Notices
Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by: KPower

Mismatching cam timing (maruha)

Thread Tools
 
Search this Thread
 
Old Aug 13, 2021 | 11:34 AM
  #1  
moer_modena's Avatar
Thread Starter
Newb
 
Joined: Jan 2020
Posts: 38
Total Cats: 6
From: Maranello, modena
Default Mismatching cam timing (maruha)

Ok guys, we're rushing to dyno a BP 1.8 naturally aspirated here in modena and we surged against some ... mismatching with the maruha info.
So i try to recall the internet hive mind in order to solve this question asap if possible.
Try to follow me.

The engine is a 1.8 BP mazda, 1993 NA. The max lift as per manual is 111° both for IN and EXH. Maruha PM us a value of 115° max lift for a street use engine.
We installed on the adjustable sprocket and the F-cam from maruha, leaving no offset in the adjustable sprocket an installing them actually as original sprocket.
Now, timing the cams, we found 101° both for IN and EXH. We had expected the maruha cams to be "centerlined" with the original.
We had measured the maruha and stock cams, founding 5° offset centerlining between them (camshaft degrees, so they can account for this 111-101= 10° main shaft degrees offset).

The adjustable vernier pulley allow for a max 6° tuning (so 12° main shaft tuning) in one direction. In order to reach the aforementioned 115° PM from maruha we NEED to "jump a teeth" because we exceed the maximum lenght of the slot (101+12= 113, aiming to 115).

Is this even happened to anyone? Buying from the same vendor i would have expected this not to happen.
Anyway, i always can time the cams to 115° WHATEVER IT TAKES a-la Mario Draghi, jump a teeth, tune with the now sufficient slot and go.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
mx3optidrive
Miata parts for sale/trade
3
Jan 25, 2016 07:47 PM
Madjak
Supercharger Discussion
19
May 29, 2015 07:27 PM
circuitmstr74
Miata parts for sale/trade
2
Dec 6, 2013 12:39 AM
shailoche
Engine Performance
21
Apr 1, 2009 01:25 PM
MapaX5
Engine Performance
0
Mar 15, 2009 11:43 PM




All times are GMT -4. The time now is 02:25 AM.