New heads

[HawkX66]

I've been looking to get some extra power out of my 69 Camaro. I'm running a 408 (402 +.030) I R&Rd the heads on it last weekend, but then I calculated what the compression ratio would be when I put it back together. 8.3:1... My new cam wants 9:1 or better so I picked up some 290 heads for $200 last night. I think I did pretty good all things considered. Now the question is, what to do with them? Most of the seats are perfect, but two have a couple of small pits that I'd like to see gone. Should I replace all the seats with hardened seats and re-use my 2.06/1.72 valves or should I go to 2.19 or 2.25 valves? Money is an object... What would I be looking at in machine shop costs for either option? I don't have much for machine shops near me to I'll need to go closer to Detroit I think.
I compared the factory pistons in my born with 350hp 396 to the replacements that are in the 402 I'm playing with. There should be zero clearance issues. The replacement pistons are supposed to be a stock replacement piston, so I figured that was the case.
Thanks for any input.

My virgin born with 396 piston compared to the replacement Silvolite 1445

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/69%20Engine%20350hp%20415%20lbft%20L34%20Motor/20160929_161623_1.jpg (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/69%20Engine%20350hp%20415%20lbft%20L34%20Motor/20160929_161623_1.jpg.html)

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/72%20402/20160910_192923.jpg (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/72%20402/20160910_192923.jpg.html)

New Heads 3964290 (H 11 9 & I 23 9 A month newer than mine)

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_162047.jpg (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_162047.jpg.html)

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_161906.jpg (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_161906.jpg.html)

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_161912_1.jpg (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_161912_1.jpg.html)

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_162106_2.jpg (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_162106_2.jpg.html)

My new cam & springs. Head gasket will be .020.

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/72%20402/20160925_120816.jpg (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/72%20402/20160925_120816.jpg.html)

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/72%20402/20160925_120747.jpg (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/72%20402/20160925_120747.jpg.html)

[ssl78]

Changing valve seats on a big block Chevy is very risky since it is very easy to go into the water jacket. Then your head in junk.

[HawkX66]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ssl78</div><div class="ubbcode-body">Changing valve seats on a big block Chevy is very risky since it is very easy to go into the water jacket. Then your head in junk. </div></div>
I thought that was a pretty standard practice. Do you mean enlarging them is risky?

[VintageMusclecar]

Do NOT try to have hardened seats installed unless it's absolutely necessary--there's water JUST under the valve seats on a BB head and it's easy to break through when cutting the seats for the insert. I would go to a 2.19 on the intake but leave the 1.72's in the exhaust. If it's in the budget, a pocket port job and a little chamber work will pick up a nice little chunk of power.

As far as that cam goes--that's going to be a pretty lumpy cam in a 402. You're going to need a 3500 converter or a 4 speed and a 4.10+ gear to take advantage of it.

Also, do not take for granted it will have sufficient piston to valve clearance--you really need to check it with those rebuilder pistons as the reliefs tend to be fairly shallow.

[HawkX66]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VintageMusclecar</div><div class="ubbcode-body">Do NOT try to have hardened seats installed unless it's absolutely necessary--there's water JUST under the valve seats on a BB head and it's easy to break through when cutting the seats for the insert. I would go to a 2.19 on the intake but leave the 1.72's in the exhaust. If it's in the budget, a pocket port job and a little chamber work will pick up a nice little chunk of power.

As far as that cam goes--that's going to be a pretty lumpy cam in a 402. You're going to need a 3500 converter or a 4 speed and a 4.10+ gear to take advantage of it.

Also, do not take for granted it will have sufficient piston to valve clearance--you really need to check it with those rebuilder pistons as the reliefs tend to be fairly shallow. </div></div>
Thanks a lot Eric. That answers that about the valve seats anyhow. I always thought hardened seats were a must have in the long run. That'll save me some cash now. I didn't realize they were that close to the water jackets. I was planning on leaving the exhaust. Thanks for confirming it. Now all I'll have to do is concentrate on the intake valves. Going up to 2.19 will take care of the couple of small pits I saw. Perfect. That was the big reason I was looking at changing the seats.
I'd love to port them etc, but that'll will have to wait for another day. The cam is what Comp Cams recommended, so that's what I went with. I do have a 4 speed, so I'll be good there. Only factory 3.31s though...
I definitely wasn't going to take clearances for granted. Even though I'm sure they're ok, I'd still double check it.
I know she's not going to be a 10 sec car, but I'm alright with that. I was just looking for a lot better than the truck heads and smaller cam I've been running.
This was some great info. I really appreciate it. Obviously I'm just getting into learning about heads, cams etc...

