Hi-perf cams for Intake only?
-
kimu
Hi-perf cams for Intake only?
Can someone please explain why it is not necessary to upgrade to 40/80 cam on the exhaust-side?
-
vcg
Who said it isn't? Whith the intake only, you will get around 65% of the bhp gain of what you yould get with both intake and exhaust.
Many people claim low end torque loss, but this Alquati profile is very mild, and my personal oppinion is that in it's full setup both in and ex cams this profile does not hurt drivability (maybe a little weak bottom with a 3.9 diff ratio). Assuming you have decent comression and adequate carburation of course.
Many people claim low end torque loss, but this Alquati profile is very mild, and my personal oppinion is that in it's full setup both in and ex cams this profile does not hurt drivability (maybe a little weak bottom with a 3.9 diff ratio). Assuming you have decent comression and adequate carburation of course.
-
bandit
These Engines seem to run better with a larger intake cam
it gives you a wider power band but thats for a street performance
on a full race Engine you would want both cams to be larger
or close to the same size .
I have done larger cams on the intake and same sizes and
it seems to be a better all around engine with the mix match cams
but no one sells differnt size cams any more only regrinders
can do this for you .
I am sure a few people will disagree with me but i have built
many TC's and like the final out come, theres a few Fiats on
this forum that are using my setup or used to be .
Daniel
it gives you a wider power band but thats for a street performance
on a full race Engine you would want both cams to be larger
or close to the same size .
I have done larger cams on the intake and same sizes and
it seems to be a better all around engine with the mix match cams
but no one sells differnt size cams any more only regrinders
can do this for you .
I am sure a few people will disagree with me but i have built
many TC's and like the final out come, theres a few Fiats on
this forum that are using my setup or used to be .
Daniel
-
lanciahf
On my 2L I installed a FAZA 35/75 on the intake side and re timed the exhaust cam to 110 deg duration. The difference compared for stock is amazing. Pulls hard and fast from 5000 rpms to 6500 unlike before.
Ive Read on Mira the reason the spider engine does not need two performance cams is the head is very efficient the the exhaust valve size is very large in relation to the intake valve size. The thread went on two say two performance cams are beneficial when high compression pistons are used to minimize pumping losses generated by the high overlap of two performance camshafts. Most of this info came from Guy Croft
So unlss you are about to go hog wild on a engine rebuild I wouild try the intake cam upgrade and see if you like it. Make sure you buy adjustable cam pulleys and degree the cams properly.
BTW. When I owned my Alfa spider a popluar upgrade was to replace the intake cam only on Bosch FI Spiders, IAP catalog used to list a cam option for this.
Ive Read on Mira the reason the spider engine does not need two performance cams is the head is very efficient the the exhaust valve size is very large in relation to the intake valve size. The thread went on two say two performance cams are beneficial when high compression pistons are used to minimize pumping losses generated by the high overlap of two performance camshafts. Most of this info came from Guy Croft
So unlss you are about to go hog wild on a engine rebuild I wouild try the intake cam upgrade and see if you like it. Make sure you buy adjustable cam pulleys and degree the cams properly.
BTW. When I owned my Alfa spider a popluar upgrade was to replace the intake cam only on Bosch FI Spiders, IAP catalog used to list a cam option for this.
-
Joe Clemente
- Posts: 151
- Joined: Wed Jan 25, 2006 1:35 am
- Location: Vancouver, B.C. CANADA
I've personally never suffered from from either drivability issues or from compromised performance using both Alquatis in my 2L.
I have read a bit about the intake-only setup on the Mira forum and there are people who tend to swear by it. To be honest, the idea of using only one performance cam, just on the intake, has never been something I would have considered. Especially, as Vassilis said, since 40-80s are fairly mild to begin with. I also would not waste time with cams if I wasn't going to use higher compression. Am I safe in assuming that higher compression is a given here?
I am genuinely curious nonetheless to see some comparative dyno figures to substantiate the claims. Has anybody done so yet?
I have read a bit about the intake-only setup on the Mira forum and there are people who tend to swear by it. To be honest, the idea of using only one performance cam, just on the intake, has never been something I would have considered. Especially, as Vassilis said, since 40-80s are fairly mild to begin with. I also would not waste time with cams if I wasn't going to use higher compression. Am I safe in assuming that higher compression is a given here?
I am genuinely curious nonetheless to see some comparative dyno figures to substantiate the claims. Has anybody done so yet?
-
vcg
Some 6-7 years ago on my stock euro spec 1608 spider I put a 42-82 alquati on the intake only. The only other mod involved was going up in venturi from 32 to 34 and appropriate jetting of course. From 92bhp at the wheel it went up to 101bhp.
A couple of years later I used both 42-82 in my 124 coupe racecar - same engine as the spider, and took it to 125bhp at the wheel (but lots of other mods involved, headwork, header, electronic ignition, etc.).
Most people I know of claim that with intake upgrade cam only you get over 50% of the benefit with both in and ex. I personally consider a figure around 65% a pretty safe guess. But again: the 40-80 is a mild setup so I would recomend to use both if finances allow it.
