So I have this cam back...seeing my trust is totally eroded with my current builder...I overheard him mention who did my cam. I called them, they grinded from a used buick 300 cam shaft. He was real vague on a number of things, but here is what he told me. He is limited by what he could do, it's very mild, Lift @ 50 .300. Duration @ 50 255. Said I had to multiply that by my rocker ratio?? I had lifter issues. They would not hold pressure. He mentioned that because of cam grind that maybe lifter priming hole is misaligned??? I just do not want to stick this cam in there to find that my engine runs like a dog after having spent all this money. I did not pay any money for the cam I have, soooo if I need to buy a new one, I prefer to do that than be disappointed. I really liked the 110A from POSTON BUICK but did not see anything out there like that. (plus allows me to keep the current valve train...unless position lifters had different height...). Not so simple.
Comp Cams supposedly has cam cores according to this article here. They can custom grind a cam. I had one ground for a 455 and it was dead on to the cam card. They have a few lobes close to the .050" dur. in there high energy and dual energy line-up. If you go to there website and download the Cam Lobe Master Catalog in PDF. As an eg in their dual energy line-up there is 2 lobes close. You just ask for these lobes and what LS you want which the one was 110*. Lobe 5128 273/211@.050", 472" w/1.6 rocker. For the Int.. Lobe 5326 275/219@.050". 477" w/1.6 rocker. For the ex.. One thing to watch out for on the 300 is the retainer to valve boss clearance any cam over .450" lift should be checked. My old 300's valve tips were being pounded by the rockers with .488 lift cam as the retainers had no clearance. Ray
The Poston SB110 and the SB110A are different cams. You list the SB110 in your signature. Are you looking for a cam card for the SB110 or is the SB110A the correct one? Ray
Was looking for the 110A. I had the 110 prior to my engine rebuild fairy tale. LOL. I figure with the porting and the high comp pistons that the 110A would have provided some additional fun factor. I was looking at D&D fabrication in Michigan, they seem to have a nice selection of cams.Mind you they are all Crower cams...but I need intake gaskets and he may stock. Looks like I can order all from his shop, plus he is closer than most. I also want to order a variable oil pump spring and some gaskets for shimming. I can get those from TA Perf. However they do not seem to have any cams for 300. http://www.aluminumv8.com/catalogpages/enginecomponents.htm
Thanks Ray, Your technical savvy is at a higher plane than my current abilities. But I gather you are proposing a cam that is somewhere between the 110 and the 110A. My rocker ratio is 1.5 so this would be close to the 110 right?
Michel the rocker ratio on a 300/340 is 1.6/1. If you liked the 110 cam so much I would just go a little more radical on the ex side due to help the exhaust flow. Also using a little more ex duration usually broadens the power band. However guide boss clearance could be an issue and should be checked with any cam. Like I said some of my tips were hammered as well as a few bent pushrods. I ground down all my ex bosses and removed the seals. I just looked up the lift I have and it is .454" int .484" ex.. I have a 204*/216* on a 112LS cam (-14 O/L) in the 300 I'm pulling soon. It idles rough when first fired up then smooths out. Likely the same overlap as yours was if it was 206*/206*@.050" on a 110. To get the overlap add the dur#s at .050" divide by two (yours 206) then minus the LSx2 (220)= -14 O/L. I think you could use a little more radical cam but I would try to use lobes that will not need the valve guide bosses machined for clearance. Ray
Off the site link the Crower 50231 looks good. It's a little more cam than the 110. Summit has the specs Crower 50231. The Crower site is down. 270/276 210*/218*@.050 .451"int/477"ex LIFT LS 112 This would give you -10 O/L so it would raise the power band a few hundred rpm. The rule of thumb is every 5* O/L raises the powerband 500rpm. Ray
I really do not know how to compare these specs to the specs I was given by my builder on the cam he supplied. Here is what he gave me: LIFT - @ 50 - 300 x rocker ratio 1.5 = 450 DURATION - @50 - 255 x rocker ratio 1.5 = 382 Which numbers do I compare that to on the above cam card. I know above is 110a, I originally had the 110, I suppose if it's at least equal to the 110 or better I will install. I am going by memory... do both these numbers get x by 1.5 or just the lift get x by 1.5?
