SDRA Dragster For The Coast Build Thread

[P-Dog]

Lumps?

You'll find lumps on women also on the floor of 6 cylinder Cheby intake ports to enhance the flow, so I've been told.

P-Dog,,,,, doing my best to keep it clean........

[old sparks]

Thanks for the info on part two. I think I remember part one of your message.

[Old28]

P-Dog -- I an't going there.

[bobw]

Go to Skip Pipes' Team Seagull build thread here on the HA/GR forum. The last post has pics of the "lumps" and part of the modifications necessary to install them.

[Old28]

bobw --Ya Bob, I have talked to Skip at length about doing this and at this time I think phase-1 is all I can afford (mill head .060, have the machine shop cut the guides for seals, install the Z28 springs and 1.94/1.60 SBC valves). When I build the bigger motor I will have the other work done.

Should have a replacement cam & lifters at the house end of next week. If I do the head (got to check cash flow) may be a couple weeks before it is back together.

[ThingyM]

Tom.. If your talking about the 194 head. It already has the heavier springs installed.

[mudflap261]

how much money are we talkin about to add lump ports parts and labor.

[Old28]

ThingyM -- Dick, I did not know that, what is the max lift or what type are they. The card from Clay Smith shows max lift at 535 with 1.7 rockers like we are running. Also was the seat pressure set at 125/130 #'s as per the cam card?

I talked to Georges daughter Sherry today and they were just leaving for the weekend. She is going to put me together a deal on replacement cam & lifters and call me Monday, real nice people.

Would be nice if I don't need to change springs. Racers Outlet on Ebay sells a package with valves and springs for $135 and the valves by their self for $76. Pretty good deal (free shipping/no tax).

How did you get time off from your nursing duty's to post on the HAMB?
Tell the wife we are thinking about her.

[Old28]

mudflap261 -- Larry I can only talk for the Bakersfield area and there is only one shop that will take on the project ($450-500). May be more places in LA area with better price, but most shops don't want to take on the machine work on a single job basis. Skip Pipes has a real good machine shop in his area, don't know what they charge.

[ThingyM]

Tom. If I'm not mistaken, they are 128#... Max lift with the 1.7 was 550 ..

[bobw]

http://www.youtube.com/watch?v=8UC-jqHDsLk

Here's a video on installing lump ports. All you need is a machinist friend with a vertical mill. Might even get by with a good drill press.

[Old28]

ThingyM -- Dick, thanks for the information. Those numbers are the same as the Chevy Z28 springs. In our talks I never asked you if the stock springs had been changed. Knowing that the springs are correct for the cam I am not going to spend the money on more head work at this time and just install the replacement cam/lifters and drop the head back on.

You "Big Inch" SDRA guys are going to force me into building a 292 motor just to be a player.

bobw -- Bob, I have looked at that video 3 or 4 times, If I had a mill or a real good (old) drill press that could be slowed down a bunch I would try doing it myself. The other thing is that you need a good compressor to run one of those high speed grinders, I use the same little one I take to the track to air the tires and it can't keep up. I wish I had a machinist friend with a mill, but no such luck.

[mudflap261]

lumports how much of power increase can you expect. the gmcs /early chevs /slant 6 do not have lumpports is this a advantage for the later chevy.the idea of the class is affordabiltily. do we ban these lummpyports.do to cost or what comments

[P-Dog]

I don't see the cost being a factor, I think the "lumps" kit is about $135 (?) and can be installed at home by hand if a guy wants to put in the effort.
Of course some engined are going to have an advantage over others, we can't go around banning everything that runs well or can run will with the right parts and a good set up.
I say let the guys run lumps if they want, they are available to everyone and cost less than a good pair of tires.

No, I don't have a Chevy 6, just my opinion.

P-Dog.......

[Old28]

mudflap261 -- Larry, most of the stuff I have read on lumb ports is that they will help most all 194/230/250/292 heads that have the head bolt boss in the Intake passage, but were you see a big advantage is when they are coupled to bigger valves, better intakes, better exhaust and cams that make most of there power mid track on above 6200 RPM. They are not a one thing does it all fix. The Lumps them selves only run $80 or less, but the machine work to install them is high and if you are going to do them in your garage (shop) you better have some good equipment.
It is easy to get into a water passage if your not being careful.