A couple of years later I used both 42-82 in my 124 coupe racecar - same engine as the spider, and took it to 125bhp at the wheel (but lots of other mods involved, headwork, header, electronic ignition, etc.).
Most people I know of claim that with intake upgrade cam only you get over 50% of the benefit with both in and ex. I personally consider a figure around 65% a pretty safe guess. But again: the 40-80 is a mild setup so I would recomend to use both if finances allow it.
-
Joe Clemente
- Posts: 151
- Joined: Wed Jan 25, 2006 1:35 am
- Location: Vancouver, B.C. CANADA
-
vcg
Hi Joe,
Gozzoli is one of a racer's best kept secrets, and a very highly reputed cam manufacturer in Europe (he also makes tonns of other stuff like valves, manifolds, flywheels, pistons, etc.). I know many people that race with his stuff in FIA race and rally events and all declare very satisfied but avoid to disclose much further information... Personaly I have only raced Kent, Alquati and recently Abarth.
People say his profiles are very sophisticated, and there is a myth around them as there are no regrind copies available and his timings are only revealed to the purchaser and not in catalogs or sites. Two fellow racers use his 318 profile with 45dcoes and 40 chokes on 2.0Lt 131s and get close to 200bhp and I know there are more aggresive profiles than this one, but need deep piston flycuts as TDC lifts are in the 6mm range, so people tend to avoid the hustle. One of them told me about the 318 "that's not a cam - it's a turbo".
In Greece they sell for 700Euro or 350Euro for one plus 19% VAT. Colombo and Newman sell the same, and Kent and Piper significantly less.
I don't know how much of the myth is real, but it's definitely a very solid name in european racing.
Gozzoli is one of a racer's best kept secrets, and a very highly reputed cam manufacturer in Europe (he also makes tonns of other stuff like valves, manifolds, flywheels, pistons, etc.). I know many people that race with his stuff in FIA race and rally events and all declare very satisfied but avoid to disclose much further information... Personaly I have only raced Kent, Alquati and recently Abarth.
People say his profiles are very sophisticated, and there is a myth around them as there are no regrind copies available and his timings are only revealed to the purchaser and not in catalogs or sites. Two fellow racers use his 318 profile with 45dcoes and 40 chokes on 2.0Lt 131s and get close to 200bhp and I know there are more aggresive profiles than this one, but need deep piston flycuts as TDC lifts are in the 6mm range, so people tend to avoid the hustle. One of them told me about the 318 "that's not a cam - it's a turbo".
In Greece they sell for 700Euro or 350Euro for one plus 19% VAT. Colombo and Newman sell the same, and Kent and Piper significantly less.
I don't know how much of the myth is real, but it's definitely a very solid name in european racing.
-
Joe Clemente
- Posts: 151
- Joined: Wed Jan 25, 2006 1:35 am
- Location: Vancouver, B.C. CANADA
Hey thanks for that Vassilis,
I was really impressed with the stuff they carry. 200 hp! Might as well be force fed... That's strong. But then that's where it all comes from I guess, the cams, the headwork and induction.
Interesting what you say about their secretive nature regarding their grind info. Seems a common policy with people making and selling race grinds. I talked to a few suppliers in the U.S. when looking for cams for my Integra for the track. Same deal. Anyway I think I will write to Gozzoli to find out more.
Where did you manage to find a set of Abarth cams Vassilis? Talk about rare.
Thanks again
Joe
I was really impressed with the stuff they carry. 200 hp! Might as well be force fed... That's strong. But then that's where it all comes from I guess, the cams, the headwork and induction.
Interesting what you say about their secretive nature regarding their grind info. Seems a common policy with people making and selling race grinds. I talked to a few suppliers in the U.S. when looking for cams for my Integra for the track. Same deal. Anyway I think I will write to Gozzoli to find out more.
Where did you manage to find a set of Abarth cams Vassilis? Talk about rare.
Thanks again
Joe
-
vcg
Abarth profilo 068 cams are the 8V race cams of 124 Abarth Rallys of 73-75. Their data are 50-68/64-43 FL: 99in 100,5ex 298 dur 4,70 tdc lift 93 overlap and 11,0 FL. These cams give fantastic accelaration and torque and are perfect for up to a fully modified 1800TC (outbored to 1830-40cc) for a 2000 one can go to bigger lift profiles I believe. Fiat works cars went up to 190bhp with them from 1839cc with 44IDFs. 16V with 48IDFs and other cams went up to 215bhp.
These cams are available used or as regring. I use regrind ones from Boubis. Good work nitrided and sharp timing figures. Costs 200Euros for the regrind for both cams. Pretty good deal. I recently got serious power out of them in my 1608 combined with 45DHLA Deloortos and 36 venturies (137bhp at the wheel).
These cams are available used or as regring. I use regrind ones from Boubis. Good work nitrided and sharp timing figures. Costs 200Euros for the regrind for both cams. Pretty good deal. I recently got serious power out of them in my 1608 combined with 45DHLA Deloortos and 36 venturies (137bhp at the wheel).