school me on magnum heads

Posted By: jamesc

school me on magnum heads - 12/09/12 04:31 AM

i may be working on a set of magnums in the future and am way out of the sb curve. i know they're metal, use a different intake pattern and valve gear.

this will be a minor port match/cleanup and backcut the valves deal.

i get the impression the RT head was never used in production only aftermarket, and they're not to be found?

Posted By: qwkmopardan

Re: school me on magnum heads - 12/09/12 07:59 AM

If they have any miles on them, they will more than likely be cracked beyond repair between the seats. I have had several sets dropped off for rebuild and porting and have yet to do a set. I set them up with a good set of LA heads and oil the rockers like a BB Indy head except through the rear shaft bolt with a 3/32" hole drilled from the bottom up. I do think there are affordable aftermarket magnum heads now. Engine Quest I believe.

Posted By: 67_Satellite

Re: school me on magnum heads - 12/09/12 02:18 PM

I did an ultra low budget fix on a set for a local guy.They had cracks but still don't leak to this day.

I don't know if they all do that or if we got lucky.

Posted By: 70Cuda383

Re: school me on magnum heads - 12/09/12 03:14 PM

they say every set of Magnum heads cracked. but yet look at how many of them are on production trucks running 200k+ miles. (check the truck section for the recent thread on "how many miles on your magnum engines")

clean up the valve guide boss, open the bowls, and remove some from the pushrod pinch, and you've got a 230 CFM head. especially if you upgrade to the 2.02 valves over the stock 1.92

Yes, the R/T heads were NEVER production line heads, despite much internet rumor and poorly researched/written magazine articles. I've had guys send me messages on YouTube, because they see a video where I rebuilt a 5.9 out of a Dakota R/T, and they were drooling over the idea of picking up my "R/T heads" for cheap.

they do pop up now and then on forums, such as the parts ads here on Moparts, or on Dakota-Durango.com or Dakotart.com etc.

there are quality iron castings available from Indy, Hughes, etc. and they're not all that expensive (around $600 a pair, bare), plus as cast, they flow better than stock production magnum heads.

and of course, there are aluminum Edelbrock RPM heads for the Magnums, they're a 450-500 hp head, right out of the box, but are prone to poor valve jobs just like all the edelbrock heads.

Posted By: Crizila

Re: school me on magnum heads - 12/09/12 03:37 PM

Quote:

there are quality iron castings available from Indy, Hughes, etc. and they're not all that expensive (around $600 a pair, bare), plus as cast, they flow better than stock production magnum heads.

I've been running a set of Hughes "iron ram" magnums now for about 5 years with good success. Just had them reguided. They are fulley ported 2.02 / 1.60's that probably flow in the 260/270 range. Quality pieces for the $.

Posted By: moparacer

Re: school me on magnum heads - 12/09/12 05:17 PM

Just went through the this with a set of magnum heads I used on a engine for my Barracuda.They were new castings, but I would have never used them if they had a lot of miles on them due to the cracking problems.

The biggest problem beside the cracks is the valve spring selection. If you are going to retain the stock valves like I did there are only a 2 or 3 choices, and I had to buy seat and guide cutters to get the installed height and retainer to guide clearance right.

Quote:

clean up the valve guide boss, open the bowls, and remove some from the pushrod pinch, and you've got a 230 CFM head. especially if you upgrade to the 2.02 valves over the stock 1.92

Yep, I spent a few evenings working on mine and got them to 230 @ .550 with 1.92 valves.

Posted By: SpareParts

Re: school me on magnum heads - 12/09/12 07:45 PM

I had 3 pairs, all 6 were cracked. Iron ram's from Hughes would be my choice

Posted By: cudadoug

Re: school me on magnum heads - 12/09/12 09:46 PM

The iron ram heads from Hughes are what...the EQ heads? The EQ and RHS head are the best bang for the buck small block out there staying below 600 hp. The RHS even has the advantage of coming in a version that is the magnum design with the provisions to use LA rocker gear. Both come drilled for either the magnum or LA intake.

I can tell you that both the 2.02 RHS and EQ head outflowed the OOTB Eddy head on the bench we use. We also found that rubbing on the same spots on the EQ has we did on the RHS heads, the EQ's actually had a little better flow in the mid lift area.

The only knock I have is like OE magnum heads, the seats need cut and the guides trimmed to run any valve spring other than what will limit you to about 525" lift...

Posted By: patrick

Re: school me on magnum heads - 12/11/12 02:18 PM

Quote:

The iron ram heads from Hughes are what...the EQ heads? The EQ and RHS head are the best bang for the buck small block out there staying below 600 hp. The RHS even has the advantage of coming in a version that is the magnum design with the provisions to use LA rocker gear. Both come drilled for either the magnum or LA intake.

