#4448308 heads have any potential?

[Nick M.]

I have a pair of these heads complete, they have been cleaned and checked and are crack free... just wondering if they are worth rebuilding. I am on a tight budget so i will most likely be stuck with a stock type cast iron head, they will be going on a fresh 0.030 360 with kb107's

 

[rumblefish360]

Yes, absoulety. However, there max potentail from what I have been told is not as good as a older head. This may be the head or the porter. Excellent results are still obtainable even with the 1.88 valves.

MP used to sell these as performance heads and used to have templates to port them. There porting templates may still be available and there designed for the 1.88 valve only. MP has said there template ported small valve head has the abilty to make up to 100 HP over unported heads. Of course, at this level, there pushing the head/engine combo hard.

 

[moper]

they are IMO the best LA head you can use. The earlier heads have a decent intake port but the exh sucks. The 308s use the exh port the Magnum heads were developed from. I run larger intakes because a new bigger valve is the same cost and the seat angle can be brought up and out to the edge of the factory seat. Bowl blend and gasket match the intake side. Remove the AIR bump, enlarge the exh by about .060 on the sides and roof, and blend that back without touching the port floor. Then tap the AIR holes at the flange and use red locktite tp seat grub screws in the holes.

 

[dodge freak]

MP used to sell these as performance heads and used to have templates to port them. .

And I found a set on Ebay for $300 with the 2.02 intakes. Guy had a BIN and I was the 3rd or 4th person to looked at the page two hours after he posted it. :cheers:

 

[dodge freak]

they are IMO the best LA head you can use. The earlier heads have a decent intake port but the exh sucks..

Higher compression helps push the exhaust out. So yes on the street with lower compression the exhaust would flow much better. But what about race motors with 14 to 1 compression? This is where the older heads ported right can outperform the 308 heads with those too large pushrod holes that blocks the flow.

Remember the bigger the cam and rpms the more a large intake port helps. The 308 intake ports are restricted more than the older heads.

 

[1wild&crazyguy]

they are a good head, like said the exhaust is better than the older head and is not so touchy when ported.
the intake port flows decent, though it runs out around the 250's, still really good for a production head.
They are a lil thin as they were getting into finding ways to save money by making thinner castings, like the magnum head, so you need to be careful when max porting and increased milling like .040 or better.

for a guy looking for 240's cfm & 180's [easy] cfm flow on the exhaust, they[308's] are the ticket.

I would like to find another set of the old A cyl head mopar used to sell [non ported version], it was 'like, but not identical' to the j head port with out the massive straight wall transition/bump but with a larger then but same shape magnum exhaust port.

I still have a # for a guy with a set of the factory ported 'A' head version advertised at [email protected] lift. He was at spring fling trying sell them.
I tell ya....that factory port job was the ugliest thing I'd ever seen and a testament to who says it has to look pretty to flow [if they really flowed what they said]
it looked like a templet job with alot of un even short turn work, like a couple of grooves ground into the ssr/fsr...and then like someone just let go of the grinder all together.lol

oh and yes it's harder to get it in than it is to push it out..

 

[2 Darts]

Higher compression helps push the exhaust out.

How? Exhaust is a function of the flow of the exhaust side of the engine while the valve is open. The exhaust gets some assist from the intake which will let in cool fuel vapor to displace the exhaust gas during the valve overlap period. Little to no compression happening at this time.

Race motors typically have a lot overlap in which both intake and exhaust valves are open. This allows the heavier, cooler intake charge to displace the less dense, hotter exhaust gas in the cylinder. The open exhaust valve and downstream passages allow the exhaust gas to escape and evacuate the cylinder. The engine builder will specify or select a camshaft that will allow the engine to produce optimal power within the rpm range required by the application with an eye also on how long the engine has to live.

 

[1wild&crazyguy]

How? Exhaust is a function of the flow of the exhaust side of the engine while the valve is open. The exhaust gets some assist from the intake which will let in cool fuel vapor to displace the exhaust gas during the valve overlap period. Little to no compression happening at this time.

Race motors typically have a lot overlap in which both intake and exhaust valves are open. This allows the heavier, cooler intake charge to displace the less dense, hotter exhaust gas in the cylinder. The open exhaust valve and downstream passages allow the exhaust gas to escape and evacuate the cylinder. The engine builder will specify or select a camshaft that will allow the engine to produce optimal power within the rpm range required by the application with an eye also on how long the engine has to live.

