Hello every one
I am in the process of putting a reco stage 3 9 port on on my 202 powered boat, as i would like a gain in torque and a major gain in fuel economy??
has any one got a guide on how to change a 202 red head???? I need all the torque setting for the head bolts and tightening sequence,
what tappet clearance should i have??
what sort of power and torque gains should the new head give me???
Would a tow cam be of any gain to increase torque even more?
its a standard red 202 with a Varaget II carb
Cheers
Shane J
202 red head settings and Q's
Started by
_RB26DETT_
, Jan 04 2012 06:14 PM
44 replies to this topic
#2
_Bomber Watson_
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Posted 04 January 2012 - 06:58 PM
http://www.aclperfor...pperGaskets.htm
All the sequencing specks are there.
Tappet clearance depends on your cam. If your running a stock cam, or any other hydraulic cam, then it will have 0 backlash, you will need to preload the lifters about half a turn or so after they "rattle" Google is your friend for finding info on this.
Yes a cam change will help. A "tow cam" is nothing and does not exist, what you will want to do is call up a reputable cam manufacturer and discuss the specifics with them, head type, bottom end type, boat weight, etc etc, and have them recommend you one.
You will not likely make a gain in fuel economy at all with either of these mods, but a large gain in performance.
I find it surprising it has a varajet on it.
Any more details on yoru boat, or picks?? I so direly want a 202 powered ski boat to replace the 308 powered flightcraft i have now....Your winging about fuel economy, it costs me $100 to spend two hours on the water LOL.
Cheers.
All the sequencing specks are there.
Tappet clearance depends on your cam. If your running a stock cam, or any other hydraulic cam, then it will have 0 backlash, you will need to preload the lifters about half a turn or so after they "rattle" Google is your friend for finding info on this.
Yes a cam change will help. A "tow cam" is nothing and does not exist, what you will want to do is call up a reputable cam manufacturer and discuss the specifics with them, head type, bottom end type, boat weight, etc etc, and have them recommend you one.
You will not likely make a gain in fuel economy at all with either of these mods, but a large gain in performance.
I find it surprising it has a varajet on it.
Any more details on yoru boat, or picks?? I so direly want a 202 powered ski boat to replace the 308 powered flightcraft i have now....Your winging about fuel economy, it costs me $100 to spend two hours on the water LOL.
Cheers.
#3
_RB26DETT_
_RB26DETT_
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Posted 04 January 2012 - 07:05 PM
the idea is more power less throttle, if i don't have to work it as hard i should use less fuel ie full throttle vs 3/4 throttle for the same speed
just looking for photos of the boat now
just looking for photos of the boat now
#4
_Bomber Watson_
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Posted 04 January 2012 - 07:06 PM
Your idea is good in theory, but doubt it will work in a boat....They love fuel.
Picks picks picks picks!!!!
Picks picks picks picks!!!!
#6
_oldjohnno_
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Posted 04 January 2012 - 09:00 PM
i would like a gain in torque and a major gain in fuel economy??
Did anyone else read that and think of SU's?
#7
_RB26DETT_
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Posted 04 January 2012 - 09:06 PM
i have a current usage of 2L/1Km if i could get 1L/1Km or better i would be very happy
#8
_Bomber Watson_
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Posted 04 January 2012 - 09:26 PM
Its a boat man....
What speeds that at??
What speeds that at??
#9
greens nice
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Posted 04 January 2012 - 09:58 PM
Did anyone else read that and think of SU's?
sure did, a mate made a adapter to bolt a single 2" su onto a variajet mani for his hq tunna, goes heaps better and uses alot less fuel.
#10
_oldjohnno_
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Posted 05 January 2012 - 05:48 AM
i have a current usage of 2L/1Km if i could get 1L/1Km or better i would be very happy
Maybe give it a tuneup before you do anything else, 2l/km sounds horrendous even for a boat. Even if you only averaged 50kph that works out to 100 litres/hr - in other words your 202 is using over twice as much fuel as Bombers 308 boat...
Years ago a mate had a little ski boat with a mild slant 6 in it with triple 1-3/4" SUs. He reckons he got twice the mileage as the V8 guys. He was probably exaggerating but still there was a big difference in fuel usage.
