Building a 383 Stroker

[joewithaboat]

Re: Building a 383 Stroker

You need oil on mains to get proper tq. Lock-tite good for others you listed. That blue is cool but $$ i always use black.

 

[wca_tim]

Re: Building a 383 Stroker

my understanding is that you want your ring end gaps a couple thousandths bigger than for a "regular" car engine and you want an extra thousandth or two in main and rod bearing clearance (to offset the extra heat build up, I was also advised to run a thermostatted oil cooler and do). Run a standard volume oil pump (so you don't pump all the oil up into the heads, run low in the pan and cavitate the pump at high rpm) and also a large volume baffled oil pan. again, jkust some of the things that were suggested and I do. I do however run mine for fairly long periods of time at 5500+ rpms... and have had it at 6,000 rpms more than a couple times.. I also have a forged steel crank, forged H-beam rods, comp roller rockers, hardened push rods, arp bolts throughout, all arp fasteners, 7 qrt oil pan, block was blueprinted / reference bored, etc, etc..

The intake probably won't make a lot of difference and is something you can swap out later if you're thinking you want more. Weind stealth is also a great intake...

Know you have the heads, but I think the single bast decisions I made was to buy the competition cnc ported afr 195s. HUGE power increase... I'm running a hydraulic flat tappet cam... to be honest, after playing with my corvette engine (thinking cams...), I'm really tempted to do a cam upgrade on the boat this winter...

I've run edelbrock 750 and wound up liking the Holley 750 double pumper (4150 series). Proform body, quick fuel base, couple mods here and there. once I got the jets and air bleeds right it does well on fuel and has great throttle response and power throughout the rpm range.

If you're assembling it how is the machinist doing the work to be sure the rod bolts don't hit anywhere and that it's well balanced?

btw. I painted all the engine parts with dupont nason single stage urethane over etch primer... I went with fireball red metallic for most of the engine parts. the aluminum engine parts (ie exhaust manifolds, tall valve covers) were polished and then painted with por-15 glisten clear. Still holding up great after 2-3 years of abuse. If you really want merc racing blue, I'm sure one of us can dig up the dupont or ppg paint code for it. I have it saved somewhere, others probably do as well.

Hope you're having fun with it! Looking forward to seeing how it comes together for you

 

[joewithaboat]

Re: Building a 383 Stroker

my understanding is that you want your ring end gaps a couple thousandths bigger than for a "regular" car engine and you want an extra thousandth or two in main and rod bearing clearance (to offset the extra heat build up, I was also advised to run a thermostatted oil cooler and do). Run a standard volume oil pump (so you don't pump all the oil up into the heads, run low in the pan and cavitate the pump at high rpm) and also a large volume baffled oil pan. again, jkust some of the things that were suggested and I do. I do however run mine for fairly long periods of time at 5500+ rpms... and have had it at 6,000 rpms more than a couple times.. I also have a forged steel crank, forged H-beam rods, comp roller rockers, hardened push rods, arp bolts throughout, all arp fasteners, 7 qrt oil pan, block was blueprinted / reference bored, etc, etc..

The intake probably won't make a lot of difference and is something you can swap out later if you're thinking you want more. Weind stealth is also a great intake...

Know you have the heads, but I think the single bast decisions I made was to buy the competition cnc ported afr 195s. HUGE power increase... I'm running a hydraulic flat tappet cam... to be honest, after playing with my corvette engine (thinking cams...), I'm really tempted to do a cam upgrade on the boat this winter...

I've run edelbrock 750 and wound up liking the Holley 750 double pumper (4150 series). Proform body, quick fuel base, couple mods here and there. once I got the jets and air bleeds right it does well on fuel and has great throttle response and power throughout the rpm range.

If you're assembling it how is the machinist doing the work to be sure the rod bolts don't hit anywhere and that it's well balanced?

btw. I painted all the engine parts with dupont nason single stage urethane over etch primer... I went with fireball red metallic for most of the engine parts. the aluminum engine parts (ie exhaust manifolds, tall valve covers) were polished and then painted with por-15 glisten clear. Still holding up great after 2-3 years of abuse. If you really want merc racing blue, I'm sure one of us can dig up the dupont or ppg paint code for it. I have it saved somewhere, others probably do as well.

