Dammakins

Hi Jim - I'm not 100% positive why it why the head gasket blew but I have a good theory - After I drove the car home from getting the original Rochester carb rebuilt and installed (Car previously had a small Rochester carb set up for a small block), I opened it up a bit on the 405 freeway. This was before I redid the whole radiator on the car as I knew it had a problem with overheating - Stupidly pushing the motor caused the temp to almost pin itself to the max temp on the gauge and I had to pull the vehicle off the side of the freeway to get a tow because the motor was smoking. I'm assuming that's likely what caused the head gasket integrity to fail which resulted in the car melting a good chunk of it out. Since then I've re-cored the radiator and its made a world of a difference in terms of temp. Prior to the overheating incident - I could hear the car ping lightly when the RPMs got high or when the motor was pushed.

derekderek

Do you currently have your heads? I just measured my 215 heads, rated at 109 as-cast and they are 100cc's. Get a piece of plexiglass about 6 inches on side. Buy a Walmart flavor shooter. 25cc syringe. Pretty accurate. Drill a hole about 3/8 inch near the edge of plexi. Get some grease and the correct length spark plug. Set head up on a slope so hole in plexi is at the top. Ring of grease between plexi and head deck.

derekderek

These are the basics for an under 10 buck cc-ing setup. I cut the point off the needle so I can draw water back out of chamber and double check. With your pistons, the diff between 100 and 106 or 109 is a must-know. Your 1063 heads are very nice heads-for bringing up the CR of a flat or dished piston engine. You have the opposite problem. You have 30cc domes. Especially since your heads either need or got shaved to repair the burn thru. You mentioned period correct. you can't tell a 65 from an 89 big block head unless you show casting number and date codes under valve cover. These heads are 10 months too old to be technically period correct anyway. Sell these heads. Get 781 or 049. Your giant head gasket problems or replace the pistons problems are no longer an issue. 10.1 with standard head gssket.

derekderek

https://orangecounty.craigslist.org/...589272353.html there is also a 454 block with 990 rectangle heads for 800.

Dammakins

Hi Jim - Just spoke with the machinist who told me he had planned on putting 2.19's in for the intakes. So I guess I'm in a good spot!

derekderek

No, your chambers are still 15 cc's too small and there are zillions of better heads for your purpose. You are fixated on the 68 build year. 049 or 781. And the replacement won't have a head gasket burn.

Dammakins

I'm not fixated on the 69 year for the heads. I'm just frustrated at potentially taking a brand new set from my car that I just got restored, bubble wrapping them up and then putting it in storage for perpetuity. Then having to buy another set for a few hundred bucks and spend another $400 on a valve job for those heads. Basically all the work I just got done was pointless and now I need to redo the same job on another set. Doing that puts me at basically $1,200 in and at that point the question ultimately becomes why don't you just rebuild the whole damn motor in the first place.

derekderek

it sounded like the head work wasn't done yet. but there is these. don't know what o-ringing entails, but... https://orangecounty.craigslist.org/...590922781.html 627990 are what you thought yours were originally. LS7 and Mercruiser 454 Mag heads.

Dammakins

derekderek

See if he can open that lump either side of the spark plugs any. Also help flow. If he hasn't started cutting the ports and seats bigger, he hasn't started the expensive work yet. Ask him what he thinks of 119 chambers with your pistons.

Dammakins

Hi Derek,

Spoke with him yesterday and we both agreed I cannot escape physics so a rebuild is happening. He'll do the machining and I'll do the reassembly in my garage with a co-worker to save some money. From what it looks like, I think I'll probably snag Speed-Pro Forged Pistons L2300NF30 OR something in the same ballpark in terms of size/head volume. The next thing I need to figure out is what cam I'm going to put in this motor. I may be able to use the existing one but honestly who knows since I have no idea what's currently in it.

derekderek

Get a degree wheel. You can download and print for free. Get a dial indicator and stand. 25 bucks harbor freight. Now you have what you need to get lift, duration and open-close events. Another possibility to lower CR is get builder to machine 5 or 10 cc off tops of pistons and/or machine 5 or 10 cc's out of the chambers. I cant use the pistons. Mine are all 454. Diff pin height. I gotta say it 1 more time. It is cheaper to buy heads with 119 chambers and put the 2.19 valves in them. Also, that big lump either side of the spark plug is a flow-power restriction. You will get more power with true open chamber heads with same compression ratio.

Dammakins

I hear you on 119 heads. However, the real root of my problem is the pistons. I understand that I could buy rectangles and get everything where it needs to be - However, by the time that's all said and done and machinist does another valve job on those 119s its going to be another $1k more to just do the entire motor rebuild (Been told it will cost me $1,750-$2,000 all in with parts and labor to do the rebuild if I reassemble myself). While I've been trying to save money, I just came to the conclusion to bite the bullet and rebuild the thing with the proper pistons. I'll also be able to yank the cam and determine exactly what I have in the motor and have the option to change it out if need be. Plus this whole quench drama can be put to bed as I'll be able to get the correct piston to get me to that coveted .040 number. I'll learn loads more about my car and ideally come away with lots of knowledge from this whole experience and hopefully be able to never have to worry about this motor ever again since the goal is to keep this rig for a long long time.

derekderek

Still need a degree wheel to tell what the cam is. You can measure lift with it out, but must have indicator and wheel to get open-close events, duration at .050, overlap, lobe sep angle, all that good stuff.

resdoggie

The real root of your problem is not knowing the cam specs. Once you determine the cam specs, plug in the numbers into a dcr calculator and for pump gas, you want somewhere between 8.0-8.5 as the result. If its not in that range, then play with numbers such as gasket thickness, head cc's, intake valve closing point, static cr, to get in that range. If you're going to spend some money, spend it on a nice set of aluminium heads with the correct cc's based on your dcr number and a new cam. Keep your pistons if the dcr number can be attained with the dome volume and head volume.

I had a similar situation to yours when I did my upper end as in I already had domed pistons that I wasn't replacing. So I worked with the dcr calculator and got 8.4 for my setup by changing the head gasket thickness, cam and AFR heads. It's running on 91 octane with a scr of about 10.7:1. No pinging, but it would be hard to hear over the sound of the side pipes, lol! Engine is still in one piece and it's revved quite often to 6200+.

derekderek

Best bet. Iron rectangle new. https://paceperformance.com/i-625534...50-hp-502.html