Pics of my progress and a question.

68stang351 · Apr 8, 2010

I started my heads/cam swap. Just waiting for a few more parts to come in now.

Snapped these.

Now for the question. Is this thing going to be a dog with these stupid pistons??

I wanted to when I pulled the heads off and saw that.

The dish is huge, it's almost a 1/4 deep, I think I mic'd it at like .23" or something like that. I'm thinking the compression could be as low as 8.8 or 9:1. Almost makes me want to put stock stuff back on.

Here's the combo
69 351w with stupid pistons
TFS twisted wedge 2.02/1.60, 170cfm intake 66cfm exhaust, 61cc chambers, 1.6 rockers
Comp 292 cam .518/.518, 242/242 duration, adv @ 292
(still considering the XE 284 .541/.544 240/246 284/296 adv
Performer RPM intake

jerry S · Apr 9, 2010

It is an opportunity. You know how they say "when life gives you lemons, make lemonaid?" In your case, when life gives you low compression pistons, put on a supercharger.

jasonn · Apr 9, 2010

Same pistons I have in my mach. I have stock 69 heads that I ported a bit when I was really young. Small solid flat tappet. perf rpm intake with 1 5/8 headers. It runs mid to high 12's. Runs great. Leave it alone, it'll run great with the new parts. BUT, AT LEAST run the xe cam or go custom for a few more $'s.

68stang351 · Apr 9, 2010

jerry S said:
It is an opportunity. You know how they say "when life gives you lemons, make lemonaid?" In your case, when life gives you low compression pistons, put on a supercharger.

Yeah that would be great if I had loads of money laying around.

jasonn said:
Same pistons I have in my mach. I have stock 69 heads that I ported a bit when I was really young. Small solid flat tappet. perf rpm intake with 1 5/8 headers. It runs mid to high 12's. Runs great. Leave it alone, it'll run great with the new parts. BUT, AT LEAST run the xe cam or go custom for a few more $'s.

Thanks, that makes me feel a little better. The cam is the only thing I haven't ordered yet because I can't decide. CamQuest6 shows both these cams as great fit for my application, though the XE has 4 more average hp.

68stang351 · Apr 9, 2010

Ordered the XE284 today. Hope it fits. I wouldn't think that would be much of a problem with the mile deep dish though.

woodsnake · Apr 9, 2010

Of course you're still going to measure PTV clearance, and check your valve train geometry, right?? Installed spring height, etc, etc.....

This cam?

http://www.summitracing.com/parts/CCA-CL35-246-3/

2+2GT · Apr 9, 2010

68stang351 said:
Now for the question. Is this thing going to be a dog with these stupid pistons??

The dish is huge, it's almost a 1/4 deep, I think I mic'd it at like .23" or something like that. I'm thinking the compression could be as low as 8.8 or 9:1. Almost makes me want to put stock stuff back on.

Look at it this way, you'll be able to use pump regular.

Even the stock 351 4V had flat tops, but I'd be surprised if you're losing more than 15-20 hp.

If it really bothers you, spend a couple hundred on flat-tops.

68stang351 · Apr 10, 2010

woodsnake said:
Of course you're still going to measure PTV clearance, and check your valve train geometry, right?? Installed spring height, etc, etc.....

This cam?

COMP Cams CL35-246-3 - COMP Cams Xtreme Energy Cam and Lifter Kits - Overview - SummitRacing.com

Yes, of course! But it's this cam.http://www.summitracing.com/parts/CCA-CL35-250-4/

2+2GT said:
Look at it this way, you'll be able to use pump regular.

Even the stock 351 4V had flat tops, but I'd be surprised if you're losing more than 15-20 hp.

If it really bothers you, spend a couple hundred on flat-tops.

Nah I'm not going to worry about it, I'm going to put it together and enjoy whatever it gives me. At least it will be faster than it was.

Extra bonus for me:
The D0OE heads I took off are going onto my 90GT with a comp roller .512/513 lift and adv duration of 284/296 that I picked up for cheap years ago. That car already has intake, full bolt ons, gears, it should run real good too!

brianj5600 · Apr 10, 2010

That cam with TW heads is very likely to kill the valve when they get smacked by the pistons.

68stang351 · Apr 10, 2010

brianj5600 said:
That cam with TW heads is very likely to kill the valve when they get smacked by the pistons.

