Here We Go: My 383 Stroker Winter Project

[joewithaboat]

Re: Here We Go: My 383 Stroker Winter Project

One of these

http://www.summitracing.com/search/...-Stud-Removal-Tools/?keyword=3/8+rocker+studs

pg 48 of this ARP catalog, you can keep your rockers

http://issuu.com/arpbolts/docs/cata...issuu.com/v/light/layout.xml&showFlipBtn=true

 

[John_S]

Re: Here We Go: My 383 Stroker Winter Project

If I were to do it, would revove heads from block and all of valvetrain from heads. Clean out the cutting oil/chips, followed by brake cleaner and compressed air. Reassemble.

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

So what are the odds that the pinned studs will pull out? And what kind / how much damage will occur if they do? This seems like its going to be lots of $ and work. If it's necessary I'll do it but I'd like to know what the odds are and how much $ it will cost me later if something goes wrong.

 

[joewithaboat]

Re: Here We Go: My 383 Stroker Winter Project

Are they pinned ?
If so they wont come out, Might break but wont pull. Your machinist pinned them?

 

[John_S]

Re: Here We Go: My 383 Stroker Winter Project

Agreed. If they were pinned you are good to go on the studs. Stock vortec heads just have pressed in studs, and no pins. Still might have to deal with the pushrod clearance.

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

My mistake, I thought pinned and pressed were the same thing. I just looked up pinned rocker studs on Google, and then went outside to check, and I definitely don't have pinned studs. They're just pressed. I don't want the studs to come out while I'm on the water, nor do I want to have to deal with it after the engine is in the boat, so I guess I'll go with the threaded ones. I'd rather not have the heads machined, so I assume I need studs that don't have the hex pattern on them? Can I get by with the hex pattern without having the heads machined?

Joe, you mentioned page 48 of the ARP catalog. Which part # studs were you referring to? They seem to all have the hex pattern.

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

Also I just went outside and put a strait edge across the stud bosses - they are exactly even. If there is any difference in height between them, is not noticeable to the eye.

 

[Tail_Gunner]

Re: Here We Go: My 383 Stroker Winter Project

You need to put in screw in studs with that much lift do not mess around with pinned anything. APR makes the studs about 10 a[peice and your machinst should tap in the threads...dont want a misalignment. Question if i may what springs are you using and what has been done to those heads so far..... In order to run a 1.6 rocker or lift over .470 the heads need work...differnt springs and probably retainers..... and your cam what is it....if it is a comp XM series you absolutely need screw in studs....THe lobes on XM ramp very quickley and boat engines are heavy duty cycle motors..far more so than a truck or car.

One big performance gain you are missing is not polishing your heads...Or better said smoothing out the cast imperfectons. Notice i left out grinding DO NOT do that Votec heads were very well done...and with your improved induction polishing could bring another 40-50 hp with a little sweat equity


http://www.summitracing.com/parts/ARP-100-7201/.......Those are the studs.....should be check appliations for the 350

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

You need to put in screw in studs with that much lift do not mess around with pinned anything. APR makes the studs about 10 a[peice and your machinst should tap in the threads...dont want a misalignment. Question if i may what springs are you using and what has been done to those heads so far..... In order to run a 1.6 rocker or lift over .470 the heads need work...differnt springs and probably retainers..... and your cam what is it....if it is a comp XM series you absolutely need screw in studs....THe lobes on XM ramp very quickley and boat engines are heavy duty cycle motors..far more so than a truck or car.

One big performance gain you are missing is not polishing your heads...Or better said smoothing out the cast imperfectons. Notice i left out grinding DO NOT do that Votec heads were very well done...and with your improved induction polishing could bring another 40-50 hp with a little sweat equity


http://www.summitracing.com/parts/ARP-100-7201/.......Those are the studs.....should be check appliations for the 350

I'll call my machinist tomorrow and ask him how much it would cost to have the heads tapped for the screw-in studs. Hopefully he can do it quickly and cheap, although I'm betting he is going to say I don't need them. The cam I am using is XM-270HR. Lift is .495/.503, and the 1.6 rockers increases the lift to .528/.536. The springs are Manley 22410, 345 lbs./in spring rate.