[WILMASBOYL78]

Great advice from Eric...those 290's are a semi-open chamber design and with a little work, they will help make some decent power. As he mentioned, that is a lot of cam for a baby rat...I would consider something else if you can.

I don't understand the compression calculation?? if you are using 396/350hp pistons and the closed chamber heads, the factory ratio would have been 10.25 to 1. How do you get down to the 8's <<GRAEMLIN_URL>>/dunno.gif

Check with Eric on a cam recommendation and make sure you have the compression ratio figured correctly.

-wilma

[ban617]

Since they are semi open won't the compression ratio be lower ?

[WILMASBOYL78]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ban617</div><div class="ubbcode-body">Since they are semi open won't the compression ratio be lower ? </div></div>

The #290 head was a closed chamber head that the factory added a little 'breathing room' to. It was used on the 396/350hp and 454/360hp big block applications in 1970. It was identical to the #063 used in 1969 except for the newer 'peanut spark plugs'.In both cases the advertised chamber volume [101cc] is the same in these heads and even #215 which came before that. These heads were all designed to work with a small dome piston that produced a 10.25 to 1 compression ratio.

As was mentioned, they are a great platform for a street build...with a little work these oval ports, combined with other properly selected pieces can really make good power.

-wilma

[earntaz]

I am running 063 and they have ccd a skoshi over 100 cc. Totally agree with Wilma ... TAZ

[HawkX66]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: WILMASBOYL78</div><div class="ubbcode-body">Great advice from Eric...those 290's are a semi-open chamber design and with a little work, they will help make some decent power. As he mentioned, that is a lot of cam for a baby rat...I would consider something else if you can.

I don't understand the compression calculation?? if you are using 396/350hp pistons and the closed chamber heads, the factory ratio would have been 10.25 to 1. How do you get down to the 8's <<GRAEMLIN_URL>>/dunno.gif

Check with Eric on a cam recommendation and make sure you have the compression ratio figured correctly.

-wilma </div></div>I hear you guys on the cam. I contacted Comp Cams when I bought it, and it's what they suggested. Lunati suggested something similar, but solid lifter. I'm not using my L34 motor. She's bagged and stored in the corner. The 402 +.030 (408) short block I'm using has Silvolite 1445 pistons at -8cc. They're in the second picture. I'd swap out the pistons for some more like the originals, but I'll eventually build a bigger cube engine I'm sure. This should be fine for a while to keep a grin on my face.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: WILMASBOYL78</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ban617</div><div class="ubbcode-body">Since they are semi open won't the compression ratio be lower ? </div></div>

The #290 head was a closed chamber head that the factory added a little 'breathing room' to. It was used on the 396/350hp and 454/360hp big block applications in 1970. It was identical to the #063 used in 1969 except for the newer 'peanut spark plugs'.In both cases the advertised chamber volume [101cc] is the same in these heads and even #215 which came before that. These heads were all designed to work with a small dome piston that produced a 10.25 to 1 compression ratio.

As was mentioned, they are a great platform for a street build...with a little work these oval ports, combined with other properly selected pieces can really make good power.

-wilma</div></div>
These heads were also used in 69 at least on the &quot;C&quot; prefix motors which started ~July. My born with motor is a &quot;C JF&quot; coded or 350hp 396 4 speed built 7/28/69. The heads are original to that motor.
I did a lot of reading on the 290 heads after a lot of guys told me I should use my originals. The high reviews they got for being iron convinced me to buy this set. I figured for $200 I'd be doing ok. I'm going to put 2.19 valves in and leave the 1.72 exhaust.
I just re-curved my distributor this weekend. Here's what I came up with. We'll see if 20* initial is too much...

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/72%20402/ChartGo.png (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/72%20402/ChartGo.png.html)

[WILMASBOYL78]

Dave...I have always set initial in the 16-18* range and total at 36*..all in by 3,000 rpm. Each motor likes something a little different...time will tell what works best. Sounds like a fun project.

-wilma

[HawkX66]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: WILMASBOYL78</div><div class="ubbcode-body">Dave...I have always set initial in the 16-18* range and total at 36*..all in by 3,000 rpm. Each motor likes something a little different...time will tell what works best. Sounds like a fun project.

-wilma </div></div>
Thanks Wilma. We'll start there and see what happens.

[Salvatore]

hardened seats not necessary Dave.