Hope you're having fun with it! Looking forward to seeing how it comes together for you

Great info..... Thanks for sharing!
I was wondering about bearing & ring clearances. I a heard folks say different things in regards to this. Its always nice to hear from someone who is actually doing it. Do you know specifics on the clearances. Was it a "thousandth or two" above "stock" or above general performance type spec? Ive even heard that some folks add clearance to or machine the piston a little different for running flat out on the water for extended periods. Again always nice to hear from someone who is actually doing it. We have the proof from your vids
I have a tricked out holley for a drag racing small block... amazing difference from out of the box Holley! Does Proform make a marine Jtubed body or did you switch them?
Thanks again

 

[wca_tim]

Re: Building a 383 Stroker

To be perfectly honest, I'm not certain about the exact tolerance differences to use. After talking with a lot of people and finding the engine builder that did the work, I just let him and his crew do their magic with the machine work and bottom end assembly on this one. The fellow is a local legend that has made a living for many years building "bulletproof" engines for offshore racing boats and for the circle track crowd. He'd run all sorts of combos on the dyno including different wet exhausts, heads, intakes, bottom ends, etc... various engine configurations he put together with "off the shelf" parts with various engine combos, etc, etc, etc... I understand that he did that for a local performance boat builder that was considering going with their own line of performance engines.

To be frank: I'm not the expert! Just have been paying attention to what I'm told, doing my own homework, learned a lot through trial and error (I break lots of things along the way...) and have been lucky enough to find lots of folks in the area here with a world of relevant experience. It probably hasn't hurt that I have a little engineering background, work as a scientist, and went to machinist school more out of curiosity and so I could do more of my own "playing". OBviously a number of folks on here have various backgrounds, experience and skill sets that are on point.

Regarding j-tubes. I just made my own out of some tubing...

 

[greg82255]

Re: Building a 383 Stroker

The machine shop said that they were going to build in the oil clearances as part of the crank cost. They told me they were going to give me a chart with all my bearing clearances and that I wouldn't even need the plastic gauge to check them (although he said he would give me some if I want it). They also took my flywheel so they could mill the weight off and internally balance the rotating assembly. I'm not exactly sure how they are doing it but I was told it would be internally balanced. He also told me the rings are file-fit, so I guess I will be making those clearances myself.
As for the rod/block clearances, this machine shop has built several 383 stroker engines and said they know exactly how to clearance the block/rod bolts/whatever else needs to be done. The larger oil pan/cooler is also something to think about. If I don't plan on running for more than 3 or 4 minutes at WOT at any given time, is it really necessary? Don't know if it matters, but I am also running brand new ARP bolts throughout.

To be frank: I'm not the expert! Just have been paying attention to what I'm told, doing my own homework, learned a lot through trial and error (I break lots of things along the way...) and have been lucky enough to find lots of folks in the area here with a world of relevant experience. It probably hasn't hurt that I have a little engineering background, work as a scientist, and went to machinist school more out of curiosity and so I could do more of my own "playing". OBviously a number of folks on here have various backgrounds, experience and skill sets that are on point.

Tim, I am doing exactly what you did. I'm paying attention to everything I am told and listening to the expert opinions that I am given (and since you have a running 383 and know how it was built, I consider you one of the experts!). I actually have an engineering background as well (well, I just graduated from engineering school and am currently doing a Master's in Mechanical Engineering - I'm only 22) so hopefully that helps a little. I'd love to go to machinist school just out of curiosity, maybe a few years down the line.

If someone has the Dupont code for that Mercury racing blue paint and posts it, I would be very grateful... Also, I'm supposedly getting my block and heads back next Friday, so I'll post some pictures once I do.

 

[greg82255]

Re: Building a 383 Stroker

I actually found the Dupont paint code. Dupont B8110A. Now the question is how to get hold of some?

 

[joewithaboat]

Re: Building a 383 Stroker

I actually found the Dupont paint code. Dupont B8110A. Now the question is how to get hold of some?

any local autobody supply or try here http://www.tcpglobal.com/Restorationshop/

 

[wca_tim]

Re: Building a 383 Stroker

I usually buy dupont nason line at napa for engine paint. shoot their etch primer (not the rattle can kind), and then two medium coats of single stage urethane. it holds up great. a lot better than rattle cans, and there's no comparison in terms of glass and durability.

