Null


Pages: [1]

joe morgan

  • Karma: +0/-0
1978 glastron/carlson cvx20
« on: June 27, 2012, 07:33:13 PM »
Im new to the world of jets but, I have a 78 cvx 20 with a 12je-a pump and a 460 ford engine. I have completely rebuilt the engine with all new parts.
the only thing that was reused was the stock d3ve heads the have been gasket matched and heavily ported on the exhaust side. The lower end has
been bored 30 with flat tops and arp main studs and rod bolts.  Im running 10.5 to 1 compression with a comp extreme marine 288h hydraulic cam
288 duration on intake with 580 lift and 304 duration with 585 lift on exhaust.  The intake is an offy port o sonic with a spacer.  The carb is a AED holley
850 mech secondaries with electric fuel pump. I have comp roller rockers installed on the heads with the egr ports completely cast closed and port
blended.  The 12je pump is stock with an a impeller and I have installed a SS loader, the pump does not have a place diverter installed.
dizzy is a USA accel mech. advance with msd blaster 2 coil. no box.
Lake/gps test read 58mph at 3900rpm!  that just seems a little low, both tach and mph.
Any info. ?
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

USCvictory

  • Karma: +4/-0
Re: 1978 glastron/carlson cvx20
« Reply #1 on: June 27, 2012, 08:05:38 PM »
Nice looking boat. Motor looks clean. What type of exhaust do you have?

Sent from my SPH-D710 using Tapatalk 2
Logged
  • Boat #1: 1976 MRED
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

raginaquaholic

  • Karma: +0/-0
Re: 1978 glastron/carlson cvx20
« Reply #2 on: June 27, 2012, 08:34:01 PM »
That is a real cool looking boat. How many GPH is your electric fuel pump putting out?
Logged
  • Boat #1: 1979 Nordic Day Cruiser
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

IRRebel

  • Karma: +16/-0
Re: 1978 glastron/carlson cvx20
« Reply #3 on: June 27, 2012, 10:50:28 PM »
More speed should be there! The @3900 RPM is what struck me. What's limiting that? Ignition? Timing? Valvesprings? FWIW, Main studs are a downgrade from bolts on the 460 Ford. Sometimes necessary for say a Dooley pan and it's windage tray, but for the most part, stay away from them. But that is not your problem.

I read a lot of head work, so valve springs were a part of this. One thing about valve springs. Too light for the cam, they will float very early and act as an RPM limiter. Too heavy for the cam, they will wipe the cam lobes so quick it isn't funny.

Ray
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party
"Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways totally worn out shouting 'Holy Shit what a ride!"---Crewcheif22 AKA Keith

joe morgan

  • Karma: +0/-0
Re: 1978 glastron/carlson cvx20
« Reply #4 on: June 28, 2012, 04:36:39 AM »
its hard to pinpoint my problems because everything is new. this is the first season the boat has been on the water.  the valve springs are comp
doubles.  The fuel pump is what a plan on upgrading next, its a shitty mr. gasket sh-1 or something like that. My mech fuel pump went out with the old
crusty motor so i just wired this up on friday night.  Crusty motor blew so im still running the pump for now. The boat runs good out of the hole and
planes quick it just doesnt seem to have the rpms I built the engine to run.  The manifolds are long bolts.  I have not trimmed the outlets of the snails
so im still running the 2 7/8 outlets.
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

crewchief22

  • Karma: +66/-0
Re: 1978 glastron/carlson cvx20
« Reply #5 on: June 28, 2012, 06:42:37 AM »
I'd bet the tach is not reading correctly.  Try another tach and see what you get for RPM's.

