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Discussion Starter #1
I know how everyone is about details so, the boat is a 19' miller jet, '' A '' impeller . the old engine was a 30 over BBC 427 , -50.cc dome , winters 074 heads . comp cams xm288h hyd flat cam. old school weiand rect port with sideways 750's. it would turn a solid 5100 rpm. this combo ran flawless for 7+ seasons as a river/ski boat. i was going to build the exact same engine again with maybe a similar roller cam. now I'm thinking maybe i should sell the 074's and use a set of Brodix RR 270cc or equivalent, but keep everything else about the same . lets here some opinions please....
 

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Those Brodix have seemed to do well.

I thought you where stroking this engine ? You have a tall deck 427 block right ?
 

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Discussion Starter #3 (Edited)
yes i do have a TD block but decided to use that for a different project ( hydro).the engine in this is just a std 9.8 4blt .this boat is just our family boat and runs good for what it is so i want to keep the engine about the same
 

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If you're concerned with keeping the stock ex port location, that's going to be about your only choice in an aftermarket alum. head. Regardless, they work well with the right cam. Be sure the get the CNC chamber option. If the ex isn't an issue, another choice would be the small oval AFR 265. It's a much better flowing head than the Brodix, even with Brodix' CNC chamber. The AFR ex ports are raised .375" from stock. AFR has a CNC chamber option but it kills a bit if the upper lift low in trade for some really strong 2,3 and 400" lift flow numbers. If you're going to run a cam in the .550" lift range, the CNC chamber would be the way to go. IMO, if you're going to run in the 600-650" range, the extra flow up there without the CNC chamber would be beneficial. Again, the CNC option on the Brodix is the only option I'd recommend as it's a significant improvement over the non CNC head.
 

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Discussion Starter #6
Awww...this was a deceiving thread title:D
;)...


I haven't decided on a cam yet, the AFR heads are very nice but a bit out of my budget for this , i figured by selling the winters heads i could pay for some bare brodix heads with little out of pocket $. now i have more questions,
should i keep the heads i have insted of the brodix? they are in great shape with no damage or repairs ( why i was thinking about selling them now before they get damaged,)
should i think about switching to oval ports to get the runner cc's down?
also just so I'm clear ,when you say ''raised exhaust ports" is just the port exit raised or the entire exhaust mounting flange surface.
 

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Hell, it is going in a jet boat. Just spray paint your cast iron heads silver. It will do the same thing. ROFL! :)grn
Wags
 

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steelcomp was here
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;)...


I haven't decided on a cam yet, the AFR heads are very nice but a bit out of my budget for this , i figured by selling the winters heads i could pay for some bare brodix heads with little out of pocket $. now i have more questions,
should i keep the heads i have insted of the brodix? they are in great shape with no damage or repairs ( why i was thinking about selling them now before they get damaged,)
should i think about switching to oval ports to get the runner cc's down?
also just so I'm clear ,when you say ''raised exhaust ports" is just the port exit raised or the entire exhaust mounting flange surface.
IMO the ovals would work a lot better in the rpm range you're running and the small c.i.. The AFR's and Brodix are priced about the same except for special deals.
Those Winters heads are popular for the traditionalist guys...you see a lot for sale that were ported by Brandywine, Jenkins, etc. and have been welded on, repaired, abused and so on. If you have a pair that are unhurt and still in good condition you might be able to get a decent price for them, but also understand that buying a set of bare heads isn't the cheapest/least expensive way to go. It might ensure that you get what you want as far as the quality of the parts you use to build them, but it will cost you more in the long run.
When they say the ex port is raised, that means the entire ex flange and bolt pattern is raised and can be a problem with some exhaust systems when switching heads. If you have headers it shoudn't matter. If your miller has logs and hoses it might mean new hoses.
Bottom line is, if you're happy with the way the boat runs, you could freshen up the engine and heads, get some flow numbers and do a roller cam upgrade. If you;re starting form scratch on a new engine, then you might consider a stroker and move the engine more into the operating range of the heads where the runners aren't as much of an issue. That old school Weiand and those heads are pretty cool and "period correct" in a Miller. ;)
 

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Trick Flow 280 ovals might fit the bill. Never used them before. Inexpensive at Summit/ATECH. Took delivery of a pair monday. 145lbs on the seat 385 at .520. Ferrea valves. Excellent gasket match to Felpro. Light core shift in the bowl. I left it alone. Dart 2pc guide plates are an absolute pain in the ass. +.190-.200 pushrods required w/Comp 224/230 shelf HROL and Comp lifters. 70 Chevelle SS convert 4 spd (clone) LS6 454+.100/ Perf RPM/ 9.7 comp ratio/ Dougs 1.875 headers. Hope to chassis dyno it late next week. Vintage air still to be finished and real rally type dash. 350-360 at the wheels? I will post findings if it helps with your choice. This would be about 430-440 crank on my dynojet.
 

