Help me recover from DIY Port and polish mistake

[Kapper]

OK, so I'm a noob at this stroker build stuff, I took some bad advice about the DIY Port and Polish work on the head, I failed to read enough on this forum and now I think I have messed up the head and destroyed the build

Basically, I gasket matched instead of port matching and now my exhaust port looks like the "fail" pic on this thread http://www.jeepstrokers.com/forum/viewt ... b0f#p13506 (How many smacks are allowed?)

With major time and money at stake, not to mention loosing the power and torque I have been shooting for, I need some help and good advice.

Is this head salvageable with exhaust ports so open? Is the there something I can do to the headers to make this flow right? I had thought about opening up the headers to match this rediculously large exhaust port but thought it best that I should stop cutting things until I get some good input.

If there is no way to salvage this head, what are the HP and Torque losses that I would be looking at if I went ahead and used it? Is it a major loss that equates to killing all gains from the stroker work in the block?

Just need some help deciding if I made a costly mistake that can be fixed or if I need to just cut my losses and start over with a new cylinder head.

Any help is appreciated.

[Cheromaniac]

I don't think it'll be a problem but post some pics of your exhaust ports so we can judge better.

[Kapper]

It's almost identical to the "FAIL" pic shown in the other thread but more polished. I'll try to post some pics tonight. Thanks

[I6FAN]

I wouldn't say you ruined your build, but if you feel you did there's plenty of heads out there to re-do one. The build thread is also on this forum titled: Big Valve Stroker Motor by Maize583. The critique of this is somewhat suppositional; especially the part about him going "deafening silent after the build". If you read it, you'll see he under went knee surgery during this time. The builder also stated in the very begining of the thread that he was a Toyota tech, and his plans were to keep the Jeep for two years as a toy-hauler (snowmobiles), and then sell the Jeep at which time he had plans to purchase a new Toyota truck that he was wanting. He in fact did come back to this forum to sell the Jeep (slightly less than the two year period), and if I remember right, he actually removed the engine and sold it separately from the vehicle. Enough rambling already.

He did get really good flow numbers, but flow numbers aren't everything, and he did have rational for what he was doing, but my fluid/gas dynamics through pipes and orifices are not strong enough to judge. I did think he was dangerously removing too much metal (too thin in some areas) even though he was sonically checking everything. You really have to wonder though, would the "step-reversion" thing offset the increase in flow??? From what I've seen of these Jeep heads, about anything you do has to be better than stock! There was a thread on here somewhere where someone cut-up a head showing the cross section. I thought that would be good to put the in the cylinder head FAQ.

p.s. A few years ago I did a search for port wall thickness for the Jeep head and one of the things it brought up was this Big Valve build. I've been reading here ever since...this is a great site with allot of great info here!!!

[Kapper]

OK I attached a few pics of the head. One is with the gasket and the other is without. What do you guys think? Is this something I should be concerned about enough to justify scraping the head and $300 I have into it in order to start over?

[herbiehind]

this should be interesting . is the header (manifold) smaller than the exhaust port? best to look at extensive sticky on head porting . maybe it'll help hold the charge better for you particular cam ?

[SilverXJ]

If the header ports are smaller than the head exhaust ports you may want to re think.

[herbiehind]

cant the inside rim of the exhaust port be a tiny bit smaller than the gasket sometimes? this creates a ridge not wanted when gasket matching exhaust side?

[Cheromaniac]

OK I attached a few pics of the head. One is with the gasket and the other is without. What do you guys think? Is this something I should be concerned about enough to justify scraping the head and $300 I have into it in order to start over?

I wouldn't sweat it. Just bolt the head on and go. The exhaust ports might be bigger than necessary but they're still slightly smaller than the gasket so you should be OK. The valve overlap of your cam is fairly short so the likelihood of reversion is very small especially if you have a free-flowing exhaust beyond the header.

[Kapper]

OK I attached a few pics of the head. One is with the gasket and the other is without. What do you guys think? Is this something I should be concerned about enough to justify scraping the head and $300 I have into it in order to start over?

I wouldn't sweat it. Just bolt the head on and go. The exhaust ports might be bigger than necessary but they're still slightly smaller than the gasket so you should be OK. The valve overlap of your cam is fairly short so the likelihood of reversion is very small especially if you have a free-flowing exhaust beyond the header.

This is what I was hoping for. However, I'm using Comp Cam's 68-231-4 kit, will this make a difference?

[amcinstaller]

depending on which comp cam kit you bought, you may be worrying about other things. theres some parts in one of the comp kits that fits a 4.2 head specifically, and does NOT fit 4.0 heads

[Cheromaniac]

I'm using Comp Cam's 68-231-4 kit, will this make a difference?

The cam will do fine, but the CompCams valve springs won't fit in the 4.0 head spring seats and they're also too stiff. Use Mopar Performance 5249464 valve springs with matching retainers and locks instead.

[amcinstaller]

yes, springs. thanks dino, the exact part was escaping my brain when i posted

[Kapper]

I guess I don't understand the cam issue completely . I'm using a 4.0 head and block. When I ordered the cam, I ordered the kit with cam, springs, retainers, lifters, and timing set, (but no seats?)for a 4.0 from summit. The kit even states it is used for a 4.0. Help me understand why would some of these parts then only work for a 4.2? Why would this kit and springs not work in the 4.0? If the springs won't work in the 4.0 head I am wondering what is the benefit of spending the extra money to buy the kit with everything needed. Can I pre-load to counter the stiffness issue or is it best to use the mopar performance springs?

This has been a bit of a subject change, but I need all the help I can get

[Cheromaniac]

Go for the Mopar P5249464 springs with P4452032 retainers and P4529218 locks.