I can tell you that both the 2.02 RHS and EQ head outflowed the OOTB Eddy head on the bench we use. We also found that rubbing on the same spots on the EQ has we did on the RHS heads, the EQ's actually had a little better flow in the mid lift area.

The only knock I have is like OE magnum heads, the seats need cut and the guides trimmed to run any valve spring other than what will limit you to about 525" lift...

yup, hughes "iron ram" heads are enginequest 318A and 318B heads (magnum and LA intake pattern)....both use magnum pedestal mount rockers.

the RHS heads, the magnum version has magnum intake pattern and magnum rocker gear provisions, the LA version has the same ports and chamber, but LA intake bolt pattern and LA rocker gear provisions.

I think most of the cracking issue with magnum heads is due to the induction hardening process of the seats, and of all the cracked heads I've heard about, I've heard very few actually leaking water.

best budget springs for them are hughes #1110 springs, they'll allow about .540" of lift before you run into installed height problems...

Posted By: cudadoug

Re: school me on magnum heads - 12/12/12 09:48 PM

yup, hughes "iron ram" heads are enginequest 318A and 318B heads (magnum and LA intake pattern)....both use magnum pedestal mount rockers.

Oh yea, that's the other thing I don't like: I wish my EQ's could use LA rocker gear. Every time I see a great deal on LA roller rockers in the ads, it FRUSTRATES me "a little"...LOL!

Posted By: patrick

Re: school me on magnum heads - 12/13/12 03:57 PM

Quote:

yup, hughes "iron ram" heads are enginequest 318A and 318B heads (magnum and LA intake pattern)....both use magnum pedestal mount rockers.

Oh yea, that's the other thing I don't like: I wish my EQ's could use LA rocker gear. Every time I see a great deal on LA roller rockers in the ads, it FRUSTRATES me "a little"...LOL!

why? pedestal/stud mount rockers are much cheaper, and on a low buck build, having a factory 1.6 ratio is nice, especially since most OEM LA rockers measure closer to a 1.4 ratio

Posted By: moparacer

Re: school me on magnum heads - 12/13/12 04:00 PM

Quote:

Quote:

yup, hughes "iron ram" heads are enginequest 318A and 318B heads (magnum and LA intake pattern)....both use magnum pedestal mount rockers.

Oh yea, that's the other thing I don't like: I wish my EQ's could use LA rocker gear. Every time I see a great deal on LA roller rockers in the ads, it FRUSTRATES me "a little"...LOL!

why? pedestal/stud mount rockers are much cheaper, and on a low buck build, having a factory 1.6 ratio is nice, especially since most OEM LA rockers measure closer to a 1.4 ratio

Yep 1.6 chevy full roller rockers can be had for $100 a set...

I splurged and bought $200 harland sharps for mine lol.

Posted By: cudadoug

Re: school me on magnum heads - 12/13/12 05:21 PM

Quote:

Quote:

Quote:

yup, hughes "iron ram" heads are enginequest 318A and 318B heads (magnum and LA intake pattern)....both use magnum pedestal mount rockers.

Oh yea, that's the other thing I don't like: I wish my EQ's could use LA rocker gear. Every time I see a great deal on LA roller rockers in the ads, it FRUSTRATES me "a little"...LOL!

why? pedestal/stud mount rockers are much cheaper, and on a low buck build, having a factory 1.6 ratio is nice, especially since most OEM LA rockers measure closer to a 1.4 ratio

Yep 1.6 chevy full roller rockers can be had for $100 a set...

I splurged and bought $200 harland sharps for mine lol.

Oh I know. I'm headed towards the Chevy stuff. Sharp and Hughes Magnum rockers, although nice ARE a little spendy. I just prefer the LA shaft deal. Creature of habit I guess...

Posted By: Duner

Re: school me on magnum heads - 12/13/12 05:29 PM

I'm no porting expert - but my EQ heads with 2.02 option and some home-brewed bowl blending work gained me 3 tenths over my Mopar Performance heads.

I know all flow benches are different, but they ended up just a hair under 290 CFM on the intakes at .550 lift. We didn't bother measuring any higher because that's all the cam I'm running anyway.

Posted By: Crizila

Re: school me on magnum heads - 12/14/12 01:43 AM

Quote:

I'm no porting expert - but my EQ heads with 2.02 option and some home-brewed bowl blending work gained me 3 tenths over my Mopar Performance heads.

I know all flow benches are different, but they ended up just a hair under 290 CFM on the intakes at .550 lift. We didn't bother measuring any higher because that's all the cam I'm running anyway.

My Hughes "iron rams" home ported.

Attached picture 7502307-portedironram.jpg