:read2:
besides high psi seeking low and the vacuum effect flowing....exhaust scavenging pulls the intake in, overlap=both valves open at the same time.

ever wonder why a chey sb stinks so bad? why they had smog pumps 1st?
cause the intake flows so much less then the exhaust, the exhaust over scaveneges and begins pulling more/too much and you end up with mix/fuel going right out the tail pipe.

 

[Prine]

nah their not worth their 62lbs each....

Just box em up and send em to me.....8)

 

[Cooter]

Yeah, all my junkyards are money driven and crush stuff before the dust even settles on it. Won't you have pity and send me those heads?

 

[moper]

Higher compression helps push the exhaust out. So yes on the street with lower compression the exhaust would flow much better. But what about race motors with 14 to 1 compression? This is where the older heads ported right can outperform the 308 heads with those too large pushrod holes that blocks the flow.

Remember the bigger the cam and rpms the more a large intake port helps. The 308 intake ports are restricted more than the older heads.

High compression and/or "race engines" would be incredibly foolish to use a head like this. If you're trying to get 280cfm from old iron it better be a labor of love or to fit class rules. Because there's no reason to use them asied from those two.

 

[rumblefish360]

Higher compression helps push the exhaust out. So yes on the street with lower compression the exhaust would flow much better. But what about race motors with 14 to 1 compression? This is where the older heads ported right can outperform the 308 heads with those too large pushrod holes that blocks the flow.

Remember the bigger the cam and rpms the more a large intake port helps. The 308 intake ports are restricted more than the older heads.

High compression and/or "race engines" would be incredibly foolish to use a head like this. If you're trying to get 280cfm from old iron it better be a labor of love or to fit class rules. Because there's no reason to use them asied from those two.

OMG! Moper, you took the words right outta my mouth.

OK, Dodghe Freak, unless class rules dictate this heads use or your just a wild and crazy nut like a few of use here, theres ways around these issues and you have to be cresative on how it's done. Theres a few angles to attack this on. Cam shaft profiles/timing events need to be custom taylored for use of heads like this. 14-1 on a iron head is a real serious effort and seriously, one that I have not heard of before since super serious efforts like this are rare due to the cost of everything from start to finish never mond a campaining.

(Sorry about the run on sentence)

Also, creative head porting, angle milling and big tube headers, huge valves help.
Redesigning the port is the ultimiate direction to take. And cost.

At this level, it doesn't matter what head you have, it's gonna get torn up and redome like clay scultures.

 

[rumblefish360]

OH and how far any given head can be ported out should be shown to a super pro in this feild with full disclosure of specs. Not here I thinks.

 

[Guitar Jones]

Those things are junk and should be sent to me.

Sincerely,

stroked340

 

[moparornocar72]

I think I have or had a set of these laying around, i'll have to check. I put a set of them on my last 440 build for a charger rallye and put the 1.81 2.14 larger valves, 3 angle valve job, port and polish, they flowed nicely!!!!!

 

[Nick M.]

This is great news, i picked up the pair for 150 bucks to replace my cracked originals. The shop said they will need a valve job, new guides and possably hardened exhaust seats. I know they came with hardened seats, but i was told that they are sometimes thin and may not be hard enough after the seats are cut?? This car wont see more than 4-5k miles a year but I will be going to the local 1/8 mile occasionally on the weekends, will they live for a while if I skip the seats?

 

[Nick M.]

So what should I expect to pay for this kind/amount of work? I am looking for a machine shop to do this work as well, would be nice if it was in driving distance of San Diego CA any recommendations?

 

[dodge freak]

$400 plus parts ..that is no seats.

I really would chance it and not install exhaust seats. They can drop out after a while--cause big problems. All it takes is one.