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I also had an extra .035-.040 piston to valve clearence w/TFS over the correct LS6 semi-open-looking 108 cc chamber head. I noticed you had a big dome you might be re-using: if this info matters in cam selection. You could mock up what you have for PTVC now, it may guide you as to what you can expect with the TFS. Just a note. Obviously check any new cam/head combo.
 

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yes i do have a TD block but decided to use that for a different project ( hydro).the engine in this is just a std 9.8 4blt .this boat is just our family boat and runs good for what it is so i want to keep the engine about the same
Not that i know anything...cause i don't but it seems like the stoker deal is more suited to the jet and dogging a 3.76 down to 5100 is giving up what that short stroke does best...I have a ski hydro with a 427 roller/660's 11.5-1 closed chamber pump gas...5k is about where it starts to get happy....and i don't think it would work well at all in a jet....just my opinion...I will be swapping in a few different motors next month...ie jet boat motors with 4.25-4.50 stroke and 6600 red line.
 

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I have the Brodix 280cc rectangle BB1 on our .030 454.
Crane Gold rockers, Brodix girdles.
19' Miller with a stainless A. Droop and Place.

9.5:1, Comp Hyd. roller. .565, 302 advertised.
TR with 2 750's. Used to have 2 660's on it.
EX. ports are raised .6

Turns 5400-5600, 80 - 85 MPH on GPS.
 

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Discussion Starter #15
thank you all for the info, there is so many directions i can go with this but after thinking it over and talking with some people who defiantly know there stuff, i probably will be keeping the 074's and have someone go threw them , get some Flo #'s, get a cam based on that info and be happy . I'm sure i will be leaving some on the table, but for what it is it should run pretty good. then i can start tuning the pump and maybe cut the impeller and get the rpm's up a little and work more in that department.

Not that i know anything...cause i don't but it seems like the stoker deal is more suited to the jet and dogging a 3.76 down to 5100 is giving up what that short stroke does best...I have a ski hydro with a 427 roller/660's 11.5-1 closed chamber pump gas...5k is about where it starts to get happy....and i don't think it would work well at all in a jet....just my opinion...I will be swapping in a few different motors next month...ie jet boat motors with 4.25-4.50 stroke and 6600 red line.
not to get off the subject , but will your ski hydro blow the tail with your current setup?


Turns 5400-5600, 80 - 85 MPH on GPS.
thats about what i was shooting for, but i suspect i will have to cut the impeller to get there.
 

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FWIW Be cautious when buying bare heads from AFR. The reason I say that is ,I purchased a set of SBC 220 bare and not only did it take 3-4 months to get them but but when I removed them from the box I was absolutely taken back by what they shipped me . In short they pulled them out of the sand shook them off and sent them to me . They only machined the spring pockets , valve seats , rocker studs. Absolutely no port work whatsoever. Without exaggeration you could not but your thumb into the intake port. So I call them, "WTF!" I say, but only in a nicer way. And their response was "You ordered a bare set of castings and you got a set of bare castings. My response was 'No, I ordered a bare set of 220's not a bare set of 18's so no I did not get what I ordered. And after a short pause he said "I cant help you sir."

So with that being said ,order at your own risk.
 

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FWIW Be cautious when buying bare heads from AFR. The reason I say that is ,I purchased a set of SBC 220 bare and not only did it take 3-4 months to get them but but when I removed them from the box I was absolutely taken back by what they shipped me . In short they pulled them out of the sand shook them off and sent them to me . They only machined the spring pockets , valve seats , rocker studs. Absolutely no port work whatsoever. Without exaggeration you could not but your thumb into the intake port. So I call them, "WTF!" I say, but only in a nicer way. And their response was "You ordered a bare set of castings and you got a set of bare castings. My response was 'No, I ordered a bare set of 220's not a bare set of 18's so no I did not get what I ordered. And after a short pause he said "I cant help you sir."

So with that being said ,order at your own risk.
Wow, that's what I call a "bare casting"!

I ordered the Brodix through Summit, had them in a week, and they came port matched (to the Brodix gasket) and blended without even asking.
 
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