GM Forum - Buick, Cadillac, Olds, GMC & Pontiac chat

GM Forum - Buick, Cadillac, Olds, GMC & Pontiac chat (https://www.gmforum.com/)
-   Performance, Brainstorming & Tuning (https://www.gmforum.com/performance-brainstorming-tuning-96/)
-   -   Bought heads today!!! need feedback (https://www.gmforum.com/performance-brainstorming-tuning-96/bought-heads-today-need-feedback-267311/)

slickbonny 11-03-2007 06:25 PM

Bought heads today!!! need feedback
 
so i came across these heads 2 days ago and i saw the price go down a lil so i jumped on them today............

http://www.wbodystore.com/grandprix/...3942297549ecf4

i would really like some input as to where i should go with them when i get em. This is where i was thinkin of going............

since they have the clearance i need to put a cam in my car with the 1.9 rockers that i already have, i do plan on getting a cam. a stage 1 or a stage 2 (i wouldnt have enough clearance for the stage 3). then the Rollmaster Timing chain set so i dont have to worry about that breaking. and then take them to get a port and polish( of course after this i could also drop the pulley and maybe intercool also)... this is just a basis thought for now. i already bought the heads but the rest is under construction. i am just gonna keep it how it is for now till winter is over. by spring i plan to have all this stuff and get it all put on at once. would love some feedback. Thanx

slickbonny 11-03-2007 06:31 PM

F#%*!!!! i put this in the wrong section. move to performance and brainstorming please.

1993 SLE 11-03-2007 07:08 PM

umm, the SI valves have had a high failure rate in the past few months

including destroying 2 highly modded engines

http://www.3800pro.com/forum/showthr...ghlight=valves

slickbonny 11-03-2007 09:32 PM


Originally Posted by 1993 SLE
umm, the SI valves have had a high failure rate in the past few months

including destroying 2 highly modded engines

http://www.3800pro.com/forum/showthr...ghlight=valves

and ya i read the one incident on the valves. that could have been caused by several things. installation error, defect of part, set up of mods. did it happen multiple times? if soo then i see wut u mean. once doesnt make me worry. check em out.....http://www.wbodystore.com/grandprix/...3942297549ecf4

1993 SLE 11-03-2007 10:09 PM

yes one of the CT guys had a SI valve failure too

McGrath 11-04-2007 01:16 AM


Originally Posted by slickbonny
and ya i read the one incident on the valves. that could have been caused by several things. installation error, defect of part, set up of mods. did it happen multiple times? if soo then i see wut u mean.

It has happened many times I recommend you get some Manley valves in those heads before they go on your motor.

agrazela 11-04-2007 01:01 AM

I've read many SI valve failure stories, too.

Link to the heads says the intake valves are 1.87"...does Manley make intake valves that size for this application? AFAIK Intense lists only 1.90" intakes...the OP may need to get more machining done on those heads to go Manley.

BTW, there have been a number of recent Rollmaster timing chain failures going on, also; apparently the crank and cam sprockets don't line up right unless you get the crank sprocket keyway machined so that it fits properly. I've read JP sets don't have this problem.

slickbonny 11-04-2007 03:25 AM


Originally Posted by agrazela
I've read many SI valve failure stories, too.

Link to the heads says the intake valves are 1.87"...does Manley make intake valves that size for this application? AFAIK Intense lists only 1.90" intakes...the OP may need to get more machining done on those heads to go Manley.

BTW, there have been a number of recent Rollmaster timing chain failures going on, also; apparently the crank and cam sprockets don't line up right unless you get the crank sprocket keyway machined so that it fits properly. I've read JP sets don't have this problem.

ya i will definately prolly spend the 180 for the Manley valves. im sure there is a way to get them that size. at least i hope soo. and thanx for the info. really helps

1SSEi4U2NV 11-04-2007 10:20 AM

Those valve springs are way too much for your application and will cause your timing chain to strech and eventually snap and break your dampner. (unless your going for an all out setup (double roller, Stage 4, XPZ, etc... ). They say they will support lift up to .650" but you will not make any power at those lift values. IIRC stock heads dont make any more power over low .5xx" lift. SI valves have been known to fail with spring rates over 105 lbs., non-intercooled M90 setups, and turbo setups. This combo on these heads are going to fail eventually with any setup!

The amount of money it will get you to be able to run those safely its not worth it. I can't even believe that W-body sold those as a whole unit... that is so much negligence on there part. Personally I'd try to return tose and get your money back.

slickbonny 11-05-2007 06:29 PM


Originally Posted by 1SSEi4U2NV
Those valve springs are way too much for your application and will cause your timing chain to strech and eventually snap and break your dampner. (unless your going for an all out setup (double roller, Stage 4, XPZ, etc... ). They say they will support lift up to .650" but you will not make any power at those lift values. IIRC stock heads dont make any more power over low .5xx" lift. SI valves have been known to fail with spring rates over 105 lbs., non-intercooled M90 setups, and turbo setups. This combo on these heads are going to fail eventually with any setup!

The amount of money it will get you to be able to run those safely its not worth it. I can't even believe that W-body sold those as a whole unit... that is so much negligence on there part. Personally I'd try to return tose and get your money back.

that is wut i planned on doing. and they have clearance up to .650 but the lift wont pass .625 with 1.9's and a stage 1 cam. and i'd be gettin the double roller chain with a nice port and polish and that is some cheap performance heads. but i did decide to prolly return them and just save up for that Whipple. im done with mods till prolly christmas.


All times are GMT -4. The time now is 02:15 PM.


© 2024 MH Sub I, LLC dba Internet Brands