heads and stuff

[LETZRIDE]

I just bought myself a set of heads from a guy on another forum...hopefully they will be arriving within the next week or so, and I would like to get them in asap...so I need to find out some info.

Heres the background information.

They are a stock set of heads, P&P with manley 1.9" intake valves and manley 1.57 exhaust valves. They come with bronze valve guides that I need to cut down, and will be cutting to clear .600 lift. They were ported by a student in school, and flow benched in shop class. He said that the best intake port flows 208.3cfm at 28" of water. the rest of the ports are within 2% of that as well.
the best exhaust port flows 173.9. and all the rest of the ports are within 3 %.

I am going to be having a shop look over the heads to make sure everything is ok, and maybe touch up any of the runners if need be.

I will be decking the heads 0.010-0.013 and I have 0.052 MLS headgaskets and ARP studs already at the house here.

Questions:

1) With the headgaskets I have + the milling, what size pushrod will I need? I have the stock sized 7.05 right now. I would like to have everything here to start the project, so if I need another size I would like to order it within the next day or so.
2) The heads have bronze valve guides in them...The machine shop I was at the other day told me that bronze valve guides are not good for street driving, they do not like to be heated up for long periods of time, and due to heat caused by sitting in traffic on a hot sunny day, coupled by the fact that they are in a cast iron head (different metals, with different expand/contraction rates) he said that they tend to wear out faster, and that I would be better off going with a solid cast iron valve guide. Anyone have any input on this?
3) anything I need to know as a heads up before this starts? any extra stuff I need/am forgetting? I got my lower intake gasket, and I will pick up a UIM gasket...I have valve cover gaskets...my rocker bolts are reusable, I have new valve seals/locks. The heads are coming with 130# springs which I will most likely sell as I will stick with my 105#


Thanks.

[LETZRIDE]

Re: heads and stuff

bump, want to order everything off today...is there a chart of some sort that would be able to tell you at which compression ratio (i.e milling of the head + gasket) you would need which size pushrod?

[97rs4life]

Re: heads and stuff

there is no chart for what pushrod to go with. You may just need to set everything up and then order your pushrods later after you can measure what size you need if you are unsure

[LETZRIDE]

Re: heads and stuff

there is no chart for what pushrod to go with. You may just need to set everything up and then order your pushrods later after you can measure what size you need if you are unsure

so lets say I set everything up...and I end up needing a shorter pushrod...I don't suppose I can drive around with the stock 7.05 pushrod until the shorter one comes in can I? or what kind of harm would that cause?

[techsan23]

Re: heads and stuff

Alot of times the lifters will compensate for the new valve train. If the lifters cannot compensate for the wrong size pushrod, you will begin to see a wear mark on the valve tip that is offset to one side or the other putting unnecessary stress on the valve. If you are getting close to .600" lift you will need the 130#s. ZZ has a cam that gets .570 lift on intake and .540 on exhaust, and they require 130# on the intake and 105# on the exhaust. They also run 2 different length pushrods between the intake and exhaust. Dont forget the double roller and milled oil pump cover if you use the 130#s. What cam are you going with? If I were you I would order at least the pushrods from ZZ so that Zoomer can review your setup and send you what he thinks you need.

[LETZRIDE]

Re: heads and stuff

I have the abbott racing cam 210/220 .320 lift on a 1.6 rocker. I have emailed them, and he said that technically you should shorten the pushrod the same amount that you are milling/decreasing the gasket size...but he said that the factory ones are already a little short. And the pushrod sizes come in increments of .05...so next size down is 7.00 unless I get it custom made... I don't have a double roller timing chain at the moment, that will go in mid summer...thats why I would much rather stick with the 105# springs for now....I won't be going close to .600 lift until I do rocker arms...I'll probably do a 1.8 roller rocker, but not for atleast a year or 2...and by that time I may just opt to go with a bigger cam instead...but the guides will be cut for it for when the time comes.

[LETZRIDE]

Re: heads and stuff

ok, Ive been told that the factory size 7.05 push rods are slightly short...does anyone know how much they are short? cars loosing 0.02 total with the head gasket and milling...anyone mill there heads that much? I know some people who have heads must have lost 0.02 off there heads at some point? what size pushrod were you using?