I actually talked to one of those online "experts" from summit racing an hour or so ago, before I read your post, and he told me to use a different ARP stud - part # ARP-134-7104. It seems to be longer and have a different base thread pattern.

Can I polish the heads myself?

 

[Tail_Gunner]

Re: Here We Go: My 383 Stroker Winter Project

Nice cam excellent selection...4 degrees of overlap at 50...Your close to reversion but it should work...Now that is a opinion.....Yes you can polish your own heads...Hmmm seems sanding is never ending when it comes to boats..Here a vid look at his heads see how shiny they are that is what you are looking for. I have a good guide some place but for now heres a vid you should get a kick out of. By the way that grumpys garage link will give you every peice of info you could ever find.

http://www.youtube.com/watch?v=sZDlZxqRVJw&feature=related


Could be on the apr studs...But you absolutey need them do not let you machinst say no


http://www.youtube.com/watch?v=3FRodBDKOAo&feature=related Get er done...

 

[John_S]

Re: Here We Go: My 383 Stroker Winter Project

Read up on polishing heads and see if the work is worth doing for the max rpm range you will be running and planned exhaust. If you are going to get the grinder/polisher out, look at match porting the intake to the heads. If it was me, I'd leave the grinder/polisher on the shelf.

 

[RogersJetboat454]

Re: Here We Go: My 383 Stroker Winter Project

I would be gasket matching, and conservatively cleaning any obvious casting flash out of the intake ports of the heads. IMHO, you are not going to gain a huge amount spending hours to polish the ports on a low RPM engine. I'm of the school of thought that a bit of a rough surface promotes some turbulence that helps to mix the fuel and air entering the engine. On top of it all, getting a bit too aggressive with a grinder and removing too much material can hinder performance rather than help.

 

[joewithaboat]

Re: Here We Go: My 383 Stroker Winter Project

Air flow is a tricky thing, very much a science. Ive seen many botched porting/ gasket match jobs come into the shop i worked at. While i agree that improvements can be great, a vortec is already pretty good as is. Id let it be. I have a set of fully worked iron heads (041 castings,non vortec) that i did myself (flow bench) and i will never do another, its a long process.

As to the stud, I would call ARP and ask if they have a non hex base stud specifically for vortec castings. I bet most people use the hex base and guide plates (drill out the pushrod hole) that way you can keep from buying the more expensive self aligning rockers. Remember you have poly locks that fit the factory vortec thread right now, so you need a stud that is the correct height, same top thread if possible, correct bottom length/dia/thread pitch. ARP is a very good brand, its been years sense i called them but they were pretty smart back then. They did their own R&D work, I bet they still do.

Its good you don't have pinned studs, i my opinion it ruins a set of heads. Weakens the casting and they cant ever be converted to screw in.

Be patient, do your homework, don't get bummed out by set backs, its part of the process.

 

[John_S]

Re: Here We Go: My 383 Stroker Winter Project

I think he already has self-aligners, so you don't want to run them with guide plates (binding). and is not running the rpms that he should swap back and go to guide plates. Would need hardened push-rods for that, as well. I believe the pushrod holes gets opened with a 1/2" drill for the 1.6 ratio rockers.

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

I think he already has self-aligners, so you don't want to run them with guide plates (binding). and is not running the rpms that he should swap back and go to guide plates. Would need hardened push-rods for that, as well. I believe the pushrod holes gets opened with a 1/2" drill for the 1.6 ratio rockers.

I do already have self aligning rockers. I spoke with a tech at summit racing today and he told me that I can use hex base studs without machining the bosses. I took a good look at them and laid a strait edge over them and they are all almost the exact same height anyways. He gave me a part # for ARP studs, 1.75 inches long and $42.65 for a set of 16. I'll probably buy those along with the tool to tap the holes myself.

I have to say I'm a little uneasy about taking a grinder or polisher to the heads I just spent a lot of $ reconditioning. I've never done it before. I think the idea of removing the obvious casting flash/imperfections from the ports is a good one but I'm afraid to do anything more without the help of a professional.

 

[joewithaboat]

Re: Here We Go: My 383 Stroker Winter Project

I think he already has self-aligners, so you don't want to run them with guide plates (binding). and is not running the rpms that he should swap back and go to guide plates. Would need hardened push-rods for that, as well. I believe the pushrod holes gets opened with a 1/2" drill for the 1.6 ratio rockers.