[EZ Nova]

<span style="font-weight: bold"> As per Mark Jones (VortecPro) and MYSELF, DO NOT GO 2.19 VALVE WITH THE SMALL BORE 396/402'S!!!!! </span>

The Valve are too close to the cylinder wall, and as Mark's own words &quot;FLOW LOSS WOULD BE HORRIBLE&quot;. There is no way that this engine would require any more then 2.06 intake for what you're doing.The bigger valve DO help quite a bit, but they need the bigger 4.250+ bore to actually work. The narrow bore of this engine would actually HURT performance. You're far better off doing some port work then paying for new valve and and related machine work.

Now on my lil 402, I used ported sq port head and comp 660 roller. It ran strong, 10.47 in '69 Nova. So I think the cam should be fine for wht your doing, just do NOT open those heads with the small 4.094+ bore.

[HawkX66]

Thanks a lot John. I'm actually just heading to the machine shop now. That's the first time I've heard that. What you're saying makes sense, but I've talked to quite a few guys that have flowed these heads with the 2.19s and they said they flowed well. I don't know what to think because obviously I don't know better either way. I have a 4.155 bore. It's a 40w bored .030 over.

[EZ Nova]

I personally have felt this way for a while. BUT I recently seen Mark's comments on this over on TC.

Mark's on here as well, you could PM him and get his insight as he's really good with GM iron ovals, as most know. Do some math, you have 4.155 bore. Minus (2.06+1.72). That only leave you with .375 OVERALL space in the bore. Now take away another .130 for the 2.19 valve, and you have .245. So it does get tight on the &quot;bore-side&quot; of the intake valve. This is the issue with the bigger valve in the small bore 396/402 blocks. Even RFD has a different head for max performance on small bore 4.250+ blocks.

There was a thread over there where Mark told a guy NOT to use even an aftermarket AFR oval head even. Same thing, YES they can flow, but from MY UNDERSTANDING from my guy, is that the flow backs up the one side of the valve on the 4.096-4.155 bore stuff. Unshrouding of the valve plays a major part in making Hp. You not trying to make 650-700Hp here, so don't go through the added cost of valve/labor! PUT those funds towards a good port on what you have. They will support 650+Hp in that form of ported/2.06 valve combo.

[WILMASBOYL78]

I think these tech discussions are great...in fact, it is one of the things I like about the TC site...lots of 'motor heads' swapping recipes.

Neat stuff..

-wilma <<GRAEMLIN_URL>>/biggthumpup.gif

[HawkX66]

I love them too. I'm learning a ton. So here is my &quot;dilema&quot;. I'm sitting here at a coffee shop deciding what to do. I talked to the machinist. Good guy that builds racing engines.
I was mainly going to 2.19 because of a little pitting on two of the intake seats. To go 2.19, clean, surface the heads and set up the valves, it would cost me $525 in labor if the guidesite are good. He mentioned going aluminum like everyone else has. My problem is that with the pistons I'm running I'd need a 100cc or so chamber. All the aluminum heads with 100cc chambers that I've seen are north of $2k. I could have a real nice set of heads, but iron for less than $1k.I can handle spending a little more if it's what I need to do, but I don't want to waste cash... One more thing, I plan on going bigger cubes at some point, so going 2.19 might not be right for the 402, but it would be when I swap them over to a igger cube motor right? I'm not planning on competing with this set up.

[WILMASBOYL78]

If you plan to use the heads again on a larger engine...then do the 2.19 upgrade and other work now and it will save you time/money down the road.

-wilma

[VintageMusclecar]

Funny, the L78's sure seem to run awfully damn good with a 2.19 intake valve (and 1.72 exhaust).

Guess the factory got that wrong?

Both edges of the chambers (intake and exhaust side) will overhang the perimeter of the bore. If you look at the deck surface of your block you will see the factory cut reliefs on both sides to address this:

http://www.yenko.net/ubbthreads/pics/usergals/2016/10/full-1124-49902-402_bore_notches.jpg

Just for reference, here's a view few people take the time to see--the chamber bolted to the block from the piston's view (this is from my own 496):

http://www.yenko.net/ubbthreads/pics/usergals/2016/10/full-1124-49903-032.jpg

For those who imply a 2.19&quot; is too &quot;big&quot; for a 402, may I remind them of this--the BOSS 302 and 351 Cleveland also used a 2.19 intake valve (--on a 4&quot; bore!), and those engines are nothing to sneeze at.

As usual, take it FWIW.

[EZ Nova]

I know my thoughts, and sometimes I'm out in left field. I know Mark is pretty damn good with the GM ovals and he posted in this thread:

http://www.chevelles.com/forums/13-performance/788849-450-470-hp-my-402-bbc-2.html

Post #24
&quot;You don't put 2.190 intake valves in a 4.155 bore, unless you want to kill the engines potential.&quot;

Now would I tell him to toss his L-78 heads if he had them, probably not. Will it make power, YEP, been there done that. I'm was just pointing out for what he's looking at doing, and parts he has, with a limited budget, the $$$ would be better spent to port what he has and keep the 2.06's.