Sounds like your machinist know's his stuff. There are lots of good ones around and a 383 is a trivial thing for most any more.

You're probably fine with stock type oil filter, pan and no cooler. could always buy a cheap temp guage and mount it in in the plugged port over the oil filter and see what your oil temp is during a hard run. I also ran with one in the drive lube in an upper for a while...

I also take the oil pressure off the front of the engine, downsteam of teh bearings. gives a lot better idea of how thin the oil is. don't do it this way iof it bothers you to see your oil pressure guage move around though.

Any luck finding exhaust?

oh, and GREAT on school! Keep with it as long as you can and do as well as you can. It'll pay off in the long run... big time

BTW. if you're going to do the engine compartment while you have it out. imron works great put on with a brush or roller and is safe to wear just a combination charcoal respirator as long as you're not spraying. wear a respirator for the nason, it'll mess your lungs up if you don't...

 

[greg82255]

Re: Building a 383 Stroker

So you are saying if I go to a napa store they will be able to mix the paint for me? My machinist does seem to know his stuff. He makes most of his money building race engines for cars and trucks and says he has built several marine 383s before also.

I've been thinking about adding an oil temp gauge. My uncle has one on his Fountain with a 500 EFI, but I figured with a stock merc 260 there was no need. I think it would make sense to have one on this motor. Where would I mount the oil pressure gauge if I wanted to take pressure from the front of the motor?

No luck finding an exhaust yet. If I see a good deal sometime in the next few months then I'll definitely grab it, but otherwise I'll probably stick with the stock manifolds and buy some aftermarket risers that flow better. I've seen a few that claim they will add 10 horsepower when bolted onto the stock manifold.

I'd like to do the bilge while the motor is out. It's such a pain to clean though. I spent the better part of 4 hours trying to clean all the crap out of the engine compartment and didn't make much progress. It also seems like to do it right you really need to take all the stuff out of there (Trim pump, blowers, bilge pump, etc.) I may just do the section under the engine because that paint has come off and it's basically just bare fiberglass. Here's what it looks like.
View attachment 119501

 

[greg82255]

Re: Building a 383 Stroker

Spoke to the machinist again today, this time about a cam because we already have the heads worked out. He said that if I want to go roller he recommends Comp Cams Xtreme Marine, .495/.503 max lift, 218/224 duration @.050, 112 degree LSA. If I want to go flat tappet he said we should go with XM-270H (.480/.489, 226/236 @.050, 112 LSA) - the same one that wca_tim recommended. So now the question is, how much benefit am I going to get with the roller over the flat tappet? How much HP/torque will I gain with the extra lift, and how much better will the idle be with the rollers? Looks like its going to be in the $800-1000 range for the roller vs about 300 for the flat tappet kit.

 

[Tail_Gunner]

Re: Building a 383 Stroker

Roller cam should give improved throttle response if you upgrade the springs actuallly the whole valve train..But long term reliability would be a key factor....Do you plan on doing a light polishing on the heads..

 

[greg82255]

Re: Building a 383 Stroker

I caved and bought the retro-fit roller. 900 bucks out the window. What do you mean by a light polishing - what part of the heads gets polished? I'm not familiar with that concept. I just had them fully reconditioned/machined -baked and blasted, 3-angle valve job, stainless valves, new comp cams spring kit w/retainers and keepers, and they machined them to make sure they are flat.

 

[Tail_Gunner]

Re: Building a 383 Stroker

Just read the thread...your machinst is very good. Light polish is simply removing factory cast imperfections and polishing the surface but your head are beyond that now...Have you asked your machinst why not a 1.6 lift on the rockers especially the exhaust side

Heres is some of the best head info on the net.... http://www.nastyz28.com/forum/showthread.php?t=56505

And Grumpy's Garage..

http://forum.grumpysperformance.com/viewforum.php?f=52

Heres a example for your cam question http://forum.grumpysperformance.com/viewtopic.php?f=52&t=3802


Heads polishing.... http://forum.grumpysperformance.com/viewtopic.php?f=52&t=401

 

[greg82255]

Re: Building a 383 Stroker

Well, it's official. Basically everything has been decided. I'm going to list all the parts I am using so hopefully someone else will be to use it as a reference.