Not to hijack, but I am considering pulling the cam out of my 300 as well. It is a '64 aluminum head engine with maybe 9.8:1 compression, bowl ported heads, but stock valves & springs (but they are new). It has a TH350 with a 2000-2200 stall converter. Seeking a recommendation for a flat tappet hyd cam that will make power 4500rpm and below, utilizing the stock valve train. I'm not looking to rev this motor to 5000rpm on a regular basis, but I am looking for a moderate improvement in performance. Any ideas?
Looks like he gave you the advertised duration (255) and the lobe lift (300). To get the lift multiply 300 by 1.6 (480) So you have a cam with 255* duration and 480" lift. The specs for the .050" lift degrees and lobe seperation are not there. Ray
They started with a stock cam and gave it that grind...not sure if that helps...so it looks better than the 110 but not as strong as the 110A? Told me it would be good from 1500 to 6000 RPM. My stall is 2200 RPM, Tires 27 inch, rest of the details required are in my signature. Ray, you're positive on the 1.6 ratio?
Ray is correct. 1.6 ratio for the 300 rocker arms. I have been told that the manufacturing tolerances were fairly inconsistent, but that the published ratio was in fact 1.6, not 1.5 Did you get the stuff you needed from D&D? They seemed pretty knowledgable regarding the 300 engine when I talked to them months ago. How did you like your Poston 110 cam?
Those specs don't tell you anything about how to install the cam. I would not just install it and line up the dots on the timing chain. You need to get a degree wheel and dial indicator then measure the cam at the opening and closing points and see what you have. There is a Thread from JW on how to do it in the Street/Strip forum. This will also give you the .050" specs as well as the L/S. The most important spec is the int. closing. At the very least I would match the closing point of the original sb110 cam as it worked well with your high compression ratio. If the original sb110 was installed 4* advance it would have had an int. closing point of 56* ABDC. Use .006" lift when you take your * measurement. This would be on the closing side of the int. just before the base of the lobe. You also need to check for retainer/guide boss clearance and lifter preload. Ray
Ray, It's all chinese to me (ABDC L/S)! I have never done this before. However, my brother use to work for Ford of Canada, one of his friends is pretty well known on the race circuit and has built his share of race engines has indicated that he may be able to come over when I have all my stuff ready and he will help me do all these things you are talking about. You sound way to smart for your own good. LOL! If I am on my own it's going to be dot to dot. I think I am going to work with the cam I have. D&D did not return my call, I have had enough of that s*&t, last thing I need is another vendor relationship like the one I just broke off. I am off to the east coast early tomorrow, back on Sunday.
How do I find out what intake centre line is on this cam I have? They started with a stock cam...is that something that only the fellow who ground it will know? EDIT: Talked to Grinder man. They did not change the centre line on the cam, just lift and duration. So question is what was the factory intake centreline at?
The intake centerline only tells you where the highest point of the intake lobe is loacated. If you go through the steps on this link 1 through 5 it is explained really well. Print it out. If you follow the process it will give you the all your cam specs. Opening and closing advertised specs as well as measurements @.050" and the cam's LSA. Ray
R67Beast, I have read through the link that you posted. I am going to have to read through that link several times before I can truly understand what is happening and what the measurements are telling you, and I really do want to understand this. I have one question: I have no idea what cam is in my engine. All I know is that it is aftermarket and that it is visually in good condition, and that I would like to degree the cam to make sure it is installed properly, because I an confident that it is not installed properly (optimally). I have no cam card for this cam. Will the method described in the link that you posted allow me to essentially create my "own" cam card and get the cam installed properly, or not? Thank you.
Thanks Ray, My cam install guy said he needed to know what the starting point was for that cam. If my cam grinder guy says he just changed duration and lift using an OEM 300 CI cam would the starting point not be available or do I still need to go through 1-5 in that post to determine that? Sorry for what may seem like a dumb question. I too went through that post on the street and strip section and would probably need to review 10 times and maybe I will get some of it.
David the way Jim does it will tell you what the measurements are as said if the lobes symmetrically shaped (the same). Most cams are ground this way. Checking a cam this way against a cam card will also tell you if the card is correct. Many cams I've measured were a little off. Doing it this way you will know one way or another. If the lobes are asymmetrically shaped all bets are off but it should still get you close. Asymmetrically shaped means not the same. For example the comp cams intake XE lobes and XE ex lobes are different. Ray