[techsan23]

Re: heads and stuff

My heads were decked .005 + block .005 + .052 cometic gaskets = .02". I even ordered an adjustable pushrod to check length. I was emailing back and forth to Zoomer at ZZ, and he assured me that the custom length pushrods I would get with the yella terra roller rockers would work well with my setup. When I tore that engine back down there were light rectangular marks dead center on the tips of the valves. I never did measure those pushrods though. You probably already know this, but be careful when your talking lengths that you know exactly how the company measures the part. Base of ball tip etc.

http://www.compcams.com/information/Products/Pushrods/

[techsan23]

Re: heads and stuff

I remember why I ended up not using the pushrod length checker. I figured the lifter was going to collapse when I tightened down the rocker, and it was my impression that I would need a specific solid roller lifter to get an accurate measurement. So when I was assured that the yella terra's would work I got anxious and gave up.

[LETZRIDE]

Re: heads and stuff

I remember why I ended up not using the pushrod length checker. I figured the lifter was going to collapse when I tightened down the rocker, and it was my impression that I would need a specific solid roller lifter to get an accurate measurement. So when I was assured that the yella terra's would work I got anxious and gave up.

so you were using the stock sizing then eh?

[techsan23]

Re: heads and stuff

so you were using the stock sizing then eh?

They are simply listed as custom length on zz's site. Its like its a big secret or something. I emailed yella terra; if they get back with me I'll let you know. I guess people are afraid that if you know what you need you'll find a deal on them elsewhere.

[LETZRIDE]

Re: heads and stuff

well, I've been doing a bunch of research...seems like I found out that the "actual" stock length is 7.03, we are ok to use the 7.05 length though, because the factory 7.03 is actually a bit short. so by this logic, I am thinking of gaining the 0.01 with the gaskets, and then mill the heads 0.02 for a total of 0.03. By doing this, my thinking is, if I am still ok to use stock size, the way I am now and that's 7.03, then if I take .03 off, it should definetly be a 7.00 pushrod...but since right now I am getting away with a 7.05 pushrod, I will still have a little leway with the 7.00 pushrod just like I did with the factory pushrod on these motors.

If any of that makes sense^

Now I also learned that the OEM lifters and OE850 lifters have alot more play and can take alot of the load, where as the compe OE-R lifters have very little room for play...you pretty much have to be bang on with your measurements.

lastly, although I have read that decking the heads 0.02 is quite a bit...correct me if I am wrong, but they say that is alot if you ever intend to spray, or go FI...I intend to do neither, and I have the Cosmetic head gaskets which I intend to install the "modded" version way. As well as I have Arp head studs which should give me sufficient clamping force.

This overall should give me a 0.03/0.06 = 0.5 increase in compression....therefore I should be running 9:9:1 < anyone think that is an issue on 91 octane pump gas?

[Bandit127]

Re: heads and stuff

92 octane should be absolutely perfect in your engine. As long as you keep your cylinder head temps down and watch your knock, I see no reason why you will have a problem. You'll tune to your new compression anyways. I give thumbs up! Nice research btw.

[ssms5411]

Re: heads and stuff

I've been running 9:8.1 for about 8 years 9:5.1 Diamond forged pistons and have used a Powerdyne and then 125+ shots of nitrous, GM head gaskets Comp. 7.05 pushrods and Comp OER lifters and highest I can run in AZ is 91 octane at the pump. I will be going to a .065 MLS head gaskets +.3 compression for the promags and pushrods , COMP OE lifters since they are queiter than the OER's , and still saty with COMP 7.05 pushrod but .105's instead of 5/16th pushrods and COMP 1.7 Pro MAGS. If I go with new psitons JE forged 9:9.1 pistons and milled heads to get a 10:1 compression and still be able to run 91 octane, with methanol injection for the turbo and low boost in summer times.

[LETZRIDE]

Re: heads and stuff

discussed this with a few buddies, they seem to think that the 7.00 pushrod will work...just wondering what would happen though if the pushrod ends up being 0.005 short? If increasing the rod by 0.02 was fine, I don't see why being 0.005 short would be bad, but trying to get a better understanding of how exactly the pushrod works in the engine.

I pick the heads up tommorrow.