Obviously I will not run it if it has interference problems. I'm not a moron.

65ShelbyClone · Apr 10, 2010

2+2GT said:
Look at it this way, you'll be able to use pump regular.

Even the stock 351 4V had flat tops, but I'd be surprised if you're losing more than 15-20 hp.

+1.

If pulling the engine and installing new slugs is not in the cards, then just leave it alone. It's still going to be a strong runner. Besides, you can't miss power that you never had, right?

68stang351 · Apr 10, 2010

65ShelbyClone said:
+1.

If pulling the engine and installing new slugs is not in the cards, then just leave it alone. It's still going to be a strong runner. Besides, you can't miss power that you never had, right?

You're right, that's what I'm doing.

Since I'm just waiting on parts at this point, I spent the whole day degreasing, painting, and clearing, my intake, timing cover, water pump, alternator, bracket and spacers, balancer, and timing pointer. I may get pics up later if anyone cares to see them. This motor is going to make the rest of my bay look like crap.

Oh and for Brianj5600, I stuck in a cam I had laying around with the same duration, but with .512/.513 lift as opposed to my cam's .541/.544 lift, and clayed the piston to valve clearance, and with the clay at .6 thick the valves never even touched the clay, so .......... I don't know if you caught it but in my first post I stated that the dish is about a 1/4 inch deep..

brianj5600 · Apr 10, 2010

I was not trying to insult you. I was short on time. The pistons I have seen that have reliefs for TW and inline valves look like it would put the valve where it hit the top of the piston and not the dish area. I am sure you will check again once all the parts come in.

68stang351 · Apr 11, 2010

brianj5600 said:
I was not trying to insult you. I was short on time. The pistons I have seen that have reliefs for TW and inline valves look like it would put the valve where it hit the top of the piston and not the dish area. I am sure you will check again once all the parts come in.

Sorry, I misunderstood you.

I actually thought that also, with the valve being relocated like it is, so that's one of the reasons I checked it. I think the dish is just so big that the valve is still coming down over it anyway. My friend was trying to get me to not check it but I'd rather be safe than sorry, and I'll check again when the actual cam I'm using comes in.

I tell ya though, I'm nervous about breaking this thing in. I've always messed with roller cams so I've never broken one in before, and I've heard some bad stories.

I can't wait until it's back on the road though so I can just cruise around on back roads.

2+2GT · Apr 11, 2010

68stang351 said:
I actually thought that also, with the valve being relocated like it is, so that's one of the reasons I checked it. I think the dish is just so big that the valve is still coming down over it anyway. My friend was trying to get me to not check it but I'd rather be safe than sorry, and I'll check again when the actual cam I'm using comes in.

I tell ya though, I'm nervous about breaking this thing in. I've always messed with roller cams so I've never broken one in before, and I've heard some bad stories.

The deep dish in your pistons is in the center, where the valve reliefs would be.

View attachment 223167

As for the break-in, I have always used STP oil treatment. Brushed on the cam lobes, and dip the lifters before installing.

Turns out STP, especially the red label, has more than enough of the ZDDP to make up for lack of it in most motor oils.

brianj5600 · Apr 11, 2010

No apology needed, I can see why you reacted.

I can't find red bottles around here. I used it when I could find it.

65ShelbyClone · Apr 11, 2010

Something else I have heard of others' using for breaking in flat cams is GM Engine Oil Supplement. I have not tried it personally.

68stang351 · Apr 15, 2010

I've got the heads torqued down, cam and lifters in with the timing set on, timing cover, water pump, balancer, alt, pullies, brackets, radiator, back on. It's starting to look like an engine again.

Tomorrow while I'm waiting for my pushrods to come in, I'm going to put on the headers, intake, carb, and distributor, and change the oil. Then it's just putting in the pushrods and adjusting rockers.

I can only work on this for about 2-2.5 hours at a time each day after work. After that it gets dark and the bugs start harassing me, so I come home and spend time with the wife.

Hopefully my pushrods will come in tomorrow and I'll have it going this weekend.

downwardspiral · Apr 15, 2010

65ShelbyClone said:
Something else I have heard of others' using for breaking in flat cams is GM Engine Oil Supplement. I have not tried it personally.

Joe Gibbs makes a good break in oil.. its not cheap though.

68stang351 · Apr 17, 2010

It lives!

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