#11
_RB26DETT_
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Posted 05 January 2012 - 08:00 AM
that economy is at about 35kph, and i can only get the motor to rev to 3200RPM (42kph) hence the other reason i was looking into a new head
here are some more photos, the engine photo is before i changed the carb
timing is set to 7deg
this is the towing cam i was also looking at $230 including new lifters and postage
http://www.ebay.com....=item23181b96a7
Part No. Valve Timing Dur .050" L/C Valve Lift Power Comments Dur. Range
Tow IN. 17/59 254 194 112 .382" 1200 High torque, fuel efficient cam with smooth
megatork EX. 65/19 264 202 .408" 3900 Idle, Excellent Towing for STD Motor
here are some more photos, the engine photo is before i changed the carb
timing is set to 7deg
this is the towing cam i was also looking at $230 including new lifters and postage
http://www.ebay.com....=item23181b96a7
Part No. Valve Timing Dur .050" L/C Valve Lift Power Comments Dur. Range
Tow IN. 17/59 254 194 112 .382" 1200 High torque, fuel efficient cam with smooth
megatork EX. 65/19 264 202 .408" 3900 Idle, Excellent Towing for STD Motor
Attached Files
#12
_RB26DETT_
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Posted 05 January 2012 - 08:10 AM
i have also done a compression check and they are all around or over 1000KPA
#13
_stretchlc_
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Posted 05 January 2012 - 11:07 AM
Thats certainly NOT a Varajet Carb I can tell you that much......I have a set of triple 1 3/4" Su's here for sale atm...but with the way the watercooled manifolds on marinising gear are set up, I doubt you'd be able to fit them. Best way to set the timing on these things in my view is to set the timing whilst on the fly. Get this thing on the plane at about 40kph and have someone rotate the dizzy in either direction until it starts to ping and then just pull it back a tad!
#14
_oldjohnno_
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Posted 05 January 2012 - 11:21 AM
There's something drastically wrong, I'd be checking the ignition advance and carb out carefully before swapping any parts. You should be getting at least twice that mileage with the parts you have already.
#15
_oldjohnno_
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Posted 05 January 2012 - 11:25 AM
Thats certainly NOT a Varajet Carb I can tell you that much.....
here are some more photos, the engine photo is before i changed the carb
#16
_RB26DETT_
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Posted 05 January 2012 - 11:36 AM
The carb has had a full rebuild, it could be the ingnition springs and weights but I have no idea what I should use there just using the standard jeep ones that came with delco distributor
#18
orangeLJ
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Posted 05 January 2012 - 11:49 AM
Thats lucky, I thought it looked like a Pro-comp dizzy to start with.
#19
_oldjohnno_
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Posted 06 January 2012 - 05:55 AM
The carb has had a full rebuild, it could be the ingnition springs and weights but I have no idea what I should use there just using the standard jeep ones that came with delco distributor
I'd be having another look at the carb, rebuilt or not. Is the choke fully opening? Or if you can borrow a known good carb test it with that. I'd have one here but I'm a long way from Adelaide... Also put a timing light on it and see what you get at say 2000, 2500, 3000 and 3500rpms. The stock springs and weights mightn't be ideal but they'll be reasonably close, and if you check it with a light at least you'll know that the advance mechanism is working and not stuck solid. I'd suspect carb problems first though.
Does it run smoothly while it's running (and drinking fuel)? You'd think if it's that rich it'd be on the verge of misfiring. What do the plugs look like?
Edited by oldjohnno, 06 January 2012 - 05:56 AM.
#20
TerrA LX
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Posted 06 January 2012 - 07:33 AM
And check how strong your spark is.
#21
_RB26DETT_
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Posted 06 January 2012 - 07:35 AM
the choke has been disabled, i know it is rich at idle but i have been slowly winding it back, and it is helping, i might have a go a tuning it with a VAC gauge when i get home, after doing a bit of reading last night i think the rich idle might be causing low vacuum at idle hence throwing the timing out, as for the plugs they where actually quite clean, but that could be due to the good spark
the carb was rebuilt by a very well known carburetor re builder
i will tate some photos of the carbie once i get home on monday
the carb was rebuilt by a very well known carburetor re builder
i will tate some photos of the carbie once i get home on monday
#22
_RB26DETT_
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Posted 06 January 2012 - 07:45 AM
also remember a boat is under full load all the time unlike a car
#24
TerrA LX
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Posted 06 January 2012 - 08:03 AM
15-20hg
#25
_oldjohnno_
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Posted 06 January 2012 - 12:50 PM
Don't let yourself get distracted playing with vacuum gauges - it's got frOckall to do with anything that matters.
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