jeepnotch88

Ok guys 1988 Mustang speed density. stock bottom end. GT40P heads, Cobra upper and lower intake, 1.72 FMS rockers. What camshaft can I run with this setup?
I need to replace the front cover gasket so why not swap the cam I guess...
Thanks
Notch

Portmaster

Comp XE264HR for use with 1.7 rockers and OBD1 but you will need compatible springs

mjr46

do away with the speed density first, convert to mass air and then the world of cam selections will be larger in selection.

Joel5.0

Would a -4° overlap @.050" suffice for SD?... nope ... the cam specs call for a .512" max lift, since the GT40p heads are done at .480" lift, why use the 1.7 rockers (.546" lift with the XE264HR cam)?

Portmaster

He asked what cam he could use with what he had. I told him

I answered his question directly because he asked what would work with his speed density system. He didn't ask about changing it to mass air, he didn't say he wanted to buy new rockers but a simple cam swap. The SD system sure isn't optimal, The GT40p isn't optimal and personally had I had that set-up I'd leave the stock cam in it until it had at least had a MAF system on it but he didn't ask that either. Because the cam has a better profile and opening and closing rates it would be an improvement over the stock cam with SD. Yes it lifts the valve past where I would want it that why I told him to get compatible springs. But it also holds the valve open longer. In the other case that you are trying to rub my nose in the guy was ordering parts. I told him to back off the 1.7 rockers with the cam he was using becuse it adds extra valvetrain stress so he would be better off with 1.6 rockers being that he was ordering them or so was my understanding.

Instead of spending so much time trying to find fault in what I say why don't you try to answer the OP's question? While I don't doubt you could find a better cam for his setup by giving him Jay Allens phone number or web address I'd sure like to see you put yourself out there from time to time instead of just going around trying to find fault in other people. If you really want to prove yourself pull a better OTS grind for this guy than I did and if you do I'll give you props for it. I never claimed to be the master of cam selection but I can pull some OTS grinds that work well. Come on I dare you to impress me without trying to talk over the OP's head so far he thinks you work at NASA. Trying to kick me around like an old dog without giving the OP an answer is just being a E-Thug. If you want to kick a dog I suggest you get your own as I will not give you the pleasure (that you so dearly seem to love) by replying to any more of your E-Thug tatics.

crueheadstang87

I totally agree ^^^

jeepnotch88

Wow such tempers here! Sorry if I had a bad question....
If I back off to 1.6 rockers and still stay SD what options do I have? I just can't pull enough cash to do it all at one time cam, rockers, mass air swap.
Is there a cheap mass air swap I can do?

Thanks, notch

Rajun_Cajun

Dont worry, they do this in every thread. LOL If an E-303 can be used with SD, I have one for sale. PM me.

93 LX FiveO

i just got a similar setup and with the stock cam ill be running .471/.471

stock cam is .444 with 1.6 ratio

Joel5.0

So it was a valve train stress issue there, and is not an issue here...... same type of cylinder heads, GT40p. And the other cam, even though has more duration doesn't hold the valve opened longer. Add that to a more aggressive XE lobe here..... which one will have more valve train stress?

In case you missed what I was trying to do, here it is..... there are two versions of the XE264HR profile. One has a -9° overlap @.050" (not -4° as I typed by mistake) which is not compatible with SD (#35-320-8) and the one that specifies/suggests the use of the 1.7 rockers..... The other XE264HR profile (#35-349-8) which has a -13° overlap @.050", same lobes with a wider LSA (114°)...... or "SD friendly". Now..... don't you think I was trying to help the OP, preventing the mistake of ordering the wrong XE264HR if he so chooses to buy it?

Sir.... I don't need to impress anyone, nor do I evade the tech questions, or make statements (like yours in bold above) that are in contradiction one with the other. Here's a tech question regarding the "if GT40 heads quit flowing past .450" valve lift, it doesn't make sense to open the valve past that maximum flow point" concept you follow. How could a 302 with GT40 unported heads, stud rockers conversion, with a 227/252 @.050" .563"/.547" lift with 1.6 rockers camshaft, daily driver, 100% N/A run 11.19 @119 MPH in the 1320'?

If you take offense with my inquiries, my apologies then, I don't want to hurt your E-feelings....... but that doesn't mean I should standby and watch how choking an engine "advice" is given to promote performance gains and do nothing.

jeepnotch88, if an MA conversion is not planned, cam selection is important. You wouldn't want to select a camshaft based on SD compatibility, find out it's not, and end up with a MA converted setup with a cam that was selected for SD. Here's another option......stock cam with mixed rocker ratios (1.6 intake/1.7 exhaust or vice versa) + better springs + degree the cam to find out the best timing spot..... it does net good performance results for a SD system....... while you plan a better setup.