 

[1wild&crazyguy]

I think you should start a new thread.

this ones fk'd up already from what I'm reading

 

[moper]

Cost depends on the shop you chose. If they have talented guys with good or great equipment, it will cost more. It takes about $1200 to get a set of iron to what I consider "ready to run" on a performance engine. That includes pricing for dual springs and Comp or Crane retainers and locks, stainless performance valves, etc. As for labor, this is what and why: I always do hardened exh seats. The factory stuff is induction hardened. But as you note, valve jobs and wear can lower the protection. On top of that you're adding (usually) a narrower seat for flow (means it gets hotter and wears faster) and much heavier springs. I always do guides or liners. Because the seat cutting equipment uses a straight pilot and if the guides are marginal, the seats will suck as a result. If the shop uses tapered pilots, find another shop. I always cut the guides down if liners are used, and I always cut the spring seats for dual springs. It just makes sense to me to do this stuff while it's apart. Because it's almost inevitable that at some point the guy's going to want to upgrade a cam or whatever and need it done. Plus, IMO, the positive seals do a better job controling oil into the chambers. I always have a 5 angle valve job done. This includes two additional angles: one is the throat cut that basically does a bowl hogging removal. The other is an unshrouding cut in the chamber that pushes the chamber walls back slightly and having both those done at the same time as the seats means the angles are cut concentric and round. These two angles don't cost any more if the shop does performance work because they have the cutters already and the result is more than a "stage one" porting job but not quite stage two.

 

[1wild&crazyguy]

ditto, do the guides then valve job.
prices vary, the range can be 600-1000 around the west cost for the above work
I like the top chamber cut moper mentions but don't sink the valve in order to get the bowl cut perfect, the more transition from bowl /seat/ chamber the better.jmo


I was worried for sec there...

 

[Nick M.]

My combo is fairly mild compared to most, a 0.030 360 stock crank and rods, kb 107's block is not zero decked just cleaned up. Compression a 91 octane friendly 9.0:1 comp xe268 cam.
While i would love to go all out and build a set of top notch heads.... I just dont have the money. Around $600 give or take a few bucks is much more realistic than 1000.00. I had planned on using the stock valvetrain except for new springs and replacing the exhaust valve rotators with standard type. What modifications would be most beneficial on a tight budget? going with a larger intake valve? 5 angle valve job?
My power goal is an honest 360-375 horse 400+ ftlbs from what i have read here it should be possable, hope i'm not being too unrealistic

 

[dodge freak]

You need to have the heads looked at.

If the guilds are in fact bad replace them. Its needed for a tight valve seal that last.

5 angle valve jobs are not needed. Sure the heads might flow a bit more but guilds and a normal 3 angle valve job will last a long time and still flow ok.

I would skip the 2.02 intakes unless the intake valve need to be replace-unlikely.

Same with harden seats. Even heads without any type of hard exhaust seats will last a couple of years before the valves sink.

So I would have the heads disassemble and new guilds and a performance valve job and new springs and retainers-locks too.

 

[1wild&crazyguy]

You need to have the heads looked at.

If the guilds are in fact bad replace them. Its needed for a tight valve seal that last.

5 angle valve jobs are not needed. Sure the heads might flow a bit more but guilds and a normal 3 angle valve job will last a long time and still flow ok.

I would skip the 2.02 intakes unless the intake valve need to be replace-unlikely.

Same with harden seats. Even heads without any type of hard exhaust seats will last a couple of years before the valves sink.

So I would have the heads disassemble and new guilds and a performance valve job and new springs and retainers-locks too.

I agree in ways, it's a tough decission to make between a 5 angle and ...I mean, in most shops out here they pretty much do the 5 angle on anything performance based..it costs around $175-$225, yes guides are a must, for they won't do the VJ if the guides are trashed..= centers the chuck.

as for power/flow...well we do know that just cause the heads flow 240 doesn't mean they do after the inake and cab go's on, so....this is where exaggerating the flow beyond 240 to like 250-260 in order to get an actually 240'ish port flow with everything bolted up.

every 5 cfm is worth 10hp, so add up what you need for your goal and keep the rest in mind for how much extra you'll need.
oh and.definitely do the hard seats, they'll sink in 10k'ish of hard [wot] driving.
jmo

 

[rumblefish360]

Nick M

hope i'm not being too unrealistic

I honestly do not think your being so. How far below deck are the pistons? Is 91 octane the best Cali has?

I don't know what the machineing cost would be in your state or from your machinest. They can vary widely here. I've been quoted a difference of $400 for balanceing the rotating asembly.

I think for the whole head package, if your valves are good and a good valve job is done, 3 angle or 5, (the low lift flow is important and easy to enhance while the VJ is being done,) I'd ask how much a bowl porting is and try and get it done. And call it a day.

Most street builds work excellent with just a good basic VJ and a bowl porting.