Eric, you know how to make some power too from what I've seen. I just think the return on investment might be better served keeping his 2.06's? This is partly what these forums on different site are meant to do. Open up &quot;friendly&quot; discussions as there are always many different way to reach a given result. And I would have fully agreed with a MIN of 2.19 intake on a 30 or 60 over 4.250 block. But with this narrow 4.155 bore, limited budget, and not shooting for the moon, I just think personally I would go with a port 2.06 over a non port 2.19 in this head ON THE BORE SIZE.

It's ok if we disagree, I'm Canadian and your an American. It happens LOL

[HawkX66]

I appreciate everyone's input. I took the heads home with me to do some more thinking and research on it. Basically where I am right now is thinking I have three real choices:
1. Try to lap the valves the way they sit and save money for another day.
2. Have my heads done with 2.19 valves. ~$700 or so labor and parts. I'd have less than $1k in the whole set up.
3. Keep trying to find aluminum heads with ~260 - 270cc runners, 2.19/1.72 valves and ~100cc chambers for less than $2k.
I'm going to try for #1, but I think I'll end up with #2.
Don't stop the conversation if you have anything to add. I appreciate any knowledge you guys are willing to share.
By the way, this is the seat that concerns me and the reason I think I need to go to 2.19 intake.
It looks worse than it is, but it's still not good obviously. All the others are clean.

http://i1164.photobucket.com/albums/q573/SgtHawkUSMC/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_161947_1.jpg (http://s1164.photobucket.com/user/SgtHawkUSMC/media/69%20Camaro%20SS396%20L34/72%20402/290%20Heads/20160929_161947_1.jpg.html)

[VintageMusclecar]

That seat is toast, don't try to run it like that! Lapping that seat will NOT clean that up! It's right smack dab in the middle of the 45° cut.

You'll either have to (A) sink the valve job to clean that up (BAD idea!), (B) have seats installed (another bad idea as discussed earlier) or (C) have the seats cut for bigger valves.

[HawkX66]

That's what I figured. C it is.I thought that I might get enough of the seat to seal by lapping it just to run them for a while.
Just out of curiosity, what would happen if I did clean it up a little and ran it? A little loss of compression or something more serious?

[HawkX66]

Nevermind. I just found this which describes what happens with a bad seat.
&quot;The other common type of valve failure is valve burn, or burnt valves. Essentially this is caused by combustion gases escaping between the valve and valve seat when they are not sealing correctly. The hot combustion gases are forced past the valve which starts to burn away the edge of the valve, progressively getting worse the longer it is left without being rectified. Normally this type of failure affects the exhaust valves only, but it can also damage the intake valves.

A burnt valve will cause issues with your vehicle’s performance and fuel consumption. Rough idle, reduced power, backfiring, and misfire are all symptoms of valve burn.&quot;

[earntaz]

That seat WILL NOT clean up via lapping -- loss of compression will be the result. TAZ

[HawkX66]

I didn't think it would completely clean up, but I thought I could get enough of a seat to seal for a while.
I won't run them unless I get the 2.19 valves installed.

[WILMASBOYL78]

Well....that ends the discussion. Reality trumps opinion on this one <<GRAEMLIN_URL>>/rolleyes.gif

Looks like the bigger valves are the best choice.

Good luck.

-wilma

[HawkX66]

Agreed. Thanks all. I'll let you know how it turns out.

[HawkX66]

Just to add one more thing to this... I've been scouring the Web looking for aluminum heads that would fit the bill. I have found zero that would. The closest I could find are Edelbrock heads. They're 100cc and 2.19 intake, but 1.88 exhaust. $2,400 a pair! The bare are $1,600 and need a valve job.
Am I missing something? Looking in the wrong place?

[WILMASBOYL78]

You aren't missing anything...

Less is More <<GRAEMLIN_URL>>/rolleyes.gif

-wilma

[VintageMusclecar]

Properly prepped, your oval ports will provide you with ample performance--you'd be hard-pressed to justify the cost of a <span style="font-weight: bold">good</span> set of aluminum heads (read: NOT Chinese castings) over the iron units.

[HawkX66]

I agree about the ROI with buying aluminum though. I just can't justify the cost from what I've learned. I see only two real advantages with them for me right now. 1. Weight. 2. Hardened seats. Maybe they flow better, maybe not.