Just wondering what most people do with their cam timing. Do you put it in where it is recommend or do you advance or retard it. What would be the advantages of going one way or the other.
My application I have a 423 sbc. 112 centerline installed @ 112. This is what the cam card recommend. But it has low cranking compression (180) when you check it. Would it be beneficial to advance or retard the cam. Is there any benefit in et or consistency. I have the cam out now so was debating on trying something different.This message has been edited. Last edited by: ts393c,
Posts: 114 | Location: ky | Registered: April 07, 2015
I wouldn’t go chasing cranking compression if you don’t have another reason to change the cam timing. Our engines have about the same cranking compression and run well. Cams are also installed at what the card says.
Posts: 742 | Location: Upstate NY | Registered: July 02, 2013
Originally posted by CURTIS REED: That seems to be a lot of exhaust duration and opens it pretty early for an alcohol engine. How high are you turning it?
7300
Posts: 114 | Location: ky | Registered: April 07, 2015
My set up is close to yours on a 421. engine made 720hp at 7200 with 619 lbs. of torque. Car runs 5.50's @ 2435 lbs. Cam is 278-291* 733-708 lift. 14.25CR with AFR245's and SV2. Wes May 950 carb on alky. My timing is a bit different though, 110 lobe separation with a 106 intake. I set it straight up.
Posts: 476 | Location: BENTON HARBOR, MI | Registered: August 29, 2007
Originally posted by ts393c: Only reason for asking is. I never felt the car ran as good as it should. 6.40 3500# car. It works good and deadly consistent.
That's not bad for what you have. It's really a max effort in between nitrous / N/A.
I've built a few like this, one a 427 went 5 teens 1/8 with 400 on a plate system.
A little more compression and a more max effort N/A cam and it would make 50 more hp for you. This is a in between nitrous cam you have.
We're working on a pump gas in between now similar idea on the cam to run fairly well N/A and exceptionally nitrous.
Originally posted by DLR: My set up is close to yours on a 421. engine made 720hp at 7200 with 619 lbs. of torque. Car runs 5.50's @ 2435 lbs. Cam is 278-291* 733-708 lift. 14.25CR with AFR245's and SV2. Wes May 950 carb on alky. My timing is a bit different though, 110 lobe separation with a 106 intake. I set it straight up.
Sounds pretty good, strong. Try a big radial tire, it'll go a tenth quicker. Smooth well prepped surface, you'll love em, fast.
DLR: My set up is close to yours on a 421. engine made 720hp at 7200 with 619 lbs. of torque. Car runs 5.50's @ 2435 lbs. Cam is 278-291* 733-708 lift. 14.25CR with AFR245's and SV2. Wes May 950 carb on alky. My timing is a bit different though, 110 lobe separation with a 106 intake. I set it straight up.
That is real close to my set up. I'm just a 1000 lbs heavier.
Posts: 114 | Location: ky | Registered: April 07, 2015
Originally posted by Mike Rietow: [QUOTE]Originally posted by ts393c: Only reason for asking is. I never felt the car ran as good as it should. 6.40 3500# car. It works good and deadly consistent.
That's not bad for what you have. It's really a max effort in between nitrous / N/A.
I've built a few like this, one a 427 went 5 teens 1/8 with 400 on a plate system.
A little more compression and a more max effort N/A cam and it would make 50 more hp for you. This is a in between nitrous cam you have.
We're working on a pump gas in between now similar idea on the cam to run fairly well N/A and exceptionally nitrous.
Kirk at Bullet Cams.
Honestly I have always felt the car should run in the 30 to high 20 range. I do run radials. They are a little faster but not much.
Posts: 114 | Location: ky | Registered: April 07, 2015
Blanket statements and misinformation helps no one. The truth and the facts are...I’ve been running radial slicks for over 20 years, 9”, 10” and 14” on two different cars and neither of them ran anywhere near a tenth quicker.
Posts: 13522 | Location: NJ | Registered: August 20, 2000
When using the right cam the only reason to install it a few degrees advanced is to account for timing belt or chain stretch which retards the cam timing.
With your CID, RPM and compression and especially for that weight, you have too much duration. Without knowing the exhaust to intake flow ratio I can't comment on the 14 degree split on duration but I would say it's too much also. Both of these adjustments would close the lobe separation.
If your happy with the current performance then just keep racing, if not them there is room to improve. BTW there is nothing wrong with Comp Cams.
Originally posted by TOP38: When using the right cam the only reason to install it a few degrees advanced is to account for timing belt or chain stretch which retards the cam timing.
With your CID, RPM and compression and especially for that weight, you have too much duration.
Dead on with a zero!
Posts: 13522 | Location: NJ | Registered: August 20, 2000