I will do a lot with my valve train, cam/lifters/springs, fabricated intake and carb setup and real good headers before I would install lumps in this motor. Just my opinion. Others may do different, that,s their choice.

Just remember that after spending all that cash and time you still got to get it hooked to the track on those 6" tires & rims.


P-Dog -- I talked to a few guys that have done some at home and most said if they had it to do over again they would have Machine shop do it or look up a friend with a good mill. I know my limitations and this is one. Also it looks a lot easier on the video when the guy (Tom L) has done more than a few and is talking. If you can do it at home, go for it.

[bobw]

I have read about a few guys that have removed the head bolt boss and spot faced the floor of the port so the short head bolt will seat properly. And not installing the lump. Have not seen results of this modification. My guess is it isn't very effective as the siamesed intake port is large anyway. Might be a good deal with a blower.

In the Santucci book there's a chart that indicates a 32 cfm increase in air flow with the lump, in a competition prepared head.

Stock 1.72 Intake Valve 169cfm
Sissell Street//Strip 1.94 Intake Valve 206cfm
Competition-Early 1.94 Intake Valve Non-Lump 217cfm
Competition-Early 1.94 Intake Valve W/Lump 249cfm

The chart continues with New Design-Post 1985, where a big jump in cfm is noted. But, I believe it has to do with radical camshaft changes that make use of the siamesed port to better serve a single (currently firing) cylinder. Now, to find someone who grinds those secret cams.

Tom, I posted the Youtube Lump Port Video because other folks were curious. I figured you had done your due diligence regarding head work. If I'm using your build thread improperly just let me know.

Seems like your build thread is the place lots of guys are visiting so a good place to knock ideas and experiences around. All that is missing the the pretzels and beer (or Diet Pepsi).

[P-Dog]

Old28,

Please allow me to qualify my "do it at home" statement.

I am a stubborn old retired machinist who just loves the challenge of doing things at home with minimal equipment. I do have a reasonably good drill press that will handle some light milling and a small horizontal mill that comes in handy for some small odd jobs. I am making a set of aluminum main caps for a Volvo 4 banger at this time and just finished adapting an early hemi Hilborn injector to the Volvo head.

Sure, it would be much easier to take a head to a well equipped machine shop and pick it up a few days later but for me it's in the pride in over coming the difficulties of doing things at home that would be done much easier in a real shop.
Unfortunately, with all my machining background and measuring tools, I do know what is straight, square and right which only adds to the difficultly in making things just right basically by hand.

To each his or her own, for me it's the trip not the destination,
P-Dog.....

[mudflap261]

TOM /P DOG/BOB we do not want any more rules than absolutly necessary. THE 6 inch street tire rule works. But when guys get to talking about makeing HP there eyes glaze over and they see thereselfs smokeing off old soandso all thoughts of 6 inch tire disappear until later. I will check with our guys see what they think

[P-Dog]

mudflap261,

I'm with you, too many rules ruin the fun and innovation.
Personally I LOVE the 6" tire rule, it's the best I've seen in many a year!

P-Dog......

[Old28]

bobw -- Bob, no problem, it's all good information. There is little movement on most of the threads, so we will use mine for some amusement. I have talked to Mike Kerby (sissell) about the sportman port with no lump, it works well just removing that "broom size chunk" from the port. I still think lump port is not needed unless your going to run 7000+ RPM and 700-800 lift cams, but what do I know.

P-Dog -- I have not even seen your home shop and I know it has all the good stuff that an "old machinist" would have plus some. As I said in my opening when I started this build thread, I am more about being in the seat and making passes. I have already run what I conceder fast (7.02 @ 197) and now I just want to run 11.00-13.00 and have fun doing it. I just like this type of car (HAMBster's).

Mudflap261 -- Larry, the rules are fine, the 6" tire takes care of any advantage, there are a lot of other ways to make HP other than lump ports. Don't make more of them than they are, just another component to making HP. No one would even think about them if Chevy did not put this chunk of metal in the port to mess things up.