

The motor will be more powerful with the Dart heads even though the cr will be lower. than you'd like.
Don't worry about it you'll still be WAY ahead of the game.
Do as RB says, bolt them on your motor as is.
Do as I say and use the thin shim head gasket and stop worrying about it. Just don't be a slob doing the install.
If it f***Cs up you can blame it all on me.....

Then get to work on a real performance shortblock for those those heads.

 

Ok, sounds like a plan, but I havent decided on the gasket yet. Anyway, to bad I just sold a roller 350 I had to my brother to replace his 305 that I think has bad rings. Oh well, maybe I will just build a nice 355 to put under here eventually and put the LT1 in something else that came with fuel injection origionally when I get it done.

Ben

 

Oh man, I am starting to get pissed. I recieved the heads a yesterday. Well, in the pictures he sent me he had one valve cleaned up "to show me that the valves were stainless". Well when I got them I looked inside the intake ports and the one that had the clean valve appeared to have recent porting done to it but none of the others did. Well, I poped out the intake valves and cleaned up the heads inside some. It appears to me that they only ported the one intake port and none of the exhaust on that head. I haveent taken the other head appart, but by looking in the intake ports it appears that they havent been ported either. It does appear that the heads may have been gasket matched though. My thing is that I was wanting something I could just bolt on for now. Also I havent done any porting myself before and I dont want to mess these up. I also dont have an air compressor or die grinder. I will say that the one intake port looks nice. It looks nice and blended and the valve guide has been teardrop shaped. None of the others have this treatment.

What should I do? The guy claims that it was a shop that did it, and said that they did all the work. He also said that he cleaned off the one vavle and if that is true then he had to know about this(if he didnt do it) because that one valve was clean on the inside and outside of the head and the others all have thick crusty carbon build up. Also the porting on the one port(same with the cleaned valve) appears like it had been done since the motor had been ran. It was real clean. I dont know if he just had his car at a real crappy shop or if he is trying to screw me. I know whoever built his car was a ****ing moron. They used some of the cheapest paper header gaskets I had ever seen and rtv'd them to the head or something(almost seemed tougher than rtv. You could still tell that the 2 center primairies had been leaking on both heads because of carbon on the heads. He claims that the shop still has his new motor and his car and are supposed to be putting it together and that he was going to go get all of his stuff from them before they mess it up but I dont know if he is just bsing or what.

Ahhhhhhhhhhhhhhhhhhhhhhhh!!!!!!!!!!!!!!!!!!!! I am going to flip.


Ben

 

Welcome to the real world , Ben!..Now .....you have a nice set of heads..chill out! Nothing you cant fix....do you have a didgital cam? Post some pics so the experts can lend you a hand.

 

As long as there is somewhat of a "funnel" under the valve seat
you're fine. The last angle of the "funnel" can/should be blended
into the port bowl. The short side radius should be a smooth radius from just below the valve seat , around to the floor of the port. You can carefully blend and smooth the other ports to match the one that is already done. Including the Valve guide boss.
This needs to be done to these heads.
As the sportsman valve guide boss is huge as they come.
These heads were intended to be ported so don't fret it.

The head should be "gasket matched" to what ever intake gasket you want to use. Usually a felpro 1205 or 1206.
You can measure the port opening and get the right gasket.
Your intake manifold should be opened up to match the head intake port openings. This is critical to these heads for some reason. (they don't like a step from a stock small manifold to
the larger Sportsman intake port opening.)
Post some pics if you can.

 

Well, I dont have a digital camera good enough to show the inside of the ports. I was going to try to take the pics to at least see if they would come out, but I think that my brother or someone must have done something with the camera. Anyway, I dont have the stuff needed to port these. How much does a good electric die grinder cost because I dont have much money right now. I just spent what I had saved up on these heads and an intake.


Ben

 

I am going to try to get ahold of a camera. You kind of worry me with the funnel thing. Could you explain a little better? Are you referring to the valve job?

I matched up my gaskets(1256) to the intake ports and it appears that they have already been gasket matched or matched these from factory. I have a performer rpm which is also very close to the gasket but could have a very slight amount of material removed. I guess it will just be longer till I get this stuff on, but it really just got on my nerves when i got them and they werent like I was told. I was hoping to put them on this weekend and measure pushrod length and order those in time to set the valve lash and go next weekend.

Anyway, I will see if I can get pictures but I need to find someone with a decent camera.

Ben

 

Also, I just noticed that the intake gaskets that you mentioned have larger openings than the one I have does. I just ordered what summit reccomended for this intake. Do you think I should get a different intake gasket and match to that. I also like the idea of not having the exhaust/heat crossover holes since I have headers and dont use them.

Ben

 

As long as your intake gasket matches the ports now, further enlarging is not nessessary for your purposes. ( the gasket can be slightly bigger.)
Just match the intake manifold port openings to the heads now.

There should be 3 distinct valve job angles. like 30/45/60
plus a bowl cut usually 75 to 85 deg. this blowl cut can/should be hand blended into the port bowl.
The 45deg angle is the seat angle. Lightly spray paint or color the valve seat in the head with a magic marker then spin the valve in the seat to show the seat angle. A strong light helps.
As long as the bowl is not exessively hogged out you're fine.
Just make all the rest of the ports the same.
Excessive enlarging is not nessessary. The exhaust port doesn't need to be bigger either.
You want an electric die grinder. I use a sears one.
You can do this whole job with a few stones.
Polishing is not recommended on the intake port.

 

Ok, it does have different angles on the head, but not on the valve. Is this the way it is supposed to be? The one intake that is ported doesnt look like the bowl is hardly any bigger than the others, just like it has been streemlined and blended, and the valve guide boss is trimmed. Do you have any idea how much an electric die grinder is?

Ben

 

I talked to sears on the phone and they said that they didnt have any electric die grinders only air powered. This is the only one I found on their site.

Craftsman Die Grinder

Would this work, and what model do you have?

Ben

 

Ben, I have a craftsman you can have for $50..hardly any time on it at all....you can get a new one for around $100..let me know.. the onwe in your pic is the one I have...

 

Does it seem to work good for porting? I may consider it, but it may be a couple of weeks before I have the money. It looks kind of big, is it hard to work with?

Ben

 

That, would be the one.

 

Hey, I think I will take it. It will be at least friday before I have the money though. It could be a week from friday though.

Ben

 

Ill shoot ya an e-mail with my address, this evening.

 

Ok, now I have access to a die grinder, I need to know what kind of bits I will need to do this porting. I niticed that in sitting bulls thread that some cutting bits were used, but, I think that if you buy the standard apbrasives kit it just comes with stones for the porting and then all the other stuff like the sanding rolls and such. Will the stones take away the metal fine where I need to like around the valve guide?

Thanks

Ben

 

it will, Ben It will just be a little slow...the carbide cutters are best... Here are the ones you need