valve float...
June-17th-2004, 10:01 PM
#1
Registered User
Thread Starter
Join Date: Apr 2004
Location: Guatemala CA
Posts: 56
valve float...
Hey! I have an other question... At how many revs the engine starts to have valve float on a pro 1.8 DOHC 1991?
It can go without any problem to 7000 rpm and a little more? because i don't know at what rpm cuts off the rev controller...does these pros have rev controller?
I know this engine has its max hp at 6500 rpm but i'm just asking...
I need tips, my brother has a Suzuki Swift GTI and he challeged me in a 1/8 of mile and I need some tips from you racers guys!
It can go without any problem to 7000 rpm and a little more? because i don't know at what rpm cuts off the rev controller...does these pros have rev controller?
I know this engine has its max hp at 6500 rpm but i'm just asking...
I need tips, my brother has a Suzuki Swift GTI and he challeged me in a 1/8 of mile and I need some tips from you racers guys!
June-18th-2004, 05:51 PM
#2
Salt addict
Join Date: Aug 2002
Location: Niagara Falls Ont.
Posts: 1,201
Mine is a BP from a second gen. It redlines at 7000 and the fuel cutoff is at 7200.
I'sd imagine yours would be the same.
As far as valve float, I don't know. That can depend on the condition of your valve springs as much as RPM.
Its a non-interference engine anyways so its not a huge concern.
I'sd imagine yours would be the same.
As far as valve float, I don't know. That can depend on the condition of your valve springs as much as RPM.
Its a non-interference engine anyways so its not a huge concern.
June-18th-2004, 09:24 PM
#3
Got Boost?
Join Date: Feb 2002
Location: New Jersey
Posts: 209
As long as you haven't played with the timing (too much) and you run good gas, they will be fine. The 1.8 DOHC can rev until it hits the rev limiter. If I remember correctly, the rev limiter is 7400rpm and the fuel cut off is 7600rpm.
June-19th-2004, 08:46 AM
#7
Moderator/ Pocket Tuner
Join Date: Apr 2002
Location: Tampa,Fl
Posts: 4,150
the valves have no interference with the pistons anywhere during the stroke in a non interference engine, so if valves started to float at high rpms or you broke a timing belt, it wouldnt seriously damage anything...in an interference engine the the valves are at risk of coming into contact with the pistons should valve float or a broken timing belt occurs...get it??
June-19th-2004, 12:09 PM
#8
Salt addict
Join Date: Aug 2002
Location: Niagara Falls Ont.
Posts: 1,201
Originally posted by 4drmiata
As long as you haven't played with the timing (too much) and you run good gas, they will be fine. The 1.8 DOHC can rev until it hits the rev limiter. If I remember correctly, the rev limiter is 7400rpm and the fuel cut off is 7600rpm.
As long as you haven't played with the timing (too much) and you run good gas, they will be fine. The 1.8 DOHC can rev until it hits the rev limiter. If I remember correctly, the rev limiter is 7400rpm and the fuel cut off is 7600rpm.
Fuel cutoff is the "rev limiter", @7200
June-21st-2004, 11:53 AM
#10
Salt addict
Join Date: Aug 2002
Location: Niagara Falls Ont.
Posts: 1,201
inaccurate tach.
Its not uncommon for them to be off a couple hundred RPm especially in the higher ranges.
Same thing as your speedo. They really aren't 100% accurate all the time.
The only way to be dead accurate would be to hook up a signalling device from the #1 plug wire, the way timing guns are done.
Its not uncommon for them to be off a couple hundred RPm especially in the higher ranges.
Same thing as your speedo. They really aren't 100% accurate all the time.
The only way to be dead accurate would be to hook up a signalling device from the #1 plug wire, the way timing guns are done.
June-26th-2004, 09:30 AM
#12
Registered User
Join Date: Oct 2001
Location: St-Luc, Qc, Ca.
Posts: 137
It is went a valve don't return to the close position.
Let's figure a door with a spring that close the door, like in every shopping mail..etc.. A client open the door. the door close itself. but if the spring is not strong enought, the door take more time to close. lets call that, shopping mail door float.
so on a car. the lobe on the cam shaft push the valve open. then the valve spring pull the valve back close, but if the spring arent stiff enought, the valve dont close at the right time.
Let's figure a door with a spring that close the door, like in every shopping mail..etc.. A client open the door. the door close itself. but if the spring is not strong enought, the door take more time to close. lets call that, shopping mail door float.
so on a car. the lobe on the cam shaft push the valve open. then the valve spring pull the valve back close, but if the spring arent stiff enought, the valve dont close at the right time.
Thread
Thread Starter
Forum
Replies
Last Post
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)