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Topic Review (Newest First)
07-24-2010 10:42 PM
cobalt327
Quote:
Originally Posted by crussell85
I have the lifter out of a 4.3 liter v6, they are oem lifters. I can use these on the retro cam right as long as I stay below your recommended lift?
Yes, you can- as far as I know. I have NOT done this personally, although I did do quite a bit of looking around here and elsewhere, and I find nothing to the contrary.
07-24-2010 10:24 PM
SSedan64 The 90* 4.3L OE Roller V6 uses the same lifters as the 90* OE Roller SBC block, so yes as long as you have 16 lifters. V6 only has 12.
60* 2.8, 3.1 & 3.4L V6 lifters are .200" shorter and work in (Non) Roller SBC blocks.
07-24-2010 09:59 PM
crussell85 [/QUOTE]There are both vertical and horizontal links for retro lifters.[/QUOTE]

I have the lifter out of a 4.3 liter v6, they are oem lifters. I can use these on the retro cam right as long as I stay below your recommended lift?
07-24-2010 07:16 PM
cobalt327
Quote:
Originally Posted by crussell85
so if the block is a factory oem tbi block 87-95 and I use factory lifters with the dogbone and spider I could use a retro cam with a thrust button?
Yes- as long as the lobe lift is what I said above, or you find out the info is wrong.

There are both vertical and horizontal links for retro lifters.
07-24-2010 07:12 PM
crussell85 so if the block is a factory oem tbi block 87-95 and I use factory lifters with the dogbone and spider I could use a retro cam with a thrust button?
07-24-2010 07:07 PM
cobalt327 Yes, but if it is a Vortec w/the plastic cover, you will need to deal w/converting to a different timing cover- the Vortec type plastic cover has different locating tabs than the steel OEM cover and is missing a couple tapped holes in the block.

If you have an earlier OEM roller block, they use a conventional cover, so all would be similar to any retro camshaft install.

Supposedly, 0.353" lift at the lifter is all the OEM lifters are good for. There are aftermarket lifters to increase this if needed.

07-24-2010 07:07 PM
eric32 You can use a retrofit roller cam in a oem roller block but you will have to use the timing chain and a roller button that goes with it and also you can not use retrofit roller lifters in the block cause the link bar will hit the top of the lifter pad where the dog bones go unless you grind them down.

That is what I have read in some chevy high performance mags over the last couple of years . You can use oem roller lifters with the retrofit cams but they recommend no lift over 530 with 1.5 ratio rockers.

The reason on the lift part is that the lifter can ride up so high and then go down so low that not enough of the lifter crown will be held in place and they can get knocked out of the dogbone and then spin. Many of the after market cams like comp cam's cast roller cores are made on a smaller circle base and that is what causes some of the issues.

Some have said they ran more lift then that with them but that was what was stated to be on the safe side.

I have read this information on some articles and it was about roller cams and other stuff on them and the things mentioned above was from some guys who was with crane. I hope that will help but but some is from reading on other peoples experiences so take it as opinions and one way but not the right way necessarily.
Eric
07-24-2010 05:29 PM
crussell85 just out of curiosity will a retro cam work in an oem roller block as long as I use the old style timing set and a thrust button?
07-22-2010 07:05 PM
techinspector1
Quote:
Originally Posted by crussell85
http://www.summitracing.com/parts/TFS-31402000/

sorry about that, i checked them and they worked on my computer
Too short for 10.5 SCR. (needs 235-240).
Too short for 10.0 SCR. (needs 225-230).
Just right for 8.75-9.75 in my opinion.
07-22-2010 06:49 PM
crussell85 http://www.summitracing.com/parts/TFS-31402000/

sorry about that, i checked them and they worked on my computer
07-22-2010 06:21 PM
techinspector1 Your links are bogus.
07-22-2010 06:15 PM
crussell85 I am learning, I think? I have been reading on and off when I have time. I know now more about the duration and overlap and all of the other good,confusing stuff. I am no camspert but I am closer than when I started this post. I was cruising around the www.summitracing.com site and seen this. I ran the cam through the hotrodders search feature and seen that another person had asked about the cam but I was just kind of curious. I see that cobalt said in that post the he don't like to select cams for people because the person that asks always knows better and basically doesn't want to admit that their setup is not "setup". But anyways here is the link, so let me know if you would. I understand the compression ratio is high for what I am wanting to do, but lets just say for the the way engine is setup right now would it be a cam in a list of options?

http://www.summitracing.com/compare.aspx
http://www.summitracing.com/compare.aspx
04-16-2010 05:43 AM
cobalt327
Quote:
Originally Posted by crussell85
The thoughts that I am having is that I need less duration because I am holding the intake and exhaust valve open together to long and am dumping raw fuel out the exhaust.
From what I have researched and read this is the cam (08-465-8) I came up with http://www.compcams.com/Cam_Specs/Ca...?csid=206&sb=0
It is also one that comp cams recommends in their cam selection software. I ran it on my Desktop Dyno and it is showing a great amount of improvement. I was just wanting some feedback or a straight up yes or no before I would commit to buy.
What you're running into w/the cam you've selected, is a cam w/"short" duration and basically no overlap in combination w/a static CR of over 10:1 being too high of a 'dynamic' CR. There will be enough "efficiency" of the small cam to actually cause the 10:1-10.5:1 CR (or whatever it is, exactly) to cause detonation. When that happens, power takes a nose dive and parts breakage will happen.

You need to lower the static CR, OR choose a larger cam, duration/overlap-wise and the gears and torque converter to make it all work together.

The cam Comp spec'ed for you presumably has specs that will allow your CR to be compatible w/the cam and the rest of your combination of parts and gear ratios. It would be a better choice, IMO than the cam you picked. Is there a reason for not going with Comp's recommendation?

Here are the specs, from them you can see how the cam Comp suggested will not have as high of a DCR as the "little" cam you picked for yourself.

252XFI HR13 #08-464-8
Intake open 17BTDC close 55ABDC
Exhaust open 69 BBDC close 15ATDC

Comp's choice: XR269HR #08-502-8
Intake open 26BTDC close 62ABDC
Exhaust open 74 BBDC close 22ATDC

I hope this helps you, and doesn't just confuse the issue more.

Good luck.
04-16-2010 12:58 AM
F-BIRD'88 The compreswsion ratio is too high. Get some dished pistons.
Get the measured cr down less than 9:1.
04-15-2010 07:05 PM
crussell85 anyone? anyone?
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