-Block baked and blasted, bored .030 and honed, line honed mains, decked block, clearanced for 383 (block and rods clearanced)
-Internally balanced rotating assembly (done by the machine shop, took my flywheel and milled the weight off of it and internally balanced)
-Speed Pro Hypereutectic pistons -23cc dish
-Forged 4340 I-beam 6" rods with ARP bolts
-Scat Cast Steel Crank 383 ci 3.75" stroke
-Mahle plasma moly rings
-Comp Cams Xtreme Marine .495/.503 max lift, duration 218/224@.050, 112 LSA
-Vortec Heads, 64cc (might be 62cc after the machining, not sure) reconditioned w/stainless valves, 3 angle valve job, comp-cams springs/retainers
-Summit Racing aluminum full roller rockers, 3/8" stud, 1.5 ratio
-ARP bolts throughout
-Melling oil pump
-Holley mechanical fuel pump
-All Fel-Pro gaskets and 1pc rear main seal (head gaskets w/a stainless core)
-Still deciding on an intake (either performer or RPM air gap) and a carb (holley 4150 most likely, something 750 CFM)
-Might run a crossover instead of a circulation pump, not sure yet
-Re-using pretty much everything else (balancer, flywheel, bell housing, timing cover, oil pan, alternator, motor mounts, pulleys, maybe t-stat housing and circ pump)

-Finishing it off with Mercury Racing Metallic blue (Dupont code B8110A)

Total cost was about 4k. I'm sure there will be some more odds and ends. Hopefully someone who is starting a 383 project like I was can use this thread for some helpful information. Thank you to everyone that was able to give me help as I picked out the parts.

If anyone sees something that I missed, or that I am reusing that I should replace, please let me know.

 

[greg82255]

Re: Building a 383 Stroker

Just read the thread...your machinst is very good. Light polish is simply removing factory cast imperfections and polishing the surface but your head are beyond that now...Have you asked your machinst why not a 1.6 lift on the rockers especially the exhaust side

Heres is some of the best head info on the net.... http://www.nastyz28.com/forum/showthread.php?t=56505

And Grumpy's Garage..

http://forum.grumpysperformance.com/viewforum.php?f=52

Heres a example for your cam question http://forum.grumpysperformance.com/viewtopic.php?f=52&t=3802

I agree he's very good - he seems to know his stuff and he has taken the time to give me a detailed answer for every one of my questions (and there have been a lot). I didn't ask about 1.6 rockers, although you are not the first to bring that up. I believe wca_tim brought that up as well. I'll call tomorrow and ask about it. I've never installed rockers before and it doesn't make sense to me that you can just bolt on a different ratio - it seems like the components wouldn't line up if you did. Do you need to make any other modifications to make the different ratio rockers work?

 

[Tail_Gunner]

Re: Building a 383 Stroker

Read the links all of your questions will be answered and probably a 1000 new questions for your machinist Grumpys place is extremely imformative

 

[greg82255]

Re: Building a 383 Stroker

The site does seem very informative. I'll keep sifting through it in case I have any other questions. Thanks for the help.

 

[joewithaboat]

Re: Building a 383 Stroker

As long as you are getting all new stuff you may as well go for 7/16 studs rather than 3/8 and the rockers to fit. If you have already got um you could add a stud girdle instead.

 

[John_S]

Re: Building a 383 Stroker

Assuming you are still doing the assembly, spend some time reading those articles on setting up the valve train. From decking the block, shaving the head, along with complete cam and valve train changes, probably means some geometry checks and push rod length measurements.

 

[greg82255]

Re: Building a 383 Stroker

Yea, my machinist said I was going to have to measure the push rod length. He said to assemble everything up to that point and then call him and he will guide me through the measuring. I'll read up, but just out of curiosity what other geometry checks are involved? I know the intake manifold will probably sit lower but I'm not sure what else.