I was guessing that he did have the self aligners already, I was providing a possible reason why studs without shoulders may not be common. I think all custom pushrods are hardened anyway.

If you are going to port you own heads you definitely need to get a book written by someone who has a flow bench and is talking specifically about the casting you are porting. There are obvious things to do but you can hurt as much as help if your not careful. The short side radius is where most of the damage is done by inexperienced porters. Ive seen lots of folks find the water jacket in the intake ports... That's something you don't want to do.

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

If you are going to port you own heads you definitely need to get a book written by someone who has a flow bench and is talking specifically about the casting you are porting. There are obvious things to do but you can hurt as much as help if your not careful. The short side radius is where most of the damage is done by inexperienced porters. Ive seen lots of folks find the water jacket in the intake ports... That's something you don't want to do.

I'm definitely afraid of screwing up grinding away at these heads. I'll read up on it this week and if I don't feel comfortable with it, I'll just leave it alone or get a quote from my machine shop to do it.

As for those rocker studs - the guy from summit said I can buy the hex base studs without machining the bosses. He said if I wanted guide plates then I would need to machine them but since I have self-aligning rockers I'll be fine without machining them. Do you guys know if this is correct?

Also, John you mentioned a 1/2" drill for the push rod holes. Does this just mean that I can just take a half inch drill bit and widen the holes? Is that all it takes? I can't imagine I'd be doing any damage to the heads just by slightly widening the holes...

 

[Tail_Gunner]

Re: Here We Go: My 383 Stroker Winter Project

I think he already has self-aligners, so you don't want to run them with guide plates (binding). and is not running the rpms that he should swap back and go to guide plates. Would need hardened push-rods for that, as well. I believe the pushrod holes gets opened with a 1/2" drill for the 1.6 ratio rockers.

I agree with john here on both points....First your valve geomtry has changed and with out a doubt you will need to tap you rod holes to 1/2
" let the machinst do that and hardened rods are also in order..... XM cam lobes are very abrupt ...they lift the valves @ extreme lift rates and under heavy loads..By the way the tech was right..a dual pattern cam will scavenge the exhasut port far better than a single....At the cost of potential reversion and that can be easliy over cone

Polishing the heads yes it will add gains and under 5000 rpm

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

I agree with john here on both points....First your valve geomtry has changed and with out a doubt you will need to tap you rod holes to 1/2
" let the machinst do that and hardened rods are also in order..... XM cam lobes are very abrupt ...they lift the valves @ extreme lift rates and under heavy loads..By the way the tech was right..a dual pattern cam will scavenge the exhasut port far better than a single....At the cost of potential reversion and that can be easliy over cone

Polishing the heads yes it will add gains and under 5000 rpm

I'm going to call the machinist tomorrow and ask him how much he would charge to port and polish the heads. I'm already pretty far over my supposed "budget" for this project. I'm confused as to why I can't just widen the push rod holes myself with my drill press or a hand drill.. Why does the machine shop need to do that?

 

[joewithaboat]

Re: Here We Go: My 383 Stroker Winter Project

I'm going to call the machinist tomorrow and ask him how much he would charge to port and polish the heads. I'm already pretty far over my supposed "budget" for this project. I'm confused as to why I can't just widen the push rod holes myself with my drill press or a hand drill.. Why does the machine shop need to do that?

You can widen the holes yourself, just be sure to follow the push-rod angle when drilling not parallel to the stud.
You don't need to "port and polish" the head. I would not let your machinist do that anyway. If he doesn't have a flow bench in use, not pushed over in the corner with stuff piled up on it, that he uses regularly you don't need him to do that anyway. I think You should stick to your original goal as far as horse power and money. Spending money professionally porting iron heads is thought of by most who do it professionally to be a waste of money. The heads you have as cast should make 400 hp. If you want to spend more money sell those and buy better aluminum ones.

You can make easy gains, maybe 10 to 20 hp in upper rpm's by doing simple things like ...
blending the bowls
contour and smoothing the guide boss
unshrouding the valves
gasket match
smoothing the short side radius

You could also kill air velocity and loose 20 or more hp down low if you don't know what you are doing.

In a nut shell you need threaded studs you don't need to port those heads, that's just my opinion anyway.