Speed might not be far off considering the CVX is a relatively heavy boat.  Also could there be saturated foam under the floor that is adding extra weight?
Logged
  • Boat #1: '77 Hondo Pantera GT Jet
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party
"Racing is life!  Anything that happens before or after, is just waiting"    Steve McQueen

The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?

joe morgan

  • Karma: +0/-0
Re: 1978 glastron/carlson cvx20
« Reply #6 on: June 28, 2012, 07:04:52 AM »
The tach is original like all the gauges and switches.  i didnt think it was right just by the way it sounds.
the boat runs well it just lacks a bit at wot.  I can back the throttle off a bit and it picks up a bit.  It sounds
like fuel to me but im just fishin for ideas. the pump is very fresh with a stock A impeller.  I know im a bit on
the heavy side but 58mph is a bit slow, mid 60's sounds better.
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

joe morgan

  • Karma: +0/-0
Re: 1978 glastron/carlson cvx20
« Reply #7 on: June 28, 2012, 05:10:27 PM »
Holley blue with reg. is on the way. I'll see what kind of changes that makes.  Has anybody ever messed with cutting your own impeller?
I have an old A cut that I was thinking of cutting down the veins. The impeller is old and Im not using it in the boat now, I think its worth
trying a A/B cut to get my rpms up a bit more and maybe pull into what I think the engines happy spot is 5200 to 5800 rpm range. Never had the engine on a dyno so dont know hp or torque numbers. Im waiting to see what difference the fuel pump makes at wot before I start doing other
stuff.  Any info about these old glastrons helps.
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

1979CVX20

  • Karma: +0/-0
Re: 1978 glastron/carlson cvx20
« Reply #8 on: January 20, 2013, 09:32:16 PM »
My 79 CVX 20 is almost the same build and I had similar problems. I have started solving them. My boat GPS today 66 mph at 6100 rpm with an xm278 cam (smaller than yours)  which should be more like 5600 rpm when I change from my A impeller to a AA in the spring. Let's compare notes. I have all my part and machining specs and photos  to send. Kept all my notes and receipts. Have been restoring this for over 7 years. Almost done and almost perfected. Most of your problem is carburetor set up which I had.  Sounds like it is leaning out (running out of fuel) when wot. Wrong jets. power valves and possibly timing. I am in Fort Worth, Texas 8179299829
My email thehondspecialist@gmail.com

Ed k
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

1979CVX20

  • Karma: +0/-0
Re: 1978 glastron/carlson cvx20
« Reply #9 on: January 21, 2013, 09:11:45 AM »
7 year restore
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

renegade

  • Karma: +0/-3
Re: 1978 glastron/carlson cvx20
« Reply #10 on: January 21, 2013, 10:51:28 AM »
Id say your tach is faulty. double check that before jumping conclusions, good luck.
Logged
  • Boat #1: 1976 renegade
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party
Whass up!!

1979CVX20

  • Karma: +0/-0
Re: 1978 glastron/carlson cvx20
« Reply #11 on: January 21, 2013, 12:50:40 PM »
Maybe, but it is a digital tach running off inductive pickup on spark plug wire. I just checked to make sure I had it on 8 cyl. and it was. I will try another tach the next warm day.
Engine ingredients:
XM278H K34-241-5 CompCams Kit http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=1002&sb=2
1 pair of  C8VEE heads stock valves new guides CNC ported by Red Man
one set of Ferrea 1.76 exh valves
one set of Ferrea 2.19 intake valves
One set of exhaust seats
ARP Guide plates
ARP 7/16 studs
Roller rockers BB FORD PROCOMP T6 ALUMINUM ROLLER ROCKERS 351C 429 460
Smith Bros, Restricted push rods
Ford Racing Tall valve covers
VC cover stud kit ARP 400-7614 stainless 12 point
Arp intake bolts
10/10 crank
All bearings Clevite
Armondo 10 Qt. oil pan
Mellings HV oil pump
ARP HP oil pump shaft
New  dizzy gear and pin
ARP rod studs
Ford truck rods D6VE-AA
TRW 2404 .030 over pistons
Block bored .030 over stock /decked .029"
Oil drain back holes added or enlarged per HyflowDynamics instructions
Dizzy gear oil modification per HyflowDynamics instructions
ARP HP oil pump drive shaft
Performer RPM Intake
1” Carb spacer
Holley marine 850CFM  double pumper  #80443  Jets #88 Front #96 Rear
  2 Power valves 6.5
front squirter .31 rear squirter .50
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party
Pages: [1]
 


Null

SMFPacks CMS 